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id="toc-Adoption" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Adoption"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.4</span> <span>Adoption</span> </div> </a> <ul id="toc-Adoption-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Discontinuation" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Discontinuation"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.5</span> <span>Discontinuation</span> </div> </a> <ul id="toc-Discontinuation-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Technical_details" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Technical_details"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Technical details</span> </div> </a> <button aria-controls="toc-Technical_details-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Technical details subsection</span> </button> <ul id="toc-Technical_details-sublist" class="vector-toc-list"> <li id="toc-Network_structure" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Network_structure"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Network structure</span> </div> </a> <ul id="toc-Network_structure-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Base-station_subsystem" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Base-station_subsystem"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2</span> <span>Base-station subsystem</span> </div> </a> <ul id="toc-Base-station_subsystem-sublist" class="vector-toc-list"> <li id="toc-GSM_carrier_frequencies" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#GSM_carrier_frequencies"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2.1</span> <span>GSM carrier frequencies</span> </div> </a> <ul id="toc-GSM_carrier_frequencies-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Voice_codecs" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Voice_codecs"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2.2</span> <span>Voice codecs</span> </div> </a> <ul id="toc-Voice_codecs-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Subscriber_Identity_Module_(SIM)" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Subscriber_Identity_Module_(SIM)"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.3</span> <span>Subscriber Identity Module (SIM)</span> </div> </a> <ul id="toc-Subscriber_Identity_Module_(SIM)-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Phone_locking" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Phone_locking"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.4</span> <span>Phone locking</span> </div> </a> <ul id="toc-Phone_locking-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-GSM_security" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#GSM_security"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>GSM security</span> </div> </a> <ul id="toc-GSM_security-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Standards_information" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Standards_information"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Standards information</span> </div> </a> <ul id="toc-Standards_information-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-GSM_open-source_software" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#GSM_open-source_software"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>GSM open-source software</span> </div> </a> <button aria-controls="toc-GSM_open-source_software-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle GSM open-source software subsection</span> </button> <ul id="toc-GSM_open-source_software-sublist" class="vector-toc-list"> <li id="toc-Issues_with_patents_and_open_source" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Issues_with_patents_and_open_source"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1</span> <span>Issues with patents and open source</span> </div> </a> <ul id="toc-Issues_with_patents_and_open_source-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Further_reading" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Further_reading"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Further reading</span> </div> </a> <ul id="toc-Further_reading-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">GSM</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 78 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-78" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">78 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/GSM" title="GSM – Afrikaans" lang="af" hreflang="af" data-title="GSM" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target"><span>Afrikaans</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%A7%D9%84%D9%86%D8%B8%D8%A7%D9%85_%D8%A7%D9%84%D8%B9%D8%A7%D9%84%D9%85%D9%8A_%D9%84%D8%A7%D8%AA%D8%B5%D8%A7%D9%84%D8%A7%D8%AA_%D8%A7%D9%84%D9%87%D9%88%D8%A7%D8%AA%D9%81_%D8%A7%D9%84%D9%85%D8%AD%D9%85%D9%88%D9%84%D8%A9" title="النظام العالمي لاتصالات الهواتف المحمولة – Arabic" lang="ar" hreflang="ar" data-title="النظام العالمي لاتصالات الهواتف المحمولة" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/GSM" title="GSM – Azerbaijani" lang="az" hreflang="az" data-title="GSM" data-language-autonym="Azərbaycanca" data-language-local-name="Azerbaijani" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%97%E0%A7%8D%E0%A6%B2%E0%A7%8B%E0%A6%AC%E0%A6%BE%E0%A6%B2_%E0%A6%B8%E0%A6%BF%E0%A6%B8%E0%A7%8D%E0%A6%9F%E0%A7%87%E0%A6%AE_%E0%A6%AB%E0%A6%B0_%E0%A6%AE%E0%A7%8B%E0%A6%AC%E0%A6%BE%E0%A6%87%E0%A6%B2_%E0%A6%95%E0%A6%AE%E0%A6%BF%E0%A6%89%E0%A6%A8%E0%A6%BF%E0%A6%95%E0%A7%87%E0%A6%B6%E0%A6%A8%E0%A7%8D%E2%80%8C%E0%A6%B8" title="গ্লোবাল সিস্টেম ফর মোবাইল কমিউনিকেশন্‌স – Bangla" lang="bn" hreflang="bn" data-title="গ্লোবাল সিস্টেম ফর মোবাইল কমিউনিকেশন্‌স" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/GSM" title="GSM – Belarusian" lang="be" hreflang="be" data-title="GSM" data-language-autonym="Беларуская" data-language-local-name="Belarusian" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-be-x-old mw-list-item"><a href="https://be-tarask.wikipedia.org/wiki/GSM" title="GSM – Belarusian (Taraškievica orthography)" lang="be-tarask" hreflang="be-tarask" data-title="GSM" data-language-autonym="Беларуская (тарашкевіца)" data-language-local-name="Belarusian (Taraškievica orthography)" class="interlanguage-link-target"><span>Беларуская (тарашкевіца)</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/GSM" title="GSM – Bulgarian" lang="bg" hreflang="bg" data-title="GSM" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/GSM" title="GSM – Bosnian" lang="bs" hreflang="bs" data-title="GSM" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Sistema_global_per_a_comunicacions_m%C3%B2bils" title="Sistema global per a comunicacions mòbils – Catalan" lang="ca" hreflang="ca" data-title="Sistema global per a comunicacions mòbils" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/GSM" title="GSM – Czech" lang="cs" hreflang="cs" data-title="GSM" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/GSM" title="GSM – Danish" lang="da" hreflang="da" data-title="GSM" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de badge-Q17437798 badge-goodarticle mw-list-item" title="good article badge"><a href="https://de.wikipedia.org/wiki/Global_System_for_Mobile_Communications" title="Global System for Mobile Communications – German" lang="de" hreflang="de" data-title="Global System for Mobile Communications" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/GSM" title="GSM – Estonian" lang="et" hreflang="et" data-title="GSM" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/Global_System_for_Mobile_Communications" title="Global System for Mobile Communications – Greek" lang="el" hreflang="el" data-title="Global System for Mobile Communications" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Sistema_global_para_las_comunicaciones_m%C3%B3viles" title="Sistema global para las comunicaciones móviles – Spanish" lang="es" hreflang="es" data-title="Sistema global para las comunicaciones móviles" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/GSM" title="GSM – Esperanto" lang="eo" hreflang="eo" data-title="GSM" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Komunikazio_mugikorretako_sistema_orokor" title="Komunikazio mugikorretako sistema orokor – Basque" lang="eu" hreflang="eu" data-title="Komunikazio mugikorretako sistema orokor" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%AC%DB%8C%E2%80%8C%D8%A7%D8%B3%E2%80%8C%D8%A7%D9%85" title="جی‌اس‌ام – Persian" lang="fa" hreflang="fa" data-title="جی‌اس‌ام" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Global_System_for_Mobile_Communications" title="Global System for Mobile Communications – French" lang="fr" hreflang="fr" data-title="Global System for Mobile Communications" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/GSM" title="GSM – Galician" lang="gl" hreflang="gl" data-title="GSM" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/GSM" title="GSM – Korean" lang="ko" hreflang="ko" data-title="GSM" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-ha mw-list-item"><a href="https://ha.wikipedia.org/wiki/Wayar_hannu" title="Wayar hannu – Hausa" lang="ha" hreflang="ha" data-title="Wayar hannu" data-language-autonym="Hausa" data-language-local-name="Hausa" class="interlanguage-link-target"><span>Hausa</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/GSM" title="GSM – Armenian" lang="hy" hreflang="hy" data-title="GSM" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%B5%E0%A5%88%E0%A4%B6%E0%A5%8D%E0%A4%B5%E0%A4%BF%E0%A4%95_%E0%A4%AE%E0%A5%8B%E0%A4%AC%E0%A4%BE%E0%A4%87%E0%A4%B2_%E0%A4%B8%E0%A4%82%E0%A4%9A%E0%A4%BE%E0%A4%B0_%E0%A4%AA%E0%A5%8D%E0%A4%B0%E0%A4%A3%E0%A4%BE%E0%A4%B2%E0%A5%80" title="वैश्विक मोबाइल संचार प्रणाली – Hindi" lang="hi" hreflang="hi" data-title="वैश्विक मोबाइल संचार प्रणाली" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/GSM" title="GSM – Croatian" lang="hr" hreflang="hr" data-title="GSM" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Global_System_for_Mobile_Communications" title="Global System for Mobile Communications – Indonesian" lang="id" hreflang="id" data-title="Global System for Mobile Communications" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-is mw-list-item"><a href="https://is.wikipedia.org/wiki/GSM" title="GSM – Icelandic" lang="is" hreflang="is" data-title="GSM" data-language-autonym="Íslenska" data-language-local-name="Icelandic" class="interlanguage-link-target"><span>Íslenska</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Global_System_for_Mobile_Communications" title="Global System for Mobile Communications – Italian" lang="it" hreflang="it" data-title="Global System for Mobile Communications" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/GSM" title="GSM – Hebrew" lang="he" hreflang="he" data-title="GSM" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-kn mw-list-item"><a href="https://kn.wikipedia.org/wiki/%E0%B2%9C%E0%B2%BF%E0%B2%8E%E0%B2%B8%E0%B3%8D%E0%B2%8E%E0%B2%AE%E0%B3%8D" title="ಜಿಎಸ್ಎಮ್ – Kannada" lang="kn" hreflang="kn" data-title="ಜಿಎಸ್ಎಮ್" data-language-autonym="ಕನ್ನಡ" data-language-local-name="Kannada" class="interlanguage-link-target"><span>ಕನ್ನಡ</span></a></li><li class="interlanguage-link interwiki-ka mw-list-item"><a href="https://ka.wikipedia.org/wiki/GSM" title="GSM – Georgian" lang="ka" hreflang="ka" data-title="GSM" data-language-autonym="ქართული" data-language-local-name="Georgian" class="interlanguage-link-target"><span>ქართული</span></a></li><li class="interlanguage-link interwiki-sw mw-list-item"><a href="https://sw.wikipedia.org/wiki/GSM" title="GSM – Swahili" lang="sw" hreflang="sw" data-title="GSM" data-language-autonym="Kiswahili" data-language-local-name="Swahili" class="interlanguage-link-target"><span>Kiswahili</span></a></li><li class="interlanguage-link interwiki-ku mw-list-item"><a href="https://ku.wikipedia.org/wiki/Pergala_Gloverand%C3%AE_ya_Peywendiy%C3%AAn_Gerok" title="Pergala Gloverandî ya Peywendiyên Gerok – Kurdish" lang="ku" hreflang="ku" data-title="Pergala Gloverandî ya Peywendiyên Gerok" data-language-autonym="Kurdî" data-language-local-name="Kurdish" class="interlanguage-link-target"><span>Kurdî</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/GSM" title="GSM – Latvian" lang="lv" hreflang="lv" data-title="GSM" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/GSM" title="GSM – Lithuanian" lang="lt" hreflang="lt" data-title="GSM" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-lfn mw-list-item"><a href="https://lfn.wikipedia.org/wiki/GSM" title="GSM – Lingua Franca Nova" lang="lfn" hreflang="lfn" data-title="GSM" data-language-autonym="Lingua Franca Nova" data-language-local-name="Lingua Franca Nova" class="interlanguage-link-target"><span>Lingua Franca Nova</span></a></li><li class="interlanguage-link interwiki-lmo mw-list-item"><a href="https://lmo.wikipedia.org/wiki/GSM" title="GSM – Lombard" lang="lmo" hreflang="lmo" data-title="GSM" data-language-autonym="Lombard" data-language-local-name="Lombard" class="interlanguage-link-target"><span>Lombard</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/GSM" title="GSM – Hungarian" lang="hu" hreflang="hu" data-title="GSM" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/GSM" title="GSM – Macedonian" lang="mk" hreflang="mk" data-title="GSM" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%9C%E0%B4%BF.%E0%B4%8E%E0%B4%B8%E0%B5%8D.%E0%B4%8E%E0%B4%82." title="ജി.എസ്.എം. – Malayalam" lang="ml" hreflang="ml" data-title="ജി.എസ്.എം." data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-mr mw-list-item"><a href="https://mr.wikipedia.org/wiki/%E0%A4%97%E0%A5%8D%E0%A4%B2%E0%A5%8B%E0%A4%AC%E0%A4%B2_%E0%A4%B8%E0%A4%BF%E0%A4%B8%E0%A5%8D%E0%A4%9F%E0%A4%AE_%E0%A4%AB%E0%A5%89%E0%A4%B0_%E0%A4%AE%E0%A5%8B%E0%A4%AC%E0%A4%BE%E0%A4%87%E0%A4%B2_%E0%A4%95%E0%A4%AE%E0%A5%8D%E0%A4%AF%E0%A5%81%E0%A4%A8%E0%A4%BF%E0%A4%95%E0%A5%87%E0%A4%B6%E0%A4%A8" title="ग्लोबल सिस्टम फॉर मोबाइल कम्युनिकेशन – Marathi" lang="mr" hreflang="mr" data-title="ग्लोबल सिस्टम फॉर मोबाइल कम्युनिकेशन" data-language-autonym="मराठी" data-language-local-name="Marathi" class="interlanguage-link-target"><span>मराठी</span></a></li><li class="interlanguage-link interwiki-xmf mw-list-item"><a href="https://xmf.wikipedia.org/wiki/GSM" title="GSM – Mingrelian" lang="xmf" hreflang="xmf" data-title="GSM" data-language-autonym="მარგალური" data-language-local-name="Mingrelian" class="interlanguage-link-target"><span>მარგალური</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/GSM" title="GSM – Malay" lang="ms" hreflang="ms" data-title="GSM" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-my mw-list-item"><a href="https://my.wikipedia.org/wiki/%E1%80%82%E1%80%BB%E1%80%AE%E1%80%A1%E1%80%80%E1%80%BA%E1%80%85%E1%80%BA%E1%80%A1%E1%80%99%E1%80%BA" title="ဂျီအက်စ်အမ် – Burmese" lang="my" hreflang="my" data-title="ဂျီအက်စ်အမ်" data-language-autonym="မြန်မာဘာသာ" data-language-local-name="Burmese" class="interlanguage-link-target"><span>မြန်မာဘာသာ</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Gsm_(communicatie)" title="Gsm (communicatie) – Dutch" lang="nl" hreflang="nl" data-title="Gsm (communicatie)" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ne mw-list-item"><a href="https://ne.wikipedia.org/wiki/%E0%A4%B5%E0%A4%BF%E0%A4%B6%E0%A5%8D%E0%A4%B5%E0%A4%B5%E0%A5%8D%E0%A4%AF%E0%A4%BE%E0%A4%AA%E0%A5%80_%E0%A4%AE%E0%A5%8B%E0%A4%AC%E0%A4%BE%E0%A4%87%E0%A4%B2_%E0%A4%B8%E0%A4%9E%E0%A5%8D%E0%A4%9A%E0%A4%BE%E0%A4%B0_%E0%A4%AA%E0%A5%8D%E0%A4%B0%E0%A4%A3%E0%A4%BE%E0%A4%B2%E0%A5%80" title="विश्वव्यापी मोबाइल सञ्चार प्रणाली – Nepali" lang="ne" hreflang="ne" data-title="विश्वव्यापी मोबाइल सञ्चार प्रणाली" data-language-autonym="नेपाली" data-language-local-name="Nepali" class="interlanguage-link-target"><span>नेपाली</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/GSM" title="GSM – Japanese" lang="ja" hreflang="ja" data-title="GSM" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/GSM" title="GSM – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="GSM" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/GSM" title="GSM – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="GSM" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/GSM" title="GSM – Uzbek" lang="uz" hreflang="uz" data-title="GSM" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="Uzbek" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-pap mw-list-item"><a href="https://pap.wikipedia.org/wiki/GSM" title="GSM – Papiamento" lang="pap" hreflang="pap" data-title="GSM" data-language-autonym="Papiamentu" data-language-local-name="Papiamento" class="interlanguage-link-target"><span>Papiamentu</span></a></li><li