CINXE.COM

Tech Stuff - Wireless Alphabet Soup

<!DOCTYPE html> <html lang="en-us"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <link rel="icon" href="http://www.zytrax.com/favicon.ico"> <title>Tech Stuff - Wireless Alphabet Soup</title> <!-- this page originated from http://www.zytrax.com/tech/wireless/soup.html --> <!-- HTTP_USER_AGENT=Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506; .NET CLR 3.5.21022; .NET CLR 1.0.3705; .NET CLR 1.1.4322) --> <style type="text/css"> <!-- /* ZYTRAX STYLE SHEET */ /* google maps */ /* v\:* {behavior:url(#default#VML);} */ /* tag modifiers */ a {text-decoration:none;color:gray;} a:hover {text-decoration:underline;} a:hover.p-f-s {color:black} a:hover.a-n {text-decoration:none;} body {background-color:white;color:black;margin:0px;padding:0px;font:normal 1.0em Verdana,Arial, Helvetica, sans-serif;} code {border:1px solid lightgray;background:mintcream;color:black;font-family:"Courier New", monospace;padding:0 2px} div.l-f table{width:100%;padding:4px;} h1 {font-size:1.5em;;border-width:0 0 5px 0;border-style:solid;border-color:LightGray;padding:4px;color:black} h2 {border-width:0 0 5px 0;border-color:LightGray;border-style:solid;font-size:1.3em;font-weight:bold;padding:4px;color:black} h3 {border-width:0 0 3px 0;border-color:LightGray;border-style:solid;font-size:1.1em;padding:4px;color:black;} h4 {border-width:0 0 2px 0;border-color:LightGray;border-style:solid;font-size:1.0em;padding:2px;color:black;} h5 {border-width:0 0 2px 0;border-color:LightGray;border-style:solid;font-size:1.0em;font-weight:bold;color:black;padding:4px;} h6 {border-width:0 0 1px 0;border-color:LightGray;border-style:solid; font-size:80%;color:black;padding:4px;} pre {white-space:pre-wrap;} img {border:0;} img.center {display:block;margin-left:auto;margin-right:auto;} img.right {display:block;float:right;} img.left {display:block;float:left;} form {border:1px solid #ccc;} input {border:1px solid #999;background:#9bf;} textarea {border:1px solid #999;background:#9bf;} table {margin: 0 auto;} table.t-m-n > tbody > tr > td {border:1px solid #ccc;padding:4px;} table.t-m-s > tbody > tr > td {border:1px solid #ccc;padding:4px;} table.p-m-n > tbody > tr > td {padding:4px;border-collapse:collapse;} table.p-m-s > tbody > tr > td {padding:4px;border-collapse:collapse;} tr {vertical-align:top;} /* end tag modifiers - Printer friendly */ .adv {margin-right:auto;margin-left:auto;width:728px;} .l-b {position:absolute;top:0px;left:0px;font-size:80%;border:0;background:white;color:gray;height:100px;z-index:9;width:100%;} div.l-r #layout {visibility:visible;} div.l-l-fp #layout {visibility:visible;} .l-l {position:absolute;top:100px;left:6px;width:110px;font:10pt Verdana,Helvetica, Arial, sans-serif;z-index:1;} .l-c {margin:105px 170px 0px 125px;padding:4px 20px;border-width:0 1px; border-style:solid; border-color:LightGray; z-index:5; line-height:1.3em;} .l-r {position:absolute;top:100px;right:0;width:160px;background:white;z-index:2;font-size:80%;} /* end printer friendly - begin divs generic (cross browser) */ .i-2 {background: url(../../images/info.gif) no-repeat top left;border-width: 3px 0 3px 0; border-style:solid;border-color:#bbb;font-size:10pt;padding:10px 10px 10px 60px;margin:10px;} .i-3 {background: url(../../../images/info.gif) no-repeat top left;border-width: 3px 0 3px 0; border-style:solid;border-color:#bbb;font-size:10pt;padding:10px 10px 10px 60px;margin:10px;} .l-c-i {padding:10px;} .l-l-fp {position:absolute;top:95px;left:6px;width:120px;z-index:10;text-align:right;font-size:80%;} .l-r-fp {position:absolute;top:95px;right:6px;width:150px;z-index:2;font-size:80%;} .l-f-m {} .l-f {margin:0 200px 0 125px;} .l-p {margin:10px;padding:4px;font:10pt Verdana,Helvetica, Arial, sans-serif;} .l-100 {width:100%;margin:0;} .w-2 {background: url(../../images/warning.gif) no-repeat top left;border-width: 3px 0 3px 0; border-style:solid;border-color:#bbb;font-size:10pt;padding:10px 10px 10px 60px;margin:10px;} .w-3 {background: url(../../../images/warning.gif) no-repeat top left;border-width: 3px 0 3px 0; border-style:solid;border-color:#bbb;font-size:10pt;padding:10px 10px 10px 60px;margin:10px;} /* end divs - begin nav pop-outs */ .n-l-c {color:black;} .n-l1 {padding:0;margin:0;list-style:none;width:100px;} .n-l1p {padding:0;margin:0;list-style:none;text-align:right;color:#339;} .n-l1p-e {font-size:9pt;margin:0;text-align:right;line-height:1.2em;position:relative;color:#339;} .n-l1-e {text-align:right;margin:0;padding:2px;position:relative;} .n-t1-e,.n-t2-e,.n-t3-e,.n-m-l1 {text-align:left;margin:0;padding:2px 5px;border:1px solid black;border-width:1px 1px 0 1px;position:relative;} .n-t1-es,.n-t2-es,.n-t3-es {text-align:left;margin:0;padding:2px 5px;border:1px solid black;border-width:1px 1px 0 1px;position:relative;background:#eee;} .n-t1-v {position:absolute;display:none;padding:0;margin:0;list-style:none;top:100%;right:0;width:100px; border-bottom:1px solid black;background:white;} .n-t1-vr,.n-m-u1 {position:absolute;display:none;padding:0;margin:0;list-style:none; top:100%;right:0;width:100px;border-bottom:1px solid black;background:white;} .n-t2,.n-t3 {position:absolute;display:none;padding:0;margin:0;list-style:none;top:0;right:100%;width:120px;border-bottom:1px solid black;background:white;} /* end pop-up styles - begin nav effects */ .g-c-n:hover {background:#eee;} .g-c-s:hover {background:#eee;} /* W3c pop-ups - selectors ignored by MSIE 6- */ div.n-m:hover > ul {display:block;} div.n-t0:hover > ul {display:block;} li.n-t1-e:hover > ul {display:block;} li.n-t1-es:hover > ul {display:block;} li.n-t1-e:hover, li.n-t1-es:hover,li.n-t2-e:hover,li.n-t2-es:hover,li.n-t3-e:hover,li.n-m-l1:hover {background:#ccc;} li.n-t2-e:hover > ul {display:block;} li.n-t2-es:hover > ul {display:block;} .n-l1-e:hover > ul {display:block;} .n-l1p-e:hover > ul {display:block;} .n-l1-es:hover > ul {display:block;} .n-l2-e:hover > ul {display:block;} .n-l2-es:hover > ul {display:block;} .n-l3-e:hover > ul {display:block;} .n-l3-es:hover > ul {display:block;} li.n-l1-e:hover,li.n-l1p-e:hover,li.n-l2-e:hover,li.n-l2-es:hover, li.n-l3-e:hover, li.n-l3-es:hover,li.n-l4-e:hover {background:#ccc;} /* end pop-up effects - begin generic (cross browser) alpha */ .arrows {font-size:250%;} .a-n {text-decoration:none;} .at {font-family:Verdana,sans-serif;font-size:9pt;margin:0px;text-indent:8px;} .b-1 {font-family:Verdana, sans-serif;} .button {background:#ddd;border:3px outset black;} .b-lg {background-color:#eee;} .b-r {border-width:0 0 0 1px;border-color:#336;border-style:solid;width:150px;} .b-l {border-width:0 1px 0 0;border-color:#336;border-style:solid;width:110px;} .b-b-s {border:1px solid black;} /* color styles */ .c-r, .red {color:red;} .c-b, .blue {color:blue;} .c-lg {color:LightGray;} .c-g {color:gray;} /* end color styles */ .d {font-family:Verdana,sans-serif;font-size:9pt;margin:0px;} .dd {position:absolute;left:0;top:0; font-family:Tahoma,sans-serif;font-size:9pt; visibility:hidden;background:lime;color:black;margin:0px;border:black