class="interlanguage-link interwiki-ps mw-list-item"><a href="https://ps.wikipedia.org/wiki/%D8%AC%D9%8A_%D8%A7%D8%B3_%D8%A7%D9%85" title="جي اس ام – Pashto" lang="ps" hreflang="ps" data-title="جي اس ام" data-language-autonym="پښتو" data-language-local-name="Pashto" class="interlanguage-link-target"><span>پښتو</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/GSM" title="GSM – Polish" lang="pl" hreflang="pl" data-title="GSM" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/GSM" title="GSM – Portuguese" lang="pt" hreflang="pt" data-title="GSM" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/GSM" title="GSM – Romanian" lang="ro" hreflang="ro" data-title="GSM" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/GSM" title="GSM – Russian" lang="ru" hreflang="ru" data-title="GSM" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sq mw-list-item"><a href="https://sq.wikipedia.org/wiki/GSM" title="GSM – Albanian" lang="sq" hreflang="sq" data-title="GSM" data-language-autonym="Shqip" data-language-local-name="Albanian" class="interlanguage-link-target"><span>Shqip</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/GSM" title="GSM – Simple English" lang="en-simple" hreflang="en-simple" data-title="GSM" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Glob%C3%A1lny_syst%C3%A9m_mobiln%C3%BDch_komunik%C3%A1ci%C3%AD" title="Globálny systém mobilných komunikácií – Slovak" lang="sk" hreflang="sk" data-title="Globálny systém mobilných komunikácií" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/GSM" title="GSM – Slovenian" lang="sl" hreflang="sl" data-title="GSM" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-so mw-list-item"><a href="https://so.wikipedia.org/wiki/GSM" title="GSM – Somali" lang="so" hreflang="so" data-title="GSM" data-language-autonym="Soomaaliga" data-language-local-name="Somali" class="interlanguage-link-target"><span>Soomaaliga</span></a></li><li class="interlanguage-link interwiki-ckb mw-list-item"><a href="https://ckb.wikipedia.org/wiki/%D8%AC%DB%8C_%D8%A6%DB%8E%D8%B3_%D8%A6%DB%8E%D9%85" title="جی ئێس ئێم – Central Kurdish" lang="ckb" hreflang="ckb" data-title="جی ئێس ئێم" data-language-autonym="کوردی" data-language-local-name="Central Kurdish" class="interlanguage-link-target"><span>کوردی</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/GSM" title="GSM – Serbian" lang="sr" hreflang="sr" data-title="GSM" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/GSM" title="GSM – Serbo-Croatian" lang="sh" hreflang="sh" data-title="GSM" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-su mw-list-item"><a href="https://su.wikipedia.org/wiki/GSM" title="GSM – Sundanese" lang="su" hreflang="su" data-title="GSM" data-language-autonym="Sunda" data-language-local-name="Sundanese" class="interlanguage-link-target"><span>Sunda</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/GSM" title="GSM – Finnish" lang="fi" hreflang="fi" data-title="GSM" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/GSM" title="GSM – Swedish" lang="sv" hreflang="sv" data-title="GSM" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%89%E0%AE%B2%E0%AE%95%E0%AE%B3%E0%AE%BE%E0%AE%B5%E0%AE%BF%E0%AE%AF_%E0%AE%A8%E0%AE%9F%E0%AE%AE%E0%AE%BE%E0%AE%9F%E0%AF%81%E0%AE%AE%E0%AF%8D_%E0%AE%A4%E0%AE%95%E0%AE%B5%E0%AE%B2%E0%AF%8D_%E0%AE%A4%E0%AF%8A%E0%AE%9F%E0%AE%B0%E0%AF%8D%E0%AE%AA%E0%AF%81%E0%AE%95%E0%AE%B3%E0%AF%8D_%E0%AE%A4%E0%AE%BF%E0%AE%9F%E0%AF%8D%E0%AE%9F%E0%AE%AE%E0%AF%8D" title="உலகளாவிய நடமாடும் தகவல் தொடர்புகள் திட்டம் – Tamil" lang="ta" hreflang="ta" data-title="உலகளாவிய நடமாடும் தகவல் தொடர்புகள் திட்டம்" data-language-autonym="தமிழ்" data-language-local-name="Tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-roa-tara mw-list-item"><a href="https://roa-tara.wikipedia.org/wiki/GSM" title="GSM – Tarantino" lang="nap-x-tara" hreflang="nap-x-tara" data-title="GSM" data-language-autonym="Tarandíne" data-language-local-name="Tarantino" class="interlanguage-link-target"><span>Tarandíne</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B8%88%E0%B8%B5%E0%B9%80%E0%B8%AD%E0%B8%AA%E0%B9%80%E0%B8%AD%E0%B9%87%E0%B8%A1" title="จีเอสเอ็ม – Thai" lang="th" hreflang="th" data-title="จีเอสเอ็ม" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/GSM" title="GSM – Turkish" lang="tr" hreflang="tr" data-title="GSM" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/GSM" title="GSM – Ukrainian" lang="uk" hreflang="uk" data-title="GSM" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-ur mw-list-item"><a href="https://ur.wikipedia.org/wiki/%D8%AC%DB%8C_%D8%A7%DB%8C%D8%B3_%D8%A7%DB%8C%D9%85" title="جی ایس ایم – Urdu" lang="ur" hreflang="ur" data-title="جی ایس ایم" data-language-autonym="اردو" data-language-local-name="Urdu" class="interlanguage-link-target"><span>اردو</span></a></li><li class="interlanguage-link interwiki-vec mw-list-item"><a href="https://vec.wikipedia.org/wiki/Global_System_for_Mobile_Communications" title="Global System for Mobile Communications – Venetian" lang="vec" hreflang="vec" data-title="Global System for Mobile Communications" data-language-autonym="Vèneto" data-language-local-name="Venetian" class="interlanguage-link-target"><span>Vèneto</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/H%E1%BB%87_th%E1%BB%91ng_th%C3%B4ng_tin_di_%C4%91%E1%BB%99ng_to%C3%A0n_c%E1%BA%A7u" title="Hệ thống thông tin di động toàn cầu – Vietnamese" lang="vi" hreflang="vi" data-title="Hệ thống thông tin di động toàn cầu" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-wuu mw-list-item"><a href="https://wuu.wikipedia.org/wiki/GSM" title="GSM – Wu" lang="wuu" hreflang="wuu" data-title="GSM" data-language-autonym="吴语" data-language-local-name="Wu" class="interlanguage-link-target"><span>吴语</span></a></li><li class="interlanguage-link interwiki-bat-smg mw-list-item"><a href="https://bat-smg.wikipedia.org/wiki/GSM" title="GSM – Samogitian" lang="sgs" hreflang="sgs" data-title="GSM" data-language-autonym="Žemaitėška" data-language-local-name="Samogitian" class="interlanguage-link-target"><span>Žemaitėška</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/GSM" title="GSM – Chinese" lang="zh" hreflang="zh" data-title="GSM" data-language-autonym="中文" data-language-local-name="Chinese" 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dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Cellular telephone network standard</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">For other uses, see <a href="/wiki/GSM_(disambiguation)" class="mw-disambig" title="GSM (disambiguation)">GSM (disambiguation)</a>.</div> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><style data-mw-deduplicate="TemplateStyles:r1242257876">.mw-parser-output .ib-company .infobox-label{padding-right:0.5em}.mw-parser-output .ib-company .infobox-data,.mw-parser-output .ib-company .infobox-below{line-height:1.35em}.mw-parser-output .ib-company-logo img{background-color:#f8f9fa}.mw-parser-output .ib-company-locality,.mw-parser-output .ib-company-country{display:inline}</style><table class="infobox ib-company vcard"><caption class="infobox-title fn org">GSM</caption><tbody><tr><td colspan="2" class="infobox-image ib-company-logo logo"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:GSMLogo.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5d/GSMLogo.svg/220px-GSMLogo.svg.png" decoding="async" width="220" height="132" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5d/GSMLogo.svg/330px-GSMLogo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5d/GSMLogo.svg/440px-GSMLogo.svg.png 2x" data-file-width="250" data-file-height="150" /></a></span><div class="infobox-caption">The GSM logo is used to identify compatible devices and equipment. The dots symbolize three clients in the home network and one roaming client.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup></div></td></tr><tr><th scope="row" class="infobox-label">Industry</th><td class="infobox-data category"><a href="/wiki/Telecommunications" title="Telecommunications">Telecommunications</a></td></tr><tr><th scope="row" class="infobox-label">Founded</th><td class="infobox-data">December 1991<span class="noprint">; 32 years ago</span><span style="display:none"> (<span class="bday dtstart published updated">December 1991</span>)</span></td></tr><tr><th scope="row" class="infobox-label">Successor</th><td class="infobox-data"><a href="/wiki/3G" title="3G">3G</a> <span class="penicon autoconfirmed-show"><span class="mw-valign-text-top" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q46904?uselang=en#P156" title="Edit this on Wikidata"><img alt="Edit this on Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></span></td></tr><tr><th scope="row" class="infobox-label">Products</th><td class="infobox-data">Digital cellular networks</td></tr><tr><th scope="row" class="infobox-label">Website</th><td class="infobox-data"><span class="url"><a rel="nofollow" class="external text" href="https://www.gsma.com/">www<wbr />.gsma<wbr />.com</a></span></td></tr></tbody></table> <p> The <b>Global System for Mobile Communications</b> (<b>GSM</b>) is a standard developed by the <a href="/wiki/European_Telecommunications_Standards_Institute" title="European Telecommunications Standards Institute">European Telecommunications Standards Institute</a> (ETSI) to describe the protocols for second-generation (<a href="/wiki/2G" title="2G">2G</a>) digital <a href="/wiki/Cellular_network" title="Cellular network">cellular networks</a> used by mobile devices such as mobile phones and tablets. GSM is also a <a href="/wiki/Trade_mark" class="mw-redirect" title="Trade mark">trade mark</a> owned by the <a href="/wiki/GSM_Association" class="mw-redirect" title="GSM Association">GSM Association</a>.<sup id="cite_ref-:0_2-0" class="reference"><a href="#cite_note-:0-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> "<a href="/wiki/GSM_(codec)" class="mw-redirect" title="GSM (codec)">GSM</a>" may also refer to the voice codec initially used in GSM.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p>It was first implemented in <a href="/wiki/Finland" title="Finland">Finland</a> in December 1991.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> By the mid-2010s, it became a global standard for mobile communications achieving over 90% market share, and operating in over 193 countries and territories.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p><p>2G networks developed as a replacement for first generation (<a href="/wiki/1G" title="1G">1G</a>) analog cellular networks. The GSM standard originally described a digital, circuit-switched network optimized for <a href="/wiki/Duplex_(telecommunications)#Full_duplex" title="Duplex (telecommunications)">full duplex</a> voice <a href="/wiki/Telephony" title="Telephony">telephony</a>. This expanded over time to include data communications, first by <a href="/wiki/Circuit_Switched_Data" title="Circuit Switched Data">circuit-switched transport</a>, then by <a href="/wiki/Network_packet" title="Network packet">packet</a> data transport via <a href="/wiki/General_Packet_Radio_Service" title="General Packet Radio Service">General Packet Radio Service</a> (GPRS), and <a href="/wiki/Enhanced_Data_Rates_for_GSM_Evolution" class="mw-redirect" title="Enhanced Data Rates for GSM Evolution">Enhanced Data Rates for GSM Evolution</a> (EDGE). </p><p>Subsequently, the <a href="/wiki/3GPP" title="3GPP">3GPP</a> developed third-generation (<a href="/wiki/3G" title="3G">3G</a>) <a href="/wiki/UMTS" title="UMTS">UMTS</a> standards, followed by the fourth-generation (<a href="/wiki/4G" title="4G">4G</a>) LTE Advanced and the fifth-generation <a href="/wiki/5G" title="5G">5G</a> standards, which do not form part of the ETSI GSM standard. </p><p>Beginning in the late 2010s, various carriers worldwide <a href="#Discontinuation">started to shut down their GSM networks</a>. Nevertheless, as a result of the network's widespread use, the acronym "GSM" is still used as a generic term for the plethora of <i>G</i> mobile phone technologies evolved from it. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=1" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Initial_European_development">Initial European development</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=2" title="Edit section: Initial European development"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Dupuis_Haug_GSM_around_1990.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/ee/Dupuis_Haug_GSM_around_1990.jpg/220px-Dupuis_Haug_GSM_around_1990.jpg" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/ee/Dupuis_Haug_GSM_around_1990.jpg/330px-Dupuis_Haug_GSM_around_1990.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/ee/Dupuis_Haug_GSM_around_1990.jpg/440px-Dupuis_Haug_GSM_around_1990.jpg 2x" data-file-width="2220" data-file-height="1484" /></a><figcaption>Thomas Haug (first GSM president) and Philippe Dupuis (second GSM president) during a GSM meeting in Belgium, April 1992</figcaption></figure> <p>In 1983, work began to develop a European standard for digital cellular voice telecommunications when the <a href="/wiki/European_Conference_of_Postal_and_Telecommunications_Administrations" title="European Conference of Postal and Telecommunications Administrations">European Conference of Postal and Telecommunications Administrations</a> (CEPT) set up the <i>Groupe Spécial Mobile</i> (GSM) committee and later provided a permanent technical-support group based in <a href="/wiki/Paris" title="Paris">Paris</a>. Five years later, in 1987, 15 representatives from 13 European countries signed a <a href="/wiki/Memorandum_of_understanding" title="Memorandum of understanding">memorandum of understanding</a> in <a href="/wiki/Copenhagen" title="Copenhagen">Copenhagen</a> to develop and deploy a common cellular telephone system across Europe, and EU rules were passed to make GSM a mandatory standard.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> The decision to develop a continental standard eventually resulted in a unified, open, standard-based network which was larger than that in the United States.<sup id="cite_ref-zdnet_birthday_7-0" class="reference"><a href="#cite_note-zdnet_birthday-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-etsi_gsm_8-0" class="reference"><a href="#cite_note-etsi_gsm-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-gsmworld_history_9-0" class="reference"><a href="#cite_note-gsmworld_history-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-etsi_cellhist_10-0" class="reference"><a href="#cite_note-etsi_cellhist-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> </p><p>In February 1987 Europe produced the first agreed GSM Technical Specification. Ministers from the four big EU countries cemented their political support for GSM with the Bonn Declaration on Global Information Networks in May and the GSM <a href="/wiki/Memorandum_of_understanding" title="Memorandum of understanding">MoU</a> was tabled for signature in September. The MoU drew in mobile operators from across Europe to pledge to invest in new GSM networks to an ambitious common date. </p><p>In this short 38-week period the whole of Europe (countries and industries) had been brought behind GSM in a rare unity and speed guided by four public officials: Armin Silberhorn (Germany), Stephen Temple (UK), <a href="/wiki/Philippe_Dupuis_(engineer)" title="Philippe Dupuis (engineer)">Philippe Dupuis</a> (France), and Renzo Failli (Italy).<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> In 1989 the Groupe Spécial Mobile committee was transferred from CEPT to the <a href="/wiki/European_Telecommunications_Standards_Institute" title="European Telecommunications Standards Institute">European Telecommunications Standards Institute</a> (ETSI).<sup id="cite_ref-etsi_gsm_8-1" class="reference"><a href="#cite_note-etsi_gsm-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-gsmworld_history_9-1" class="reference"><a href="#cite_note-gsmworld_history-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-etsi_cellhist_10-1" class="reference"><a href="#cite_note-etsi_cellhist-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> The IEEE/RSE awarded to <a href="/wiki/Thomas_Haug" title="Thomas Haug">Thomas Haug</a> and <a href="/wiki/Philippe_Dupuis_(engineer)" title="Philippe Dupuis (engineer)">Philippe Dupuis</a> the 2018 <a href="/wiki/IEEE/RSE_James_Clerk_Maxwell_Medal" title="IEEE/RSE James Clerk Maxwell Medal">James Clerk Maxwell medal</a> for their "leadership in the development of the first international mobile communications standard with subsequent evolution into worldwide smartphone data communication".<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> The GSM (2G) has evolved into 3G, 4G and 5G. </p> <div class="mw-heading mw-heading3"><h3 id="First_networks">First networks</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=3" title="Edit section: First networks"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:GSM-Telefone-1991.jpg" class="mw-file-description"><img alt="Prototype GSM phones from 1991" src="//upload.wikimedia.org/wikipedia/commons/thumb/7/74/GSM-Telefone-1991.jpg/220px-GSM-Telefone-1991.jpg" decoding="async" width="220" height="229" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/74/GSM-Telefone-1991.jpg/330px-GSM-Telefone-1991.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/74/GSM-Telefone-1991.jpg/440px-GSM-Telefone-1991.jpg 2x" data-file-width="1928" data-file-height="2004" /></a><figcaption>Prototype GSM phones</figcaption></figure> <p>In parallel <a href="/wiki/France" title="France">France</a> and <a href="/wiki/Germany" title="Germany">Germany</a> signed a joint development agreement in 1984 and were joined by <a href="/wiki/Italy" title="Italy">Italy</a> and the <a href="/wiki/United_Kingdom" title="United Kingdom">UK</a> in 1986. In 1986, the <a href="/wiki/European_Commission" title="European Commission">European Commission</a> proposed reserving the 900 MHz spectrum band for GSM. It was long believed that the former <a href="/wiki/Finland" title="Finland">Finnish</a> prime minister <a href="/wiki/Harri_Holkeri" title="Harri Holkeri">Harri Holkeri</a> made the world's first GSM call on 1 July 1991, calling <a href="/wiki/Kaarina_Suonio" title="Kaarina Suonio">Kaarina Suonio</a> (deputy mayor of the city of <a href="/wiki/Tampere" title="Tampere">Tampere</a>) using a network built by <a href="/wiki/Nokia_Siemens_Networks" class="mw-redirect" title="Nokia Siemens Networks">Nokia and Siemens</a> and <a href="/wiki/Mobile_network_operator" title="Mobile network operator">operated</a> by <a href="/wiki/Radiolinja" title="Radiolinja">Radiolinja</a>.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> In 2021 a former Nokia engineer <a href="/w/index.php?title=Pekka_Lonka&action=edit&redlink=1" class="new" title="Pekka Lonka (page does not exist)">Pekka Lonka</a> revealed to <span title="Finnish-language text"><i lang="fi"><a href="/wiki/Helsingin_Sanomat" title="Helsingin Sanomat">Helsingin Sanomat</a></i></span> making a test call just a couple of hours earlier. "World's first GSM call was actually made by me. I called Marjo Jousinen, in Salo.", Lonka informed.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> The following year saw the sending of the first <a href="/wiki/Short_messaging_service" class="mw-redirect" title="Short messaging service">short messaging service</a> (SMS or "text message") message, and <a href="/wiki/Vodafone_UK" title="Vodafone UK">Vodafone UK</a> and Telecom Finland signed the first international <a href="/wiki/Roaming" title="Roaming">roaming</a> agreement. </p> <div class="mw-heading mw-heading3"><h3 id="Enhancements">Enhancements</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=4" title="Edit section: Enhancements"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Work began in 1991 to expand the GSM standard to the 1800 MHz frequency band and the first 1800 MHz network became operational in the UK by 1993, called the DCS 1800. Also that year, <a href="/wiki/Telstra" title="Telstra">Telstra</a> became the first network operator to deploy a GSM network outside Europe and the first practical hand-held GSM <a href="/wiki/Mobile_phone" title="Mobile phone">mobile phone</a> became available. </p><p>In 1995 fax, data and SMS messaging services were launched commercially, the first 1900 MHz GSM network became operational in the United States and GSM subscribers worldwide exceeded 10 million. In the same year, the <a href="/wiki/GSM_Association" class="mw-redirect" title="GSM Association">GSM Association</a> formed. Pre-paid GSM SIM cards were launched in 1996 and worldwide GSM subscribers passed 100 million in 1998.<sup id="cite_ref-gsmworld_history_9-2" class="reference"><a href="#cite_note-gsmworld_history-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p><p>In 2000 the first commercial <a href="/wiki/General_Packet_Radio_Service" title="General Packet Radio Service">General Packet Radio Service</a> (GPRS) services were launched and the first GPRS-compatible handsets became available for sale. In 2001, the first UMTS (W-CDMA) network was launched, a 3G technology that is not part of GSM. Worldwide GSM subscribers exceeded 500 million. In 2002, the first <a href="/wiki/Multimedia_Messaging_Service" title="Multimedia Messaging Service">Multimedia Messaging Service</a> (MMS) was introduced and the first GSM network in the 800 MHz frequency band became operational. <a href="/wiki/Enhanced_Data_rates_for_GSM_Evolution" title="Enhanced Data rates for GSM Evolution">Enhanced Data rates for GSM Evolution</a> (EDGE) services first became operational in a network in 2003, and the number of worldwide GSM subscribers exceeded 1 billion in 2004.<sup id="cite_ref-gsmworld_history_9-3" class="reference"><a href="#cite_note-gsmworld_history-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p><p>By 2005 GSM networks accounted for more than 75% of the worldwide cellular network market, serving 1.5 billion subscribers. In 2005, the first <a href="/wiki/HSDPA" class="mw-redirect" title="HSDPA">HSDPA</a>-capable network also became operational. The first <a href="/wiki/HSUPA" class="mw-redirect" title="HSUPA">HSUPA</a> network launched in 2007. (<a href="/wiki/High_Speed_Packet_Access" title="High Speed Packet Access">High Speed Packet Access</a> (HSPA) and its uplink and downlink versions are 3G technologies, not part of GSM.) Worldwide GSM subscribers exceeded three billion in 2008.<sup id="cite_ref-gsmworld_history_9-4" class="reference"><a href="#cite_note-gsmworld_history-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Adoption">Adoption</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=5" title="Edit section: Adoption"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The <a href="/wiki/GSM_Association" class="mw-redirect" title="GSM Association">GSM Association</a> estimated in 2011 that technologies defined in the GSM standard served 80% of the mobile market, encompassing more than 5 billion people across more than 212 countries and territories, making GSM the most ubiquitous of the many standards for cellular networks.<sup id="cite_ref-gsma_stats_15-0" class="reference"><a href="#cite_note-gsma_stats-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>GSM is a second-generation (2G) standard employing time-division multiple-access (TDMA) spectrum-sharing, issued by the European Telecommunications Standards Institute (ETSI). The GSM standard does not include the 3G <a href="/wiki/Universal_Mobile_Telecommunications_System" class="mw-redirect" title="Universal Mobile Telecommunications System">Universal Mobile Telecommunications System</a> (UMTS), <a href="/wiki/Code-division_multiple_access" title="Code-division multiple access">code-division multiple access</a> (CDMA) technology, nor the 4G LTE <a href="/wiki/Orthogonal_frequency-division_multiple_access" title="Orthogonal frequency-division multiple access">orthogonal frequency-division multiple access</a> (OFDMA) technology standards issued by the 3GPP.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p><p>GSM, for the first time, set a common standard for Europe for wireless networks. It was also adopted by many countries outside Europe. This allowed subscribers to use other GSM networks that have roaming agreements with each other. The common standard reduced research and development costs, since hardware and software could be sold with only minor adaptations for the local market.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Discontinuation">Discontinuation</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=6" title="Edit section: Discontinuation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/2G#Phase-out" title="2G">2G § Phase-out</a></div> <p><a href="/wiki/Telstra" title="Telstra">Telstra</a> in <a href="/wiki/Australia" title="Australia">Australia</a> shut down its 2G GSM network on 1 December 2016, the first mobile network operator to decommission a GSM network.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> The second mobile provider to shut down its GSM network (on 1 January 2017) was <a href="/wiki/AT%26T_Mobility" title="AT&T Mobility">AT&T Mobility</a> from the <a href="/wiki/United_States" title="United States">United States</a>.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Optus" title="Optus">Optus</a> in <a href="/wiki/Australia" title="Australia">Australia</a> completed the shut down of its 2G GSM network on 1 August 2017, part of the Optus GSM network covering <a href="/wiki/Western_Australia" title="Western Australia">Western Australia</a> and the <a href="/wiki/Northern_Territory" title="Northern Territory">Northern Territory</a> had earlier in the year been shut down in April 2017.<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Singapore" title="Singapore">Singapore</a> shut down 2G services entirely in April 2017.<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Technical_details">Technical details</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=7" title="Edit section: Technical details"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Gsm_structures.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Gsm_structures.svg/350px-Gsm_structures.svg.png" decoding="async" width="350" height="213" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Gsm_structures.svg/525px-Gsm_structures.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Gsm_structures.svg/700px-Gsm_structures.svg.png 2x" data-file-width="868" data-file-height="529" /></a><figcaption>The structure of a GSM network</figcaption></figure> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/GSM_services" title="GSM services">GSM services</a></div> <div class="mw-heading mw-heading3"><h3 id="Network_structure">Network structure</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=8" title="Edit section: Network structure"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The network is structured into several discrete sections: </p> <ul><li><a href="/wiki/Base_station_subsystem" title="Base station subsystem">Base station subsystem</a> – the base stations and their controllers</li> <li><a href="/wiki/Network_and_Switching_Subsystem" class="mw-redirect" title="Network and Switching Subsystem">Network and Switching Subsystem</a> – the part of the network most similar to a fixed network, sometimes just called the "core network"</li> <li><a href="/wiki/GPRS_Core_Network" class="mw-redirect" title="GPRS Core Network">GPRS Core Network</a> – the optional part which allows packet-based Internet connections</li> <li><a href="/wiki/Operations_support_system" title="Operations support system">Operations support system</a> (OSS) – network maintenance</li></ul> <div class="mw-heading mw-heading3"><h3 id="Base-station_subsystem">Base-station subsystem</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=9" title="Edit section: Base-station subsystem"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Base_station_subsystem" title="Base station subsystem">Base station subsystem</a></div> <figure typeof="mw:File/Thumb"><a href="/wiki/File:Kathrein_antenna.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Kathrein_antenna.jpg/150px-Kathrein_antenna.jpg" decoding="async" width="150" height="423" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Kathrein_antenna.jpg/225px-Kathrein_antenna.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Kathrein_antenna.jpg/300px-Kathrein_antenna.jpg 2x" data-file-width="1541" data-file-height="4349" /></a><figcaption>GSM <a href="/wiki/Cell_site" title="Cell site">cell site</a> antennas in the <a href="/wiki/Deutsches_Museum" title="Deutsches Museum">Deutsches Museum</a>, <a href="/wiki/Munich" title="Munich">Munich</a>, <a href="/wiki/Germany" title="Germany">Germany</a></figcaption></figure> <p>GSM utilizes a <a href="/wiki/Cellular_network" title="Cellular network">cellular network</a>, meaning that <a href="/wiki/Cell_phone" class="mw-redirect" title="Cell phone">cell phones</a> connect to it by searching for cells in the immediate vicinity. There are five different cell sizes in a GSM network: </p> <ul><li><a href="/wiki/Macrocell" title="Macrocell">macro</a></li> <li><a href="/wiki/Microcell" title="Microcell">micro</a></li> <li><a href="/wiki/Picocell" title="Picocell">pico</a></li> <li><a href="/wiki/Femtocell" title="Femtocell">femto</a>, and</li> <li>umbrella cells</li></ul> <p>The coverage area of each cell varies according to the implementation environment. Macro cells can be regarded as cells where the <a href="/wiki/Base_station" title="Base station">base-station</a> <a href="/wiki/Antenna_(electronics)" class="mw-redirect" title="Antenna (electronics)">antenna</a> is installed on a mast or a building above average rooftop level. Micro cells are cells whose antenna height is under average rooftop level; they are typically deployed in urban areas. Picocells are small cells whose coverage diameter is a few dozen meters; they are mainly used indoors. Femtocells are cells designed for use in residential or <a href="/wiki/Small_business" title="Small business">small-business</a> environments and connect to a <a href="/wiki/Telecommunications_service_provider" class="mw-redirect" title="Telecommunications service provider">telecommunications service provider</a>'s network via a <a href="/wiki/Broadband_internet" class="mw-redirect" title="Broadband internet">broadband-internet</a> connection. Umbrella cells are used to cover shadowed regions of smaller cells and to fill in gaps in coverage between those cells. </p><p>Cell horizontal radius varies – depending on antenna height, <a href="/wiki/Antenna_gain" class="mw-redirect" title="Antenna gain">antenna gain</a>, and <a href="/wiki/Propagation_(disambiguation)" class="mw-redirect mw-disambig" title="Propagation (disambiguation)">propagation</a> conditions – from a couple of hundred meters to several tens of kilometers. The longest distance the GSM specification supports in practical use is 35 kilometres (22 mi). There are also several implementations of the concept of an extended cell,<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> where the cell radius could be double or even more, depending on the antenna system, the type of terrain, and the <a href="/wiki/Timing_advance" title="Timing advance">timing advance</a>. </p><p>GSM supports indoor coverage – achievable by using an indoor picocell base station, or an <a href="/wiki/Cellular_repeater" title="Cellular repeater">indoor repeater</a> with distributed indoor antennas fed through power splitters – to deliver the radio signals from an antenna outdoors to the separate indoor distributed antenna system. Picocells are typically deployed when significant call capacity is needed indoors, as in shopping centers or airports. However, this is not a prerequisite, since indoor coverage is also provided by in-building penetration of radio signals from any nearby cell. </p> <div class="mw-heading mw-heading4"><h4 id="GSM_carrier_frequencies">GSM carrier frequencies</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=10" title="Edit section: GSM carrier frequencies"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/GSM_frequency_bands" title="GSM frequency bands">GSM frequency bands</a></div> <p>GSM networks operate in a number of different <a href="/wiki/Carrier_frequency" class="mw-redirect" title="Carrier frequency">carrier frequency</a> ranges (separated into <a href="/wiki/GSM_frequency_ranges" class="mw-redirect" title="GSM frequency ranges">GSM frequency ranges</a> for 2G and <a href="/wiki/UMTS_frequency_bands" title="UMTS frequency bands">UMTS frequency bands</a> for 3G), with most <a href="/wiki/2G" title="2G">2G</a> GSM networks operating in the 900 MHz or 1800 MHz bands. Where these bands were already allocated, the 850 MHz and 1900 MHz bands were used instead (for example in Canada and the United States). In rare cases the 400 and 450 MHz frequency bands are assigned in some countries because they were previously used for first-generation systems. </p><p>For comparison, most <a href="/wiki/3G" title="3G">3G</a> networks in Europe operate in the 2100 MHz frequency band. For more information on worldwide GSM frequency usage, see <a href="/wiki/GSM_frequency_bands" title="GSM frequency bands">GSM frequency bands</a>. </p><p>Regardless of the frequency selected by an operator, it is divided into <a href="/wiki/Time-division_multiplexing" title="Time-division multiplexing">timeslots</a> for individual phones. This allows eight full-rate or sixteen half-rate speech channels per <a href="/wiki/Radio_frequency" title="Radio frequency">radio frequency</a>. These eight radio timeslots (or <a href="/wiki/Burst_transmission" title="Burst transmission">burst</a> periods) are grouped into a <a href="/wiki/Time-division_multiple_access" title="Time-division multiple access">TDMA</a> frame. Half-rate channels use alternate frames in the same timeslot. The channel data rate for all <span class="nowrap">8 channels</span> is <span class="nowrap">270.833 kbit/s,</span> and the frame duration is <span class="nowrap">4.615 ms.