solid 1px;padding:2px;} .f-d {font-weight:bold;} .f-b-n {border:0;} /* most browsers use an unacceptably small monospace default font */ .g-c-n,.g-b-n {font:110% "Courier New",monospace;border-style:solid;border-color:#ccc;border-width: 1px 1px 1px 5px;background-color:#9bf;padding:5px; color:black;} .g-c-s,.g-b-s,.codegray {font: 80% "Courier New",monospace;border-style:solid;border-color:#ccc;border-width: 1px 1px 1px 5px; background-color:#9bf;padding:5px; color:black;width:inherit;} .g-h-n, .g-s-b {background:#9bf;color:#339;padding:4px;font-size:100%;font-weight:normal;border:1px solid #ccc;} .g-h-nn {background:#9bf;color:#339;padding:4px; font-size:100%;font-weight:normal;} .g-h-ng,.section {background:#339;color:white;font:bold Verdana,sans-serif;padding:4px; text-decoration:none;} .g-h-s {background:#9bf;color:#339;padding:4px; font-size:80%;font-weight:normal;border:1px solid #ccc;} .g-h-ss {background:#9bf;color:#339;padding:4px; font-size:80%;font-weight:normal;} .g-n {text-decoration:none;color:white;} .g-i1-n {margin:5px 5px 5px 20px;} .g-i2-n {margin:5px 5px 5px 30px;} .g-i3-n {margin:5px 5px 5px 40px;} .g-l-n {list-style:none;} .g-sb-n {color:blue;font-size:8pt;line-height:150%;margin:2px;} .g-s-n {background-color:#eee;color:black;font-size:10pt; text-decoration:none;} .h-b {background:#ddd;color:black;font-weight:bold;} .h-150 {line-height:1.5em;} .i-h {margin:5px 5px 10px 60px;padding:5px;} .i-n {border-width: 3px 0 3px 0; border-style:solid;border-color:#bbb;font-size:10pt;padding:10px 10px 10px 60px;margin:10px;} .i-s {border-width: 3px 0 3px 0; border-style:solid;border-color:#bbb;font-size:8pt;margin:10px 10px 10px 60px;padding:10px;} .i-u {width:27px;} .n-l {position:fixed;left:6px;width:110px;} .n-l-fp {left:6px;width:110px;} .n-l-f {font-size:1.0em;margin:2px;text-align:right;line-height:1.2em;color:black;} .n-l-f a {color:black;} .m-h5 {margin:0.5em 0;} .m-h20 {margin:2.0em 0;} .n-b-l {font:1pt Verdana, Arial, Helvetica, sans-serif;border-width:0 0 1px 0;border-style:solid;border-color:#CCF;margin:0px;padding:0px;} .n-l-s {font-size:80%;visibility:hidden;} .n-m {font-size:130%;margin:0;padding:0;float:right;position:relative;} .n-t0 {float:right;position:relative;} .n-t-t {text-align:right;padding:1px 1px 8px 1px;margin:0;} .o-n {list-style:none;} .p-b {background:#eee;text-indent:3em;} .p-m-n,.norm {font-size: 100%;border-spacing:0;border-collapse:collapse;} .p-m-s { font-size:80%;border:0;border-spacing:0;border-collapse:collapse;} .q-i-2 {background: url(../../images/quotes-open.gif) no-repeat top left;} .q-s {border-width: 0 0 0 6px;border-style:solid;border-color:#acf;font-size:8pt;margin:10px 10px 10px 60px;padding:10px;} .t-b-s {font:8pt "Courier New",monospace;border-style:solid;border-color:#ccc;border-width: 1px;background-color:#acf;padding:5px; color:black;} .t-b-n {font:10pt "Courier New",monospace;border-style:solid;border-color:black;border-width: 1px;background-color:#acf;padding:5px; color:black;} /* link/href styles */ .t-dd:hover {background:#ddd;} .w-db:hover {background:#ddd;} .t-ba {color:#aaa;font-weight:bold;} .t-gb {color:blue;background:#eee;} .t-dr {color:red;text-decoration:none;} .t-dw {color:#666;text-decoration:none;} .t-db,.t-dd {color:blue;text-decoration:none;} .t-da {color:black;} .w-db,.t-dn {text-decoration:none;} /* begin text styles */ .t-b {font-size:120%;} .t-b200 {font-size:200%;} .t-c, .center {text-align:center;} .t-g {background:#eee;} .t-h {} div.