</span><sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> TDMA noise is interference that can be heard on speakers near a GSM phone using TDMA, audible as a buzzing sound.<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> </p><p>The transmission power in the handset is limited to a maximum of 2 watts in <span class="nowrap">GSM 850/900</span> and <span class="nowrap">1 watt</span> in <span class="nowrap">GSM 1800/1900</span>. </p> <div class="mw-heading mw-heading4"><h4 id="Voice_codecs">Voice codecs</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=11" title="Edit section: Voice codecs"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>GSM has used a variety of voice <a href="/wiki/Codec" title="Codec">codecs</a> to squeeze 3.1 kHz audio into between 7 and 13 kbit/s. Originally, two codecs, named after the types of data channel they were allocated, were used, called <a href="/wiki/Half_Rate" title="Half Rate">Half Rate</a> (6.5 kbit/s) and <a href="/wiki/Full_Rate" title="Full Rate">Full Rate</a> (13 kbit/s). These used a system based on <a href="/wiki/Linear_predictive_coding" title="Linear predictive coding">linear predictive coding</a> (LPC). In addition to being efficient with <a href="/wiki/Bitrate" class="mw-redirect" title="Bitrate">bitrates</a>, these codecs also made it easier to identify more important parts of the audio, allowing the air interface layer to prioritize and better protect these parts of the signal. GSM was further enhanced in 1997<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> with the <a href="/wiki/Enhanced_full_rate" title="Enhanced full rate">enhanced full rate</a> (EFR) codec, a 12.2 kbit/s codec that uses a full-rate channel. Finally, with the development of <a href="/wiki/UMTS" title="UMTS">UMTS</a>, EFR was refactored into a variable-rate codec called <a href="/wiki/Adaptive_Multi-Rate" class="mw-redirect" title="Adaptive Multi-Rate">AMR-Narrowband</a>, which is high quality and robust against interference when used on full-rate channels, or less robust but still relatively high quality when used in good radio conditions on half-rate channel. </p> <div class="mw-heading mw-heading3"><h3 id="Subscriber_Identity_Module_(SIM)"><span id="Subscriber_Identity_Module_.28SIM.29"></span>Subscriber Identity Module (SIM)</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=12" title="Edit section: Subscriber Identity Module (SIM)"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Nano_Sim.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/a3/Nano_Sim.jpg/220px-Nano_Sim.jpg" decoding="async" width="220" height="146" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/a3/Nano_Sim.jpg/330px-Nano_Sim.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/a3/Nano_Sim.jpg/440px-Nano_Sim.jpg 2x" data-file-width="3553" data-file-height="2354" /></a><figcaption>A nano sim used in mobile phones</figcaption></figure> <p>One of the key features of GSM is the <a href="/wiki/Subscriber_Identity_Module" class="mw-redirect" title="Subscriber Identity Module">Subscriber Identity Module</a>, commonly known as a <b>SIM card</b>. The SIM is a detachable <a href="/wiki/Smart_card" title="Smart card">smart card</a><sup id="cite_ref-:0_2-1" class="reference"><a href="#cite_note-:0-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> containing a user's subscription information and phone book. This allows users to retain their information after switching handsets. Alternatively, users can change networks or network identities without switching handsets - simply by changing the SIM. </p> <div class="mw-heading mw-heading3"><h3 id="Phone_locking">Phone locking</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=13" title="Edit section: Phone locking"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Sometimes <a href="/wiki/Mobile_network_operator" title="Mobile network operator">mobile network operators</a> restrict handsets that they sell for exclusive use in their own network. This is called <a href="/wiki/SIM_lock" title="SIM lock">SIM locking</a> and is implemented by a software feature of the phone. A subscriber may usually contact the provider to remove the lock for a fee, utilize private services to remove the lock, or use software and websites to unlock the handset themselves. It is possible to hack past a phone locked by a network operator. </p><p>In some countries and regions (e.g. <a href="/wiki/Brazil" title="Brazil">Brazil</a> and <a href="/wiki/Germany" title="Germany">Germany</a>) all phones are sold unlocked due to the abundance of dual-SIM handsets and operators.<sup id="cite_ref-German_Unlock_26-0" class="reference"><a href="#cite_note-German_Unlock-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="GSM_security">GSM security</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=14" title="Edit section: GSM security"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>GSM was intended to be a secure wireless system. It has considered the user authentication using a <a href="/wiki/Pre-shared_key" title="Pre-shared key">pre-shared key</a> and <a href="/wiki/Challenge%E2%80%93response_authentication" title="Challenge–response authentication">challenge–response</a>, and over-the-air encryption. However, GSM is vulnerable to different types of attack, each of them aimed at a different part of the network.<sup id="cite_ref-27" class="reference"><a href="#cite_note-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> </p><p>Research findings indicate that GSM faces susceptibility to hacking by <a href="/wiki/Script_kiddie" title="Script kiddie">script kiddies</a>, a term referring to inexperienced individuals utilizing readily available hardware and software. The vulnerability arises from the accessibility of tools such as a DVB-T TV tuner, posing a threat to both mobile and network users. Despite the term "script kiddies" implying a lack of sophisticated skills, the consequences of their attacks on GSM can be severe, impacting the functionality of <a href="/wiki/Cellular_network" title="Cellular network">cellular networks</a>. Given that GSM continues to be the main source of cellular technology in numerous countries, its susceptibility to potential threats from malicious attacks is one that needs to be addressed.<sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> </p><p>The development of <a href="/wiki/Universal_Mobile_Telecommunications_System" class="mw-redirect" title="Universal Mobile Telecommunications System">UMTS</a> introduced an optional <a href="/wiki/Universal_Subscriber_Identity_Module" class="mw-redirect" title="Universal Subscriber Identity Module">Universal Subscriber Identity Module</a> (USIM), that uses a longer authentication key to give greater security, as well as mutually authenticating the network and the user, whereas GSM only authenticates the user to the network (and not vice versa). The security model therefore offers confidentiality and authentication, but limited authorization capabilities, and no <a href="/wiki/Non-repudiation" title="Non-repudiation">non-repudiation</a>. </p><p>GSM uses several cryptographic algorithms for security. The <a href="/wiki/A5/1" title="A5/1">A5/1</a>, <a href="/wiki/A5/2" title="A5/2">A5/2</a>, and <a href="/wiki/A5/3" class="mw-redirect" title="A5/3">A5/3</a> <a href="/wiki/Stream_cipher" title="Stream cipher">stream ciphers</a> are used for ensuring over-the-air voice privacy. A5/1 was developed first and is a stronger algorithm used within Europe and the United States; A5/2 is weaker and used in other countries. Serious weaknesses have been found in both algorithms: it is possible to break A5/2 in real-time with a <a href="/wiki/Ciphertext-only_attack" title="Ciphertext-only attack">ciphertext-only attack</a>, and in January 2007, The Hacker's Choice started the A5/1 cracking project with plans to use <a href="/wiki/FPGA" class="mw-redirect" title="FPGA">FPGAs</a> that allow A5/1 to be broken with a <a href="/wiki/Rainbow_table" title="Rainbow table">rainbow table</a> attack.<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> The system supports multiple algorithms so operators may replace that cipher with a stronger one. </p><p>Since 2000, different efforts have been made in order to crack the A5 encryption algorithms. Both A5/1 and A5/2 algorithms have been broken, and their <a href="/wiki/Cryptanalysis" title="Cryptanalysis">cryptanalysis</a> has been revealed in the literature. As an example, <a href="/wiki/Karsten_Nohl" title="Karsten Nohl">Karsten Nohl</a> developed a number of <a href="/wiki/Rainbow_table" title="Rainbow table">rainbow tables</a> (static values which reduce the time needed to carry out an attack) and have found new sources for <a href="/wiki/Known_plaintext_attack" class="mw-redirect" title="Known plaintext attack">known plaintext attacks</a>.<sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> He said that it is possible to build "a full GSM interceptor<span class="nowrap"> </span>... from open-source components" but that they had not done so because of legal concerns.<sup id="cite_ref-31" class="reference"><a href="#cite_note-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> Nohl claimed that he was able to intercept voice and text conversations by impersonating another user to listen to <a href="/wiki/Voicemail" title="Voicemail">voicemail</a>, make calls, or send text messages using a seven-year-old <a href="/wiki/Motorola" title="Motorola">Motorola</a> cellphone and decryption software available for free online.<sup id="cite_ref-32" class="reference"><a href="#cite_note-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> </p><p>GSM uses <a href="/wiki/General_Packet_Radio_Service" title="General Packet Radio Service">General Packet Radio Service</a> (GPRS) for data transmissions like browsing the web. The most commonly deployed GPRS ciphers were publicly broken in 2011.<sup id="cite_ref-33" class="reference"><a href="#cite_note-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p><p>The researchers revealed flaws in the commonly used GEA/1 and GEA/2 (standing for GPRS Encryption Algorithms 1 and 2) ciphers and published the open-source "gprsdecode" software for <a href="/wiki/Packet_analyzer" title="Packet analyzer">sniffing</a> GPRS networks. They also noted that some carriers do not encrypt the data (i.e., using GEA/0) in order to detect the use of traffic or protocols they do not like (e.g., <a href="/wiki/Skype" title="Skype">Skype</a>), leaving customers unprotected. GEA/3 seems to remain relatively hard to break and is said to be in use on some more modern networks. If used with <a href="/wiki/Subscriber_Identity_Module" class="mw-redirect" title="Subscriber Identity Module">USIM</a> to prevent connections to fake base stations and <a href="/wiki/Downgrade_attack" title="Downgrade attack">downgrade attacks</a>, users will be protected in the medium term, though migration to 128-bit GEA/4 is still recommended. </p><p>The first public cryptanalysis of GEA/1 and GEA/2 (also written GEA-1 and GEA-2) was done in 2021. It concluded that although using a 64-bit key, the GEA-1 algorithm actually provides only 40 bits of security, due to a relationship between two parts of the algorithm. The researchers found that this relationship was very unlikely to have happened if it was not intentional. This may have been done in order to satisfy European controls on export of cryptographic programs.<sup id="cite_ref-34" class="reference"><a href="#cite_note-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-35" class="reference"><a href="#cite_note-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Standards_information">Standards information</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=15" title="Edit section: Standards information"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The GSM systems and services are described in a set of standards governed by <a href="/wiki/ETSI" class="mw-redirect" title="ETSI">ETSI</a>, where a full list is maintained.<sup id="cite_ref-37" class="reference"><a href="#cite_note-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="GSM_open-source_software">GSM open-source software</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=16" title="Edit section: GSM open-source software"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Several <a href="/wiki/Open-source_software" title="Open-source software">open-source software</a> projects exist that provide certain GSM features:<sup id="cite_ref-38" class="reference"><a href="#cite_note-38"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup> </p> <ul><li>gsmd daemon by <a href="/wiki/Openmoko" title="Openmoko">Openmoko</a><sup id="cite_ref-39" class="reference"><a href="#cite_note-39"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/OpenBTS" title="OpenBTS">OpenBTS</a> develops a <a href="/wiki/Base_transceiver_station" title="Base transceiver station">Base transceiver station</a></li> <li><i>The GSM Software Project</i> aims to build a GSM analyzer for less than $1,000<sup id="cite_ref-40" class="reference"><a href="#cite_note-40"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup></li> <li><i><a href="/wiki/OsmocomBB" class="mw-redirect" title="OsmocomBB">OsmocomBB</a></i> developers intend to replace the proprietary baseband GSM stack with a free software implementation<sup id="cite_ref-41" class="reference"><a href="#cite_note-41"><span class="cite-bracket">[</span>41<span class="cite-bracket">]</span></a></sup></li> <li>YateBTS develops a <a href="/wiki/Base_transceiver_station" title="Base transceiver station">Base transceiver station</a><sup id="cite_ref-42" class="reference"><a href="#cite_note-42"><span class="cite-bracket">[</span>42<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading3"><h3 id="Issues_with_patents_and_open_source">Issues with patents and open source</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=17" title="Edit section: Issues with patents and open source"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Patents remain a problem for any open-source GSM implementation, because it is not possible for GNU or any other free software distributor to guarantee immunity from all lawsuits by the patent holders against the users. Furthermore, new features are being added to the standard all the time which means they have patent protection for a number of years.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (June 2010)">citation needed</span></a></i>]</sup> </p><p>The original GSM implementations from 1991 may now be entirely free of patent encumbrances, however patent freedom is not certain due to the United States' "first to invent" system that was in place until 2012. The "first to invent" system, coupled with "patent term adjustment" can extend the life of a U.S. patent far beyond 20 years from its priority date. It is unclear at this time whether <a href="/wiki/OpenBTS" title="OpenBTS">OpenBTS</a> will be able to implement features of that initial specification without limit. As patents subsequently expire, however, those features can be added into the open-source version. As of 2011<sup class="plainlinks noexcerpt noprint asof-tag update" style="display:none;"><a class="external text" href="https://en.wikipedia.org/w/index.php?title=GSM&action=edit">[update]</a></sup>, there have been no lawsuits against users of OpenBTS over GSM use.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (June 2010)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=18" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1184024115">.mw-parser-output .div-col{margin-top:0.3em;column-width:30em}.mw-parser-output .div-col-small{font-size:90%}.mw-parser-output .div-col-rules{column-rule:1px solid #aaa}.mw-parser-output .div-col dl,.mw-parser-output .div-col ol,.mw-parser-output .div-col ul{margin-top:0}.mw-parser-output .div-col li,.mw-parser-output .div-col dd{page-break-inside:avoid;break-inside:avoid-column}</style><div class="div-col" style="column-width: 30em;"> <ul><li><a href="/wiki/Cellular_network" title="Cellular network">Cellular network</a></li> <li><a href="/wiki/Enhanced_Data_Rates_for_GSM_Evolution" class="mw-redirect" title="Enhanced Data Rates for GSM Evolution">Enhanced Data Rates for GSM Evolution</a> (EDGE)</li> <li><a href="/wiki/Call_forwarding#Mobile_(cell)_phones" title="Call forwarding">GSM forwarding standard features codes</a> – list of call forward codes working with all operators and phones</li> <li><a href="/wiki/GSM_frequency_bands" title="GSM frequency bands">GSM frequency bands</a></li> <li><a href="/wiki/GSM_modem" title="GSM modem">GSM modem</a></li> <li><a href="/wiki/GSM_services" title="GSM services">GSM services</a> <ul><li><a href="/wiki/Cell_Broadcast" title="Cell Broadcast">Cell Broadcast</a></li> <li><a href="/wiki/GSM_localization" class="mw-redirect" title="GSM localization">GSM localization</a></li> <li><a href="/wiki/Multimedia_Messaging_Service" title="Multimedia Messaging Service">Multimedia Messaging Service</a> (MMS)</li> <li><a href="/wiki/NITZ" title="NITZ">NITZ</a> Network Identity and Time Zone</li> <li><a href="/wiki/Wireless_Application_Protocol" title="Wireless Application Protocol">Wireless Application Protocol</a> (WAP)</li></ul></li> <li><a href="/wiki/GSM-R" title="GSM-R">GSM-R</a> (GSM-Railway)</li> <li><a href="/wiki/Unstructured_Supplementary_Service_Data" title="Unstructured Supplementary Service Data">GSM USSD codes</a> – Unstructured Supplementary Service Data: list of all standard GSM codes for network and SIM related functions</li> <li><a href="/wiki/Handoff" class="mw-redirect" title="Handoff">Handoff</a></li> <li><a href="/wiki/High-Speed_Downlink_Packet_Access" class="mw-redirect" title="High-Speed Downlink Packet Access">High-Speed Downlink Packet Access</a> (HSDPA)</li> <li><a href="/wiki/International_Mobile_Equipment_Identity" title="International Mobile Equipment Identity">International Mobile Equipment Identity</a> (IMEI)</li> <li><a href="/wiki/International_Mobile_Subscriber_Identity" class="mw-redirect" title="International Mobile Subscriber Identity">International Mobile Subscriber Identity</a> (IMSI)</li> <li><a href="/wiki/LTE_(telecommunication)" title="LTE (telecommunication)">Long Term Evolution</a> (LTE)</li> <li><a href="/wiki/MSISDN" title="MSISDN">MSISDN</a> Mobile Subscriber ISDN Number</li> <li><a href="/wiki/Nordic_Mobile_Telephone" title="Nordic Mobile Telephone">Nordic Mobile Telephone</a> (NMT)</li> <li><a href="/wiki/ORFS" class="mw-redirect" title="ORFS">ORFS</a></li> <li><a href="/wiki/Personal_communications_network" title="Personal communications network">Personal communications network</a> (PCN)</li> <li><a href="/wiki/RTP_audio_video_profile" class="mw-redirect" title="RTP audio video profile">RTP audio video profile</a></li> <li><a href="/wiki/Network_simulation" title="Network simulation">Simulation of GSM networks</a></li> <li>Standards <ul><li><a href="/wiki/Comparison_of_mobile_phone_standards" title="Comparison of mobile phone standards">Comparison of mobile phone standards</a></li> <li><a href="/wiki/GEO-Mobile_Radio_Interface" title="GEO-Mobile Radio Interface">GEO-Mobile Radio Interface</a></li> <li><a href="/wiki/GSM_02.07" title="GSM 02.07">GSM 02.07</a> – Cellphone features</li> <li><a href="/wiki/GSM_03.48" title="GSM 03.48">GSM 03.48</a> – Security mechanisms for the SIM application toolkit</li> <li><a href="/wiki/Intelligent_Network" title="Intelligent Network">Intelligent Network</a></li> <li><a href="/wiki/Parlay_X" title="Parlay X">Parlay X</a></li> <li><a href="/wiki/RRLP" class="mw-redirect" title="RRLP">RRLP</a> – Radio Resource Location Protocol</li></ul></li> <li><a href="/wiki/Um_interface" title="Um interface">Um interface</a></li> <li><a href="/wiki/Visitors_Location_Register" class="mw-redirect" title="Visitors Location Register">Visitors Location Register</a> (VLR)</li></ul> </div> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=19" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-columns references-column-width" style="column-width: 30em;"> <ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFSauter,_Martin2013" class="citation web cs1">Sauter, Martin (21 November 2013). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160304202434/http://mobilesociety.typepad.com/mobile_life/2013/11/the-gsm-logo-the-mystery-of-the-4-dots-solved.html">"The GSM Logo: The Mystery of the 4 Dots Solved"</a>. Archived from <a rel="nofollow" class="external text" href="http://mobilesociety.typepad.com/mobile_life/2013/11/the-gsm-logo-the-mystery-of-the-4-dots-solved.html">the original</a> on 4 March 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">23 November</span> 2013</span>. <q>[...] here's what [Yngve Zetterstrom, rapporteur of the Marketing and Planning (MP) group of the MoU (Memorandum of Understanding group, later to become the GSM Association (GSMA)) in 1989] had to say to solve the mystery: '[The dots symbolize] three [clients] in the home network and one roaming client.' There you go, an answer from the prime source!</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=The+GSM+Logo%3A+The+Mystery+of+the+4+Dots+Solved&rft.date=2013-11-21&rft.au=Sauter%2C+Martin&rft_id=http%3A%2F%2Fmobilesociety.typepad.com%2Fmobile_life%2F2013%2F11%2Fthe-gsm-logo-the-mystery-of-the-4-dots-solved.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-:0-2"><span class="mw-cite-backlink">^ <a href="#cite_ref-:0_2-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-:0_2-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://trademarks.justia.com/877/03/gsm-87703883.html">"GSM BRANDS Trademark of GSM Sales LLC - Registration Number 5523328 - Serial Number 87703883 :: Justia Trademarks"</a>. <i>trademarks.justia.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">9 February</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=trademarks.justia.com&rft.atitle=GSM+BRANDS+Trademark+of+GSM+Sales+LLC+-+Registration+Number+5523328+-+Serial+Number+87703883+%3A%3A+Justia+Trademarks&rft_id=http%3A%2F%2Ftrademarks.justia.com%2F877%2F03%2Fgsm-87703883.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.electronics-notes.com/articles/connectivity/2g-gsm/audio-codecs-vocoders-amr-celp.php">"GSM Audio Codec: Vocoder: AMR, CELP etc .. » Electronics Notes"</a>. <i>www.electronics-notes.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">9 February</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.electronics-notes.com&rft.atitle=GSM+Audio+Codec%3A+Vocoder%3A+AMR%2C+CELP+etc+..+%C2%BB+Electronics+Notes&rft_id=https%3A%2F%2Fwww.electronics-notes.com%2Farticles%2Fconnectivity%2F2g-gsm%2Faudio-codecs-vocoders-amr-celp.php&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text">Anton A. Huurdeman, <a rel="nofollow" class="external text" href="https://books.google.com/books?id=SnjGRDVIUL4C&q=GSM+1992+finnish">The Worldwide History of Telecommunications</a>, John Wiley & Sons, 31 July 2003, page 529</span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20140208025938/http://www.4gamericas.org/index.cfm?fuseaction=page&sectionid=242">"GSM Global system for Mobile Communications"</a>. 4G Americas. Archived from <a rel="nofollow" class="external text" href="http://www.4gamericas.org/index.cfm?fuseaction=page&sectionid=242">the original</a> on 8 February 2014<span class="reference-accessdate">. Retrieved <span class="nowrap">22 March</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=GSM+Global+system+for+Mobile+Communications&rft.pub=4G+Americas&rft_id=http%3A%2F%2Fwww.4gamericas.org%2Findex.cfm%3Ffuseaction%3Dpage%26sectionid%3D242&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.cellular-news.com/index.html">"GSM (2nd Generation Mobiles)"</a>. <i>Engaging with Communications</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20230130070716/https://www.engagingwithcommunications.com/Technology/Mobiles/GSM/gsm.php">Archived</a> from the original on 30 January 2023<span class="reference-accessdate">. Retrieved <span class="nowrap">23 May</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Engaging+with+Communications&rft.atitle=GSM+%282nd+Generation+Mobiles%29&rft_id=http%3A%2F%2Fwww.cellular-news.com%2Findex.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-zdnet_birthday-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-zdnet_birthday_7-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLeader2007" class="citation web cs1">Leader (7 September 2007). <a rel="nofollow" class="external text" href="https://archive.today/20110505004052/http://www.zdnet.co.uk/news/mobile-devices/2007/09/07/happy-20th-birthday-gsm-39289154/">"Happy 20th Birthday, GSM"</a>. <i>zdnet.co.uk</i>. CBS Interactive. Archived from <a rel="nofollow" class="external text" href="http://www.zdnet.co.uk/news/mobile-devices/2007/09/07/happy-20th-birthday-gsm-39289154/">the original</a> on 5 May 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">5 May</span> 2011</span>. <q>Before GSM, Europe had a disastrous mishmash of national analogue standards in phones and TV, designed to protect national industries but instead creating fragmented markets vulnerable to big guns from abroad.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=zdnet.co.uk&rft.atitle=Happy+20th+Birthday%2C+GSM&rft.date=2007-09-07&rft.au=Leader&rft_id=http%3A%2F%2Fwww.zdnet.co.uk%2Fnews%2Fmobile-devices%2F2007%2F09%2F07%2Fhappy-20th-birthday-gsm-39289154%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-etsi_gsm-8"><span class="mw-cite-backlink">^ <a href="#cite_ref-etsi_gsm_8-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-etsi_gsm_8-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120211060002/http://www.etsi.org/WebSite/technologies/gsm.aspx">"GSM"</a>. <i>etsi.org</i>. European Telecommunications Standards Institute. 2011. Archived from <a rel="nofollow" class="external text" href="http://www.etsi.org/WebSite/Technologies/gsm.aspx">the original</a> on 11 February 2012<span class="reference-accessdate">. Retrieved <span class="nowrap">5 May</span> 2011</span>. <q>GSM was designed principally for voice telephony, but a range of bearer services was defined...allowing circuit-switched data connections at up to 9600 bits/s.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=etsi.org&rft.atitle=GSM&rft.date=2011&rft_id=http%3A%2F%2Fwww.etsi.org%2FWebSite%2FTechnologies%2Fgsm.aspx&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-gsmworld_history-9"><span class="mw-cite-backlink">^ <a href="#cite_ref-gsmworld_history_9-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-gsmworld_history_9-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-gsmworld_history_9-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-gsmworld_history_9-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-gsmworld_history_9-4"><sup><i><b>e</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110519093843/http://gsmworld.com/about-us/history.htm">"History"</a>. <i>gsmworld.com</i>. GSM Association. 2001. Archived from <a rel="nofollow" class="external text" href="http://www.gsmworld.com/about-us/history.htm">the original</a> on 19 May 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">5 May</span> 2011</span>. <q>1982 Groupe Speciale Mobile (GSM) is formed by the Confederation of European Posts and Telecommunications (CEPT) to design a pan-European mobile technology.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=gsmworld.com&rft.atitle=History&rft.date=2001&rft_id=http%3A%2F%2Fwww.gsmworld.com%2Fabout-us%2Fhistory.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-etsi_cellhist-10"><span class="mw-cite-backlink">^ <a href="#cite_ref-etsi_cellhist_10-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-etsi_cellhist_10-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120217044925/http://www.etsi.org/WebSite/Technologies/Cellularhistory.aspx">"Cellular History"</a>. <i>etsi.org</i>. European Telecommunications Standards Institute. 2011. Archived from <a rel="nofollow" class="external text" href="http://www.etsi.org/WebSite/Technologies/Cellularhistory.aspx">the original</a> on 17 February 2012<span class="reference-accessdate">. Retrieved <span class="nowrap">5 May</span> 2011</span>. <q>The task was entrusted to a committee known as Groupe Spécial Mobile (GSMTM), aided by a "permanent nucleus" of technical support personnel, based in Paris.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=etsi.org&rft.atitle=Cellular+History&rft.date=2011&rft_id=http%3A%2F%2Fwww.etsi.org%2FWebSite%2FTechnologies%2FCellularhistory.aspx&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.gsmhistory.com/created-gsm/">"Who created GSM?"</a>. Stephen Temple. 7 January 2007<span class="reference-accessdate">. Retrieved <span class="nowrap">7 April</span> 2013</span>. <q>Before GSM, Europe had a disastrous mishmash of national analogue standards in phones and TV, designed to protect national industries but instead creating fragmented markets vulnerable to big guns from abroad.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Who+created+GSM%3F&rft.pub=Stephen+Temple&rft.date=2007-01-07&rft_id=http%3A%2F%2Fwww.gsmhistory.com%2Fcreated-gsm%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.ieee-ukandireland.org/duke-of-cambridge-presents-maxwell-medals-to-gsm-developers/">"Duke of Cambridge Presents Maxwell Medals to GSM Developers"</a>. IEEE United Kingdom and Ireland Section. 1 September 2018<span class="reference-accessdate">. Retrieved <span class="nowrap">10 December</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Duke+of+Cambridge+Presents+Maxwell+Medals+to+GSM+Developers&rft.pub=IEEE+United+Kingdom+and+Ireland+Section&rft.date=2018-09-01&rft_id=https%3A%2F%2Fwww.ieee-ukandireland.org%2Fduke-of-cambridge-presents-maxwell-medals-to-gsm-developers%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110706064231/http://www.yle.fi/elavaarkisto/?s=s&g=1&ag=86&t=586&a=5126">"Maailman ensimmäinen GSM-puhelu"</a> [World's first GSM call]. <i>yle.fi</i>. Yelisradio OY. 22 February 2008. Archived from <a rel="nofollow" class="external text" href="http://www.yle.fi/elavaarkisto/?s=s&g=1&ag=86&t=586&a=5126">the original</a> on 6 July 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">5 May</span> 2011</span>. <q>Harri Holkeri made the first call on the Radiolinja (Elisa's subsidiary) network, at the opening ceremony in Helsinki on 07.01.1991.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=yle.fi&rft.atitle=Maailman+ensimm%C3%A4inen+GSM-puhelu&rft.date=2008-02-22&rft_id=http%3A%2F%2Fwww.yle.fi%2Felavaarkisto%2F%3Fs%3Ds%26g%3D1%26ag%3D86%26t%3D586%26a%3D5126&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.hs.fi/visio/art-2000008075194.html">"Ensimmäinen gsm-puhelu soitettiin 30 vuotta sitten"</a> [World's first GSM call was made 30 years ago]. <i>hs.fi</i>. 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Hän uskoo, että seuraava murros kestää ainakin 10 vuotta.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=hs.fi&rft.atitle=Ensimm%C3%A4inen+gsm-puhelu+soitettiin+30+vuotta+sitten&rft.date=2021-07-01&rft_id=https%3A%2F%2Fwww.hs.fi%2Fvisio%2Fart-2000008075194.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-gsma_stats-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-gsma_stats_15-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20100521013451/http://www.gsmworld.com/newsroom/market-data/market_data_summary.htm">"GSM World statistics"</a>. <i>gsmworld.com</i>. GSM Association. 2010. Archived from <a rel="nofollow" class="external text" href="http://www.gsmworld.com/newsroom/market-data/market_data_summary.htm">the original</a> on 21 May 2010<span class="reference-accessdate">. Retrieved <span class="nowrap">8 June</span> 2010</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=gsmworld.com&rft.atitle=GSM+World+statistics&rft.date=2010&rft_id=http%3A%2F%2Fwww.gsmworld.com%2Fnewsroom%2Fmarket-data%2Fmarket_data_summary.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20140330060902/http://www.etsi.org/technologies-clusters/technologies/mobile/gsm?highlight=YToxOntpOjA7czozOiJnc20iO30=">"Mobile technologies GSM"</a>. 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Retrieved <span class="nowrap">7 November</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Mobile+technologies+GSM&rft_id=http%3A%2F%2Fwww.etsi.org%2Ftechnologies-clusters%2Ftechnologies%2Fmobile%2Fgsm%3Fhighlight%3DYToxOntpOjA7czozOiJnc20iO30%3D&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMartin_Sauter2014" class="citation book cs1">Martin Sauter (23 June 2014). <i>From GSM to LTE-Advanced : An Introduction to Mobile Networks and Mobile Broadband</i> (Second ed.). 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Vol. 12697. pp. 155–183. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F978-3-030-77886-6_6">10.1007/978-3-030-77886-6_6</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-030-77885-9" title="Special:BookSources/978-3-030-77885-9"><bdi>978-3-030-77885-9</bdi></a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:235452714">235452714</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20210616151111/https://eprint.iacr.org/2021/819.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on 16 June 2021.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Cryptanalysis+of+the+GPRS+Encryption+Algorithms+GEA-1+and+GEA-2&rft.btitle=Advances+in+Cryptology+%E2%80%93+EUROCRYPT+2021&rft.series=Lecture+Notes+in+Computer+Science&rft.pages=155-183&rft.date=2021-06-18&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A235452714%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1007%2F978-3-030-77886-6_6&rft.isbn=978-3-030-77885-9&rft.au=Christof+Beierle&rft_id=https%3A%2F%2Feprint.iacr.org%2F2021%2F819.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-36"><span class="mw-cite-backlink"><b><a href="#cite_ref-36">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMatthew_Sparks2021" class="citation journal cs1">Matthew Sparks (17 June 2021). <a rel="nofollow" class="external text" href="https://www.newscientist.com/article/2281423-flaw-in-old-mobile-phone-encryption-code-could-be-used-for-snooping/">"Flaw in old mobile phone encryption code could be used for snooping"</a>. <i>New Scientist</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=New+Scientist&rft.atitle=Flaw+in+old+mobile+phone+encryption+code+could+be+used+for+snooping&rft.date=2021-06-17&rft.au=Matthew+Sparks&rft_id=https%3A%2F%2Fwww.newscientist.com%2Farticle%2F2281423-flaw-in-old-mobile-phone-encryption-code-could-be-used-for-snooping%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-37">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://webapp.etsi.org/key/key.asp?full_list=y">"GSM UMTS 3GPP Numbering Cross Reference"</a>. ETSI<span class="reference-accessdate">. Retrieved <span class="nowrap">30 December</span> 2009</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=GSM+UMTS+3GPP+Numbering+Cross+Reference&rft.pub=ETSI&rft_id=http%3A%2F%2Fwebapp.etsi.org%2Fkey%2Fkey.asp%3Ffull_list%3Dy&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-38"><span class="mw-cite-backlink"><b><a href="#cite_ref-38">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDonaldFavour2016" class="citation journal cs1">Donald, Ene; Favour, Osagie Nosa (October 2016). "Analysing GSM Insecurity". <i>International Journal of Research & Scientific Innovation</i>. <b>3</b> (10): 10. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/2321-2705">2321-2705</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:212468467">212468467</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=International+Journal+of+Research+%26+Scientific+Innovation&rft.atitle=Analysing+GSM+Insecurity&rft.volume=3&rft.issue=10&rft.pages=10&rft.date=2016-10&rft.issn=2321-2705&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A212468467%23id-name%3DS2CID&rft.aulast=Donald&rft.aufirst=Ene&rft.au=Favour%2C+Osagie+Nosa&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-39"><span class="mw-cite-backlink"><b><a href="#cite_ref-39">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://wiki.openmoko.org/wiki/Gsmd">"Gsmd – Openmoko"</a>. Wiki.openmoko.org. 8 February 2010<span class="reference-accessdate">. Retrieved <span class="nowrap">22 April</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Gsmd+%E2%80%93+Openmoko&rft.pub=Wiki.openmoko.org&rft.date=2010-02-08&rft_id=http%3A%2F%2Fwiki.openmoko.org%2Fwiki%2FGsmd&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-40"><span class="mw-cite-backlink"><b><a href="#cite_ref-40">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20100815011913/http://wiki.thc.org/">"The Hacker's Choice Wiki"</a>. Archived from <a rel="nofollow" class="external text" href="http://wiki.thc.org/">the original</a> on 15 August 2010<span class="reference-accessdate">. Retrieved <span class="nowrap">30 August</span> 2010</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=The+Hacker%27s+Choice+Wiki&rft_id=http%3A%2F%2Fwiki.thc.org%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-41"><span class="mw-cite-backlink"><b><a href="#cite_ref-41">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110226120714/http://bb.osmocom.org/trac/">"OsmocomBB"</a>. Bb.osmocom.org. Archived from <a rel="nofollow" class="external text" href="http://bb.osmocom.org/trac">the original</a> on 26 February 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">22 April</span> 2010</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=OsmocomBB&rft.pub=Bb.osmocom.org&rft_id=http%3A%2F%2Fbb.osmocom.org%2Ftrac&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> <li id="cite_note-42"><span class="mw-cite-backlink"><b><a href="#cite_ref-42">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.yatebts.com">"YateBTS"</a>. Legba Inc<span class="reference-accessdate">. Retrieved <span class="nowrap">30 October</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=YateBTS&rft.pub=Legba+Inc.&rft_id=http%3A%2F%2Fwww.yatebts.com&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=20" title="Edit section: Further reading"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRedlWeberOliphant1995" class="citation book cs1">Redl, Siegmund M.; Weber, Matthias K.; Oliphant, Malcolm W (February 1995). <i>An Introduction to GSM</i>. Artech House. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-89006-785-7" title="Special:BookSources/978-0-89006-785-7"><bdi>978-0-89006-785-7</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=An+Introduction+to+GSM&rft.pub=Artech+House&rft.date=1995-02&rft.isbn=978-0-89006-785-7&rft.aulast=Redl&rft.aufirst=Siegmund+M.&rft.au=Weber%2C+Matthias+K.&rft.au=Oliphant%2C+Malcolm+W&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRedlWeberOliphant1998" class="citation book cs1">Redl, Siegmund M.; Weber, Matthias K.; Oliphant, Malcolm W (April 1998). <i>GSM and Personal Communications Handbook</i>. Artech House Mobile Communications Library. Artech House. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-89006-957-8" title="Special:BookSources/978-0-89006-957-8"><bdi>978-0-89006-957-8</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=GSM+and+Personal+Communications+Handbook&rft.series=Artech+House+Mobile+Communications+Library&rft.pub=Artech+House&rft.date=1998-04&rft.isbn=978-0-89006-957-8&rft.aulast=Redl&rft.aufirst=Siegmund+M.&rft.au=Weber%2C+Matthias+K.&rft.au=Oliphant%2C+Malcolm+W&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHillebrand2001" class="citation book cs1">Hillebrand, Friedhelm, ed. (December 2001). <i>GSM and UMTS, The Creation of Global Mobile Communications</i>. John Wiley & Sons. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-470-84322-2" title="Special:BookSources/978-0-470-84322-2"><bdi>978-0-470-84322-2</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=GSM+and+UMTS%2C+The+Creation+of+Global+Mobile+Communications&rft.pub=John+Wiley+%26+Sons&rft.date=2001-12&rft.isbn=978-0-470-84322-2&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMoulyPautet2002" class="citation book cs1">Mouly, Michel; Pautet, Marie-Bernardette (June 2002). <i>The GSM System for Mobile Communications</i>. Telecom Publishing. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-945592-15-0" title="Special:BookSources/978-0-945592-15-0"><bdi>978-0-945592-15-0</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+GSM+System+for+Mobile+Communications&rft.pub=Telecom+Publishing&rft.date=2002-06&rft.isbn=978-0-945592-15-0&rft.aulast=Mouly&rft.aufirst=Michel&rft.au=Pautet%2C+Marie-Bernardette&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSalgues1997" class="citation book cs1">Salgues, Salgues B. (April 1997). <i>Les télécoms mobiles GSM DCS</i>. Hermes (2nd ed.). Hermes Sciences Publications. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-2866016067" title="Special:BookSources/978-2866016067"><bdi>978-2866016067</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Les+t%C3%A9l%C3%A9coms+mobiles+GSM+DCS&rft.series=Hermes&rft.edition=2nd&rft.pub=Hermes+Sciences+Publications&rft.date=1997-04&rft.isbn=978-2866016067&rft.aulast=Salgues&rft.aufirst=Salgues+B.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGSM" class="Z3988"></span></li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=GSM&action=edit&section=21" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png" decoding="async" width="30" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span></div> <div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:GSM_Standard" class="extiw" title="commons:Category:GSM Standard">GSM Standard</a></span>.</div></div> </div> <ul><li><a rel="nofollow" class="external text" href="https://www.gsma.com">GSM Association</a>—Official industry trade group representing GSM network operators worldwide</li> <li><a rel="nofollow" class="external text" href="https://www.3gpp.org">3GPP</a>—3G GSM standards development group</li> <li><a rel="nofollow" class="external text" href="http://lte-3gpp.info">LTE-3GPP.info: online GSM messages decoder fully supporting all 3GPP releases from early GSM to latest 5G</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist 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href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Cellular_network_standards" title="Template:Cellular network standards"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Cellular_network_standards" title="Template talk:Cellular network standards"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Cellular_network_standards" title="Special:EditPage/Template:Cellular network standards"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Cellular_network_standards" style="font-size:114%;margin:0 4em"><a href="/wiki/Cellular_network" title="Cellular network">Cellular network</a> standards</div></th></tr><tr><td class="navbox-abovebelow" colspan="2"><div><a href="/wiki/List_of_mobile_phone_generations" class="mw-redirect" title="List of mobile phone generations">List of mobile phone generations</a></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Mobile_radio_telephone" title="Mobile radio telephone">0G</a> <a href="/wiki/Radiotelephone" title="Radiotelephone">radio telephones</a> (1946)</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Mobile_Telephone_Service" title="Mobile Telephone Service">MTS</a></li> <li><a href="/wiki/Improved_Mobile_Telephone_Service" title="Improved Mobile Telephone Service">IMTS</a></li> <li><a href="/wiki/Altai_(mobile_telephone_system)" title="Altai (mobile telephone system)">Altai</a></li> <li><a href="/wiki/OLT_(mobile_network)" title="OLT (mobile network)">OLT</a></li> <li><a href="/wiki/MTD_(mobile_network)" title="MTD (mobile network)">MTA - MTB - MTC - MTD</a></li> <li><a href="/w/index.php?title=Mobile_TeleSeratout&action=edit&redlink=1" class="new" title="Mobile TeleSeratout (page does not exist)">Mobile TeleSeratout</a></li> <li><a href="/wiki/Advanced_Mobile_Telephone_System" title="Advanced Mobile Telephone System">AMTS</a></li> <li><a href="/wiki/Autotel" title="Autotel">Autotel (PALM)</a></li> <li><a href="/wiki/Autoradiopuhelin" title="Autoradiopuhelin">ARP</a></li> <li><a href="/wiki/B-Netz" title="B-Netz">B-Netz</a></li> <li><a href="/wiki/AMR_radiotelephone_network_(Czechoslovakia)" title="AMR radiotelephone network (Czechoslovakia)">AMR</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/1G" title="1G">1G</a> (1979)</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Advanced_Mobile_Phone_System" title="Advanced Mobile Phone System">AMPS</a> family</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Advanced_Mobile_Phone_System" title="Advanced Mobile Phone System">AMPS - N-AMPS</a></li> <li><a href="/wiki/Total_Access_Communication_System" title="Total Access Communication System">TACS - ETACS</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">Other</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Nordic_Mobile_Telephone" title="Nordic Mobile Telephone">NMT</a></li> <li><a href="/wiki/C-Netz" title="C-Netz">C-450</a></li> <li><a href="/wiki/Hicap" title="Hicap">Hicap</a></li> <li><a href="/wiki/Mobitex" title="Mobitex">Mobitex</a></li> <li><a href="/wiki/DataTAC" title="DataTAC">DataTAC</a></li> <li><a href="/wiki/CT1" title="CT1">CT1</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/2G" title="2G">2G</a> (1991)</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em"><a class="mw-selflink selflink">GSM</a>/<a href="/wiki/3GPP" title="3GPP">3GPP</a> family</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a class="mw-selflink selflink">GSM</a></li> <li><a href="/wiki/Circuit_Switched_Data" title="Circuit Switched Data">CSD - HSCSD</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/3rd_Generation_Partnership_Project_2" title="3rd Generation Partnership Project 2">3GPP2</a> family</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/CdmaOne" title="CdmaOne">cdmaOne (IS-95)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Advanced_Mobile_Phone_System" title="Advanced Mobile Phone System">AMPS</a> family</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Digital_AMPS" title="Digital AMPS">D-AMPS (IS-54 and IS-136)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">Other</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cellular_digital_packet_data" title="Cellular digital packet data">CDPD</a></li> <li><a href="/wiki/IDEN" title="IDEN">iDEN</a></li> <li><a href="/wiki/Personal_Digital_Cellular" title="Personal Digital Cellular">PDC</a></li> <li><a href="/wiki/Personal_Handy-phone_System" title="Personal Handy-phone System">PHS</a></li> <li><a href="/wiki/CT2" title="CT2">CT2</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/2G#Evolution" title="2G">2G transitional<br />(2.5G, 2.75G, 2.9G)</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em"><a class="mw-selflink selflink">GSM</a>/3GPP family</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/General_Packet_Radio_Service" title="General Packet Radio Service">GPRS</a></li> <li><a href="/wiki/Enhanced_Data_rates_for_GSM_Evolution" title="Enhanced Data rates for GSM Evolution">EDGE/EGPRS - Evolved EDGE</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">3GPP2 family</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/CDMA2000#1X" title="CDMA2000">CDMA2000 1X</a> (TIA/EIA/IS-2000)</li> <li><a href="/wiki/CDMA2000#1X_Advanced" title="CDMA2000">CDMA2000 1X Advanced</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">Other</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/WiDEN" class="mw-redirect" title="WiDEN">WiDEN</a></li> <li><a href="/wiki/Digital_enhanced_cordless_telecommunications" class="mw-redirect" title="Digital enhanced cordless telecommunications">DECT</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/3G" title="3G">3G</a> (1998)<br /><a href="/wiki/IMT-2000" title="IMT-2000">IMT-2000</a> (2001)</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em">3GPP family</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/UMTS" title="UMTS">UMTS</a> <ul><li><a href="/wiki/W-CDMA" class="mw-redirect" title="W-CDMA">UTRA-FDD / W-CDMA</a> <ul><li><a href="/wiki/Freedom_of_Mobile_Multimedia_Access" title="Freedom of Mobile Multimedia Access">FOMA</a></li></ul></li> <li><a href="/wiki/TD-SCDMA" class="mw-redirect" title="TD-SCDMA">UTRA-TDD LCR / TD-SCDMA</a></li> <li><a href="/wiki/TD-CDMA" class="mw-redirect" title="TD-CDMA">UTRA-TDD HCR / TD-CDMA</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">3GPP2 family</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Evolution-Data_Optimized" title="Evolution-Data Optimized">CDMA2000 1xEV-DO Release 0</a> (TIA/IS-856)</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/3G#Evolution" title="3G">3G transitional<br />(3.5G, 3.75G, 3.9G)</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em">3GPP family</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/High_Speed_Packet_Access" title="High Speed Packet Access">HSPA</a> <ul><li><a href="/wiki/High_Speed_Downlink_Packet_Access" class="mw-redirect" title="High Speed Downlink Packet Access">HSDPA</a></li> <li><a href="/wiki/High_Speed_Uplink_Packet_Access" class="mw-redirect" title="High Speed Uplink Packet Access">HSUPA</a></li></ul></li> <li><a href="/wiki/Evolved_High_Speed_Packet_Access" title="Evolved High Speed Packet Access">HSPA+</a> <ul><li><a href="/wiki/DC-HSDPA" class="mw-redirect" title="DC-HSDPA">DC-HSDPA</a></li></ul></li> <li><a href="/wiki/LTE_(telecommunication)" title="LTE (telecommunication)">LTE</a> (<a href="/wiki/E-UTRA" title="E-UTRA">E-UTRA</a>)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">3GPP2 family</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li>CDMA2000 <a href="/wiki/Evolution-Data_Optimized" title="Evolution-Data Optimized">1xEV-DO Revision A</a> (TIA/EIA/IS-856-A)</li> <li><a href="/wiki/Evolution-Data_Optimized" title="Evolution-Data Optimized">EV-DO Revision B</a> (TIA/EIA/IS-856-B)</li> <li><a href="/wiki/Evolution-Data_Optimized" title="Evolution-Data Optimized">EV-DO Revision C</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/Institute_of_Electrical_and_Electronics_Engineers" title="Institute of Electrical and Electronics Engineers">IEEE</a> family</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/WiMAX" title="WiMAX">Mobile WiMAX</a> <ul><li><a href="/wiki/IEEE_802.16" title="IEEE 802.16">IEEE 802.16e</a></li></ul></li> <li><a href="/wiki/Orthogonal_frequency-division_multiplexing#FLASH-OFDM" title="Orthogonal frequency-division multiplexing">Flash-OFDM</a></li> <li><a href="/wiki/IEEE_802.20" title="IEEE 802.20">iBurst (IEEE 802.20)</a></li> <li><a href="/wiki/WiBro" title="WiBro">WiBro</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em"><a href="/wiki/ETSI" class="mw-redirect" title="ETSI">ETSI</a> family</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/HiperMAN" title="HiperMAN">HiperMAN</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/4G" title="4G">4G</a> (2009)<br /><a href="/wiki/IMT_Advanced" title="IMT Advanced">IMT Advanced</a> (2013)</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em">3GPP family</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/LTE_Advanced" title="LTE Advanced">LTE Advanced</a> (<a href="/wiki/E-UTRA" title="E-UTRA">E-UTRA</a>)</li> <li><a href="/wiki/LTE_Advanced_Pro" class="mw-redirect" title="LTE Advanced Pro">LTE Advanced Pro</a> (4.5G/4.9G)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">IEEE family</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/WiMAX" title="WiMAX">WiMAX</a> (<a href="/wiki/IEEE_802.16" title="IEEE 802.16">IEEE 802.16m</a>) <ul><li>WiMax 2.1</li> <li><a href="/wiki/WiBro" title="WiBro">WiBro</a></li></ul></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/5G" title="5G">5G</a> (2018)<br /><a href="/wiki/IMT-2020" title="IMT-2020">IMT-2020</a> (2021)</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10em">3GPP family</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/5G_NR" title="5G NR">5G NR</a></li> <li><a href="/wiki/5G-Advanced" class="mw-redirect" title="5G-Advanced">5G-Advanced</a> (5.5G)</li> <li><a href="/w/index.php?title=NR-IIoT&action=edit&redlink=1" class="new" title="NR-IIoT (page does not exist)">NR-IIoT</a></li> <li><a href="/wiki/LTE-M" title="LTE-M">LTE-M</a></li> <li><a href="/wiki/Narrowband_IoT" title="Narrowband IoT">NB-IoT</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10em">Other</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/w/index.php?title=DECT-5G&action=edit&redlink=1" class="new" title="DECT-5G (page does not exist)">DECT-5G</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related articles</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cellular_network" title="Cellular network">Cellular networks</a></li> <li><a href="/wiki/Mobile_telephony" title="Mobile telephony">Mobile telephony</a></li> <li><a href="/wiki/History_of_mobile_phones" title="History of mobile phones">History</a></li> <li><a href="/wiki/Comparison_of_mobile_phone_standards" title="Comparison of mobile phone standards">Comparison of standards</a></li> <li><a href="/wiki/Channel_access_method" title="Channel access method">Channel access methods</a> <ul><li><a href="/wiki/Frequency-division_multiple_access" title="Frequency-division multiple access">FDMA</a> <ul><li><a href="/wiki/Orthogonal_frequency-division_multiple_access" title="Orthogonal frequency-division multiple access">OFDMA</a></li></ul></li> <li><a href="/wiki/Time-division_multiple_access" title="Time-division multiple access">TDMA</a> <ul><li><a href="/wiki/Self-organized_time-division_multiple_access" title="Self-organized time-division multiple access">STDMA</a></li></ul></li> <li><a href="/wiki/Spread_spectrum" title="Spread spectrum">SSMA</a> <ul><li><a href="/wiki/Code-division_multiple_access" title="Code-division multiple access">CDMA</a></li></ul></li> <li><a href="/wiki/Space-division_multiple_access" title="Space-division multiple access">SDMA</a></li></ul></li> <li><a href="/wiki/Spectral_efficiency#Comparison_table" title="Spectral efficiency">Spectral efficiency comparison table</a></li> <li><a href="/wiki/Cellular_frequencies" title="Cellular frequencies">Frequency bands</a> <ul><li><a href="/wiki/GSM_frequency_bands" title="GSM frequency bands">GSM</a></li> <li><a href="/wiki/UMTS_frequency_bands" title="UMTS frequency bands">UMTS</a></li> <li><a href="/wiki/LTE_frequency_bands" title="LTE frequency bands">LTE</a></li> <li><a href="/wiki/5G_NR_frequency_bands" title="5G NR frequency bands">5G NR</a></li> <li><a href="/wiki/CDMA_frequency_bands" title="CDMA frequency bands">CDMA</a></li></ul></li> <li><a href="/wiki/Mobile_broadband" title="Mobile broadband">Mobile broadband</a></li> <li><a href="/wiki/Multimedia_Broadcast_Multicast_Service" title="Multimedia Broadcast Multicast Service">Multimedia Broadcast Multicast Service</a></li> <li><a href="/wiki/Next_Generation_Mobile_Networks" title="Next Generation Mobile Networks">NGMN Alliance</a></li> <li><a href="/wiki/Push-to-talk" title="Push-to-talk">Push-to-talk</a></li> <li><a href="/wiki/MIMO" title="MIMO">MIMO</a></li> <li><a href="/wiki/IP_Multimedia_Subsystem" title="IP Multimedia Subsystem">IMS</a> <ul><li><a href="/wiki/Voice_over_LTE" title="Voice over LTE">VoLTE</a></li> <li><a href="/wiki/Video_over_LTE" title="Video over LTE">ViLTE</a></li> <li><a href="/wiki/Voice_over_NR" title="Voice over NR">VoNR</a></li> <li><a href="/w/index.php?title=Video_over_NR&action=edit&redlink=1" class="new" title="Video over NR (page does not exist)">ViNR</a></li> <li><a href="/wiki/Generic_Access_Network" class="mw-redirect" title="Generic Access Network">Wi-Fi Calling</a></li></ul></li> <li><a href="/wiki/Osmocom" title="Osmocom">Osmocom</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div><span class="nowrap"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4e/Telecom-icon.svg/28px-Telecom-icon.svg.png" decoding="async" width="28" height="28" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4e/Telecom-icon.svg/42px-Telecom-icon.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4e/Telecom-icon.svg/56px-Telecom-icon.svg.png 2x" data-file-width="500" data-file-height="500" /></span></span> </span><a href="/wiki/Portal:Telecommunication" title="Portal:Telecommunication">Telecommunication portal</a>   <span class="nowrap"><span class="noviewer" typeof="mw:File"><span><img alt="telephone icon" src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Telephone_icon_blue_gradient.svg/28px-Telephone_icon_blue_gradient.svg.png" decoding="async" width="28" height="28" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Telephone_icon_blue_gradient.svg/42px-Telephone_icon_blue_gradient.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Telephone_icon_blue_gradient.svg/56px-Telephone_icon_blue_gradient.svg.png 2x" data-file-width="722" data-file-height="722" /></span></span> </span><a href="/wiki/Portal:Telephones" title="Portal:Telephones">Telephones portal</a></div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Channel_access_methods_and_media_access_control" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Channel_access_methods" title="Template:Channel access methods"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Channel_access_methods" title="Template talk:Channel access methods"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Channel_access_methods" title="Special:EditPage/Template:Channel access methods"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Channel_access_methods_and_media_access_control" style="font-size:114%;margin:0 4em"><a href="/wiki/Channel_access_method" title="Channel access method">Channel access methods</a> and <a href="/wiki/Medium_access_control" title="Medium access control">media access control</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Circuit_switching" title="Circuit switching">Channel-based</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Frequency-division_multiple_access" title="Frequency-division multiple access">FDMA</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Frequency-division_multiplexing" title="Frequency-division multiplexing">FDM</a> <ul><li><a href="/wiki/Orthogonal_frequency-division_multiple_access" title="Orthogonal frequency-division multiple access">OFDMA</a></li> <li><a href="/wiki/Single-carrier_FDMA" title="Single-carrier FDMA">SC-FDMA</a></li></ul></li> <li><a href="/wiki/Wavelength-division_multiplexing" title="Wavelength-division multiplexing">WDM</a> <ul><li><a href="/wiki/Wavelength-division_multiple_access" class="mw-redirect" title="Wavelength-division multiple access">WDMA</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Time-division_multiple_access" title="Time-division multiple access">TDMA</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Multi-frequency_time-division_multiple_access" title="Multi-frequency time-division multiple access">MF-TDMA</a></li> <li><a href="/wiki/Self-organized_time-division_multiple_access" title="Self-organized time-division multiple access">STDMA</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Code-division_multiple_access" title="Code-division multiple access">CDMA</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/W-CDMA" class="mw-redirect" title="W-CDMA">W-CDMA</a></li> <li><a href="/wiki/TD-CDMA" class="mw-redirect" title="TD-CDMA">TD-CDMA</a></li> <li><a href="/wiki/TD-SCDMA" class="mw-redirect" title="TD-SCDMA">TD-SCDMA</a></li> <li><a href="/wiki/Direct-sequence_spread_spectrum" title="Direct-sequence spread spectrum">DS-CDMA</a></li> <li><a href="/wiki/Frequency-hopping_spread_spectrum" title="Frequency-hopping spread spectrum">FH-CDMA</a></li> <li><a href="/wiki/Multi-carrier_code-division_multiple_access" title="Multi-carrier code-division multiple access">MC-CDMA</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Space-division_multiple_access" title="Space-division multiple access">SDMA</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/IBurst" class="mw-redirect" title="IBurst">HC-SDMA</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Polarization-division_multiple_access" title="Polarization-division multiple access">PDMA</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li class="mw-empty-elt"></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Pulse-address_multiple_access" title="Pulse-address multiple access">PAMA</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li class="mw-empty-elt"></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Packet_switching" title="Packet switching">Packet-based</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Contention_(telecommunications)" title="Contention (telecommunications)">Collision recovery</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ALOHAnet#The_ALOHA_protocol" title="ALOHAnet">ALOHA</a></li> <li><a href="/wiki/ALOHAnet" title="ALOHAnet">Slotted ALOHA</a></li> <li><a href="/wiki/Reservation_ALOHA" class="mw-redirect" title="Reservation ALOHA">R-ALOHA</a></li> <li><a href="/wiki/AX.25" title="AX.25">AX.25</a></li> <li><a href="/wiki/Carrier-sense_multiple_access_with_collision_detection" title="Carrier-sense multiple access with collision detection">CSMA/CD</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Contention_(telecommunications)" title="Contention (telecommunications)">Collision avoidance</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Multiple_Access_with_Collision_Avoidance" class="mw-redirect" title="Multiple Access with Collision Avoidance">MACA</a></li> <li><a href="/wiki/Multiple_Access_with_Collision_Avoidance_for_Wireless" title="Multiple Access with Collision Avoidance for Wireless">MACAW</a></li> <li><a href="/wiki/Carrier-sense_multiple_access" title="Carrier-sense multiple access">CSMA</a></li> <li><a href="/wiki/Carrier-sense_multiple_access_with_collision_avoidance" title="Carrier-sense multiple access with collision avoidance">CSMA/CA</a></li> <li><a href="/wiki/Distributed_coordination_function" title="Distributed coordination function">DCF</a></li> <li><a href="/wiki/Point_coordination_function" title="Point coordination function">PCF</a></li> <li><a href="/wiki/IEEE_802.11e-2005#802.11e_MAC_protocol_operation" title="IEEE 802.11e-2005">HCF</a></li> <li><a href="/wiki/CSMA/CARP" class="mw-redirect" title="CSMA/CARP">CSMA/CARP</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Collision_domain" title="Collision domain">Collision-free</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Token_Ring" title="Token Ring">Token Ring</a></li> <li><a href="/wiki/Token_bus_network" title="Token bus network">Token bus</a></li> <li><a href="/wiki/Mobile_Slotted_Aloha" title="Mobile Slotted Aloha">MS-ALOHA</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Delay and disruption tolerant</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Mobile_ad_hoc_network" class="mw-redirect" title="Mobile ad hoc network">MANET</a></li> <li><a href="/wiki/Vehicular_ad-hoc_network" class="mw-redirect" title="Vehicular ad-hoc network">VANET</a></li> <li><a href="/wiki/Delay-tolerant_networking" title="Delay-tolerant networking">DTN</a></li> <li><a href="/wiki/Dynamic_Source_Routing" title="Dynamic Source Routing">Dynamic Source Routing</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Duplex_(telecommunications)" title="Duplex (telecommunications)">Duplexing methods</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Duplex_(telecommunications)#Time-division_duplexing" title="Duplex (telecommunications)">TDD</a></li> <li><a href="/wiki/Duplex_(telecommunications)#Frequency-division_duplexing" title="Duplex (telecommunications)">FDD</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Telecommunications" style="padding:3px"><table class="nowraplinks hlist mw-collapsible mw-collapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Telecommunications" title="Template:Telecommunications"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Telecommunications" title="Template talk:Telecommunications"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Telecommunications" title="Special:EditPage/Template:Telecommunications"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Telecommunications" style="font-size:114%;margin:0 4em"><a href="/wiki/Telecommunications" title="Telecommunications">Telecommunications</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/History_of_telecommunication" title="History of telecommunication">History</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Beacon#For_defensive_communications" title="Beacon">Beacon</a></li> <li><a href="/wiki/History_of_broadcasting" title="History of broadcasting">Broadcasting</a></li> <li><a href="/wiki/Cable_protection_system" title="Cable protection system">Cable protection system</a></li> <li><a href="/wiki/Cable_television" title="Cable television">Cable TV</a></li> <li><a href="/wiki/Communications_satellite#History" title="Communications satellite">Communications satellite</a></li> <li><a href="/wiki/Computer_network#History" title="Computer network">Computer network</a></li> <li><a href="/wiki/Data_compression" title="Data compression">Data compression</a> <ul><li><a href="/wiki/Audio_coding_format" title="Audio coding format">audio</a></li> <li><a href="/wiki/Discrete_cosine_transform" title="Discrete cosine transform">DCT</a></li> <li><a href="/wiki/Image_compression" title="Image compression">image</a></li> <li><a href="/wiki/Video_coding_format" title="Video coding format">video</a></li></ul></li> <li><a href="/wiki/Digital_media" title="Digital media">Digital media</a> <ul><li><a href="/wiki/Internet_video" title="Internet video">Internet video</a></li> <li><a href="/wiki/Online_video_platform" title="Online video platform">online video platform</a></li> <li><a href="/wiki/Social_media" title="Social media">social media</a></li> <li><a href="/wiki/Streaming_media" title="Streaming media">streaming</a></li></ul></li> <li><a href="/wiki/Drums_in_communication" title="Drums in communication">Drums</a></li> <li><a href="/wiki/Edholm%27s_law" title="Edholm's law">Edholm's law</a></li> <li><a href="/wiki/Electrical_telegraph#History" title="Electrical telegraph">Electrical telegraph</a></li> <li><a href="/wiki/Fax#History" title="Fax">Fax</a></li> <li><a href="/wiki/Heliograph#History" title="Heliograph">Heliographs</a></li> <li><a href="/wiki/Hydraulic_telegraph#Greek_hydraulic_semaphore_system" title="Hydraulic telegraph">Hydraulic telegraph</a></li> <li><a href="/wiki/Information_Age" title="Information Age">Information Age</a></li> <li><a href="/wiki/Information_revolution" class="mw-redirect" title="Information revolution">Information revolution</a></li> <li><a href="/wiki/History_of_the_Internet" title="History of the Internet">Internet</a></li> <li><a href="/wiki/Mass_media#History" title="Mass media">Mass media</a></li> <li><a href="/wiki/History_of_mobile_phones" title="History of mobile phones">Mobile phone</a> <ul><li><a href="/wiki/Smartphone" title="Smartphone">Smartphone</a></li></ul></li> <li><a href="/wiki/Optical_communication" title="Optical communication">Optical telecommunication</a></li> <li><a href="/wiki/Optical_telegraph" title="Optical telegraph">Optical telegraphy</a></li> <li><a href="/wiki/Pager" title="Pager">Pager</a></li> <li><a href="/wiki/Photophone" title="Photophone">Photophone</a></li> <li><a href="/wiki/History_of_prepaid_mobile_phones" title="History of prepaid mobile phones">Prepaid mobile phone</a></li> <li><a href="/wiki/History_of_radio" title="History of radio">Radio</a></li> <li><a href="/wiki/Radiotelephone" title="Radiotelephone">Radiotelephone</a></li> <li><a href="/wiki/Communications_satellite" title="Communications satellite">Satellite communications</a></li> <li><a href="/wiki/Semaphore" title="Semaphore">Semaphore</a> <ul><li><a href="/wiki/Phryctoria" title="Phryctoria">Phryctoria</a></li></ul></li> <li><a href="/wiki/Semiconductor" title="Semiconductor">Semiconductor</a> <ul><li><a href="/wiki/Semiconductor_device" title="Semiconductor device">device</a></li> <li><a href="/wiki/MOSFET" title="MOSFET">MOSFET</a></li> <li><a href="/wiki/History_of_the_transistor" title="History of the transistor">transistor</a></li></ul></li> <li><a href="/wiki/Smoke_signal" title="Smoke signal">Smoke signals</a></li> <li><a href="/wiki/History_of_telecommunication" title="History of telecommunication">Telecommunications history</a></li> <li><a href="/wiki/Telautograph" title="Telautograph">Telautograph</a></li> <li><a href="/wiki/Telegraphy" title="Telegraphy">Telegraphy</a></li> <li><a href="/wiki/Teleprinter" title="Teleprinter">Teleprinter</a> (teletype)</li> <li><a href="/wiki/History_of_the_telephone" title="History of the telephone">Telephone</a></li> <li><i><a href="/wiki/The_Telephone_Cases" title="The Telephone Cases">The Telephone Cases</a></i></li> <li><a href="/wiki/History_of_television" title="History of television">Television</a> <ul><li><a href="/wiki/Digital_television" title="Digital television">digital</a></li> <li><a href="/wiki/Streaming_television" title="Streaming television">streaming</a></li></ul></li> <li><a href="/wiki/Submarine_communications_cable#Early_history:_telegraph_and_coaxial_cables" title="Submarine communications cable">Undersea telegraph line</a></li> <li><a href="/wiki/History_of_videotelephony" title="History of videotelephony">Videotelephony</a></li> <li><a href="/wiki/Whistled_language" title="Whistled language">Whistled language</a></li> <li><a href="/wiki/Wireless_revolution" class="mw-redirect" title="Wireless revolution">Wireless revolution</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Pioneers</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Nasir_Ahmed_(engineer)" title="Nasir Ahmed (engineer)">Nasir Ahmed</a></li> <li><a href="/wiki/Edwin_Howard_Armstrong" title="Edwin Howard Armstrong">Edwin Howard Armstrong</a></li> <li><a href="/wiki/Mohamed_M._Atalla" title="Mohamed M. Atalla">Mohamed M. Atalla</a></li> <li><a href="/wiki/John_Logie_Baird" title="John Logie Baird">John Logie Baird</a></li> <li><a href="/wiki/Paul_Baran" title="Paul Baran">Paul Baran</a></li> <li><a href="/wiki/John_Bardeen" title="John Bardeen">John Bardeen</a></li> <li><a href="/wiki/Alexander_Graham_Bell" title="Alexander Graham Bell">Alexander Graham Bell</a></li> <li><a href="/wiki/Emile_Berliner" title="Emile Berliner">Emile Berliner</a></li> <li><a href="/wiki/Tim_Berners-Lee" title="Tim Berners-Lee">Tim Berners-Lee</a></li> <li><a href="/wiki/Francis_Blake_(inventor)" title="Francis Blake (inventor)">Francis Blake</a></li> <li><a href="/wiki/Jagadish_Chandra_Bose" title="Jagadish Chandra Bose">Jagadish Chandra Bose</a></li> <li><a href="/wiki/Charles_Bourseul" title="Charles Bourseul">Charles Bourseul</a></li> <li><a href="/wiki/Walter_Houser_Brattain" title="Walter Houser Brattain">Walter Houser Brattain</a></li> <li><a href="/wiki/Vint_Cerf" title="Vint Cerf">Vint Cerf</a></li> <li><a href="/wiki/Claude_Chappe" title="Claude Chappe">Claude Chappe</a></li> <li><a href="/wiki/Yogen_Dalal" class="mw-redirect" title="Yogen Dalal">Yogen Dalal</a></li> <li><a href="/wiki/Daniel_Davis_Jr." title="Daniel Davis Jr.">Daniel Davis Jr.</a></li> <li><a href="/wiki/Donald_Davies" title="Donald Davies">Donald Davies</a></li> <li><a href="/wiki/Amos_Dolbear" title="Amos Dolbear">Amos Dolbear</a></li> <li><a href="/wiki/Thomas_Edison" title="Thomas Edison">Thomas Edison</a></li> <li><a href="/wiki/Lee_de_Forest" title="Lee de Forest">Lee de Forest</a></li> <li><a href="/wiki/Philo_Farnsworth" title="Philo Farnsworth">Philo Farnsworth</a></li> <li><a href="/wiki/Reginald_Fessenden" title="Reginald Fessenden">Reginald Fessenden</a></li> <li><a href="/wiki/Elisha_Gray" title="Elisha Gray">Elisha Gray</a></li> <li><a href="/wiki/Oliver_Heaviside" title="Oliver Heaviside">Oliver Heaviside</a></li> <li><a href="/wiki/Robert_Hooke" title="Robert Hooke">Robert Hooke</a></li> <li><a href="/wiki/Erna_Schneider_Hoover" title="Erna Schneider Hoover">Erna Schneider Hoover</a></li> <li><a href="/wiki/Harold_Hopkins_(physicist)" title="Harold Hopkins (physicist)">Harold Hopkins</a></li> <li><a href="/wiki/Gardiner_Greene_Hubbard" title="Gardiner Greene Hubbard">Gardiner Greene Hubbard</a></li> <li><a href="/wiki/List_of_Internet_pioneers" title="List of Internet pioneers">Internet pioneers</a></li> <li><a href="/wiki/Bob_Kahn" class="mw-redirect" title="Bob Kahn">Bob Kahn</a></li> <li><a href="/wiki/Dawon_Kahng" title="Dawon Kahng">Dawon Kahng</a></li> <li><a href="/wiki/Charles_K._Kao" title="Charles K. Kao">Charles K. Kao</a></li> <li><a href="/wiki/Narinder_Singh_Kapany" title="Narinder Singh Kapany">Narinder Singh Kapany</a></li> <li><a href="/wiki/Hedy_Lamarr" title="Hedy Lamarr">Hedy Lamarr</a></li> <li><a href="/wiki/Roberto_Landell_de_Moura" title="Roberto Landell de Moura">Roberto Landell de Moura</a></li> <li><a href="/wiki/Innocenzo_Manzetti" title="Innocenzo Manzetti">Innocenzo Manzetti</a></li> <li><a href="/wiki/Guglielmo_Marconi" title="Guglielmo Marconi">Guglielmo Marconi</a></li> <li><a href="/wiki/Robert_Metcalfe" title="Robert Metcalfe">Robert Metcalfe</a></li> <li><a href="/wiki/Antonio_Meucci" title="Antonio Meucci">Antonio Meucci</a></li> <li><a href="/wiki/Samuel_Morse" title="Samuel Morse">Samuel Morse</a></li> <li><a href="/wiki/Jun-ichi_Nishizawa" title="Jun-ichi Nishizawa">Jun-ichi Nishizawa</a></li> <li><a href="/wiki/Charles_Grafton_Page" title="Charles Grafton Page">Charles Grafton Page</a></li> <li><a href="/wiki/Radia_Perlman" title="Radia Perlman">Radia Perlman</a></li> <li><a href="/wiki/Alexander_Stepanovich_Popov" class="mw-redirect" title="Alexander Stepanovich Popov">Alexander Stepanovich Popov</a></li> <li><a href="/wiki/Tivadar_Pusk%C3%A1s" title="Tivadar Puskás">Tivadar Puskás</a></li> <li><a href="/wiki/Johann_Philipp_Reis" title="Johann Philipp Reis">Johann Philipp Reis</a></li> <li><a href="/wiki/Claude_Shannon" title="Claude Shannon">Claude Shannon</a></li> <li><a href="/wiki/Almon_Brown_Strowger" title="Almon Brown Strowger">Almon Brown Strowger</a></li> <li><a href="/wiki/Henry_Sutton_(inventor)" title="Henry Sutton (inventor)">Henry Sutton</a></li> <li><a href="/wiki/Charles_Sumner_Tainter" title="Charles Sumner Tainter">Charles Sumner Tainter</a></li> <li><a href="/wiki/Nikola_Tesla" title="Nikola Tesla">Nikola Tesla</a></li> <li><a href="/wiki/Camille_Tissot" title="Camille Tissot">Camille Tissot</a></li> <li><a href="/wiki/Alfred_Vail" title="Alfred Vail">Alfred Vail</a></li> <li><a href="/wiki/Thomas_A._Watson" title="Thomas A. Watson">Thomas A. Watson</a></li> <li><a href="/wiki/Charles_Wheatstone" title="Charles Wheatstone">Charles Wheatstone</a></li> <li><a href="/wiki/Vladimir_K._Zworykin" title="Vladimir K. Zworykin">Vladimir K. Zworykin</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Transmission_medium" title="Transmission medium">Transmission<br />media</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Coaxial_cable" title="Coaxial cable">Coaxial cable</a></li> <li><a href="/wiki/Fiber-optic_communication" title="Fiber-optic communication">Fiber-optic communication</a> <ul><li><a href="/wiki/Optical_fiber" title="Optical fiber">optical fiber</a></li></ul></li> <li><a href="/wiki/Free-space_optical_communication" title="Free-space optical communication">Free-space optical communication</a></li> <li><a href="/wiki/Molecular_communication" title="Molecular communication">Molecular communication</a></li> <li><a href="/wiki/Radio_wave" title="Radio wave">Radio waves</a> <ul><li><a href="/wiki/Wireless" title="Wireless">wireless</a></li></ul></li> <li><a href="/wiki/Transmission_line" title="Transmission line">Transmission line</a> <ul><li><a href="/wiki/Telecommunication_circuit" title="Telecommunication circuit">telecommunication circuit</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Network_topology" title="Network topology">Network topology</a><br />and switching</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Bandwidth_(computing)" title="Bandwidth (computing)">Bandwidth</a></li> <li><a href="/wiki/Telecommunications_link" title="Telecommunications link">Links</a></li> <li><a href="/wiki/Node_(networking)" title="Node (networking)">Nodes</a> <ul><li><a href="/wiki/Terminal_(telecommunication)" title="Terminal (telecommunication)">terminal</a></li></ul></li> <li><a href="/wiki/Network_switch" title="Network switch">Network switching</a> <ul><li><a href="/wiki/Circuit_switching" title="Circuit switching">circuit</a></li> <li><a href="/wiki/Packet_switching" title="Packet switching">packet</a></li></ul></li> <li><a href="/wiki/Telephone_exchange" title="Telephone exchange">Telephone exchange</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Multiplexing" title="Multiplexing">Multiplexing</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Space-division_multiple_access" title="Space-division multiple access">Space-division</a></li> <li><a href="/wiki/Frequency-division_multiplexing" title="Frequency-division multiplexing">Frequency-division</a></li> <li><a href="/wiki/Time-division_multiplexing" title="Time-division multiplexing">Time-division</a></li> <li><a href="/wiki/Polarization-division_multiplexing" title="Polarization-division multiplexing">Polarization-division</a></li> <li><a href="/wiki/Orbital_angular_momentum_multiplexing" title="Orbital angular momentum multiplexing">Orbital angular-momentum</a></li> <li><a href="/wiki/Code-division_multiple_access" title="Code-division multiple access">Code-division</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Concepts</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Communication_protocol" title="Communication protocol">Communication protocol</a></li> <li><a href="/wiki/Computer_network" title="Computer network">Computer network</a></li> <li><a href="/wiki/Data_communication" title="Data communication">Data transmission</a></li> <li><a href="/wiki/Store_and_forward" title="Store and forward">Store and forward</a></li> <li><a href="/wiki/Telecommunications_equipment" title="Telecommunications equipment">Telecommunications equipment</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Telecommunications_network" title="Telecommunications network">Types of network</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cellular_network" title="Cellular network">Cellular network</a></li> <li><a href="/wiki/Ethernet" title="Ethernet">Ethernet</a></li> <li><a href="/wiki/Integrated_Services_Digital_Network" class="mw-redirect" title="Integrated Services Digital Network">ISDN</a></li> <li><a href="/wiki/Local_area_network" title="Local area network">LAN</a></li> <li><a href="/wiki/Mobile_telephony" title="Mobile telephony">Mobile</a></li> <li><a href="/wiki/Next-generation_network" title="Next-generation network">NGN</a></li> <li><a href="/wiki/Public_switched_telephone_network" title="Public switched telephone network">Public Switched Telephone</a></li> <li><a href="/wiki/Radio_network" title="Radio network">Radio</a></li> <li><a href="/wiki/Television_broadcasting" class="mw-redirect" title="Television broadcasting">Television</a></li> <li><a href="/wiki/Telex" title="Telex">Telex</a></li> <li><a href="/wiki/UUCP" title="UUCP">UUCP</a></li> <li><a href="/wiki/Wide_area_network" title="Wide area network">WAN</a></li> <li><a href="/wiki/Wireless_network" title="Wireless network">Wireless network</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Telecommunications_network" title="Telecommunications network">Notable networks</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ARPANET" title="ARPANET">ARPANET</a></li> <li><a href="/wiki/BITNET" title="BITNET">BITNET</a></li> <li><a href="/wiki/CYCLADES" title="CYCLADES">CYCLADES</a></li> <li><a href="/wiki/FidoNet" title="FidoNet">FidoNet</a></li> <li><a href="/wiki/Internet" title="Internet">Internet</a></li> <li><a href="/wiki/Internet2" title="Internet2">Internet2</a></li> <li><a href="/wiki/JANET" title="JANET">JANET</a></li> <li><a href="/wiki/NPL_network" title="NPL network">NPL network</a></li> <li><a href="/wiki/Toasternet" title="Toasternet">Toasternet</a></li> <li><a href="/wiki/Usenet" title="Usenet">Usenet</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Locations</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Category:Telecommunications_in_Africa" title="Category:Telecommunications in Africa">Africa</a></li> <li>Americas <ul><li><a href="/wiki/Category:Telecommunications_in_North_America" title="Category:Telecommunications in North America">North</a></li> <li><a href="/wiki/Category:Telecommunications_in_South_America" title="Category:Telecommunications in South America">South</a></li></ul></li> <li><a href="/wiki/Category:Communications_in_Antarctica" title="Category:Communications in Antarctica">Antarctica</a></li> <li><a href="/wiki/Category:Telecommunications_in_Asia" title="Category:Telecommunications in Asia">Asia</a></li> <li><a href="/wiki/Category:Telecommunications_in_Europe" title="Category:Telecommunications in Europe">Europe</a></li> <li><a href="/wiki/Category:Telecommunications_in_Oceania" title="Category:Telecommunications in Oceania">Oceania</a></li> <li>(<a href="/wiki/List_of_telecommunications_regulatory_bodies" title="List of telecommunications regulatory bodies">Global telecommunications regulation bodies</a>)</li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><span class="nowrap"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4e/Telecom-icon.svg/16px-Telecom-icon.svg.png" decoding="async" width="16" height="16" class="mw-file-element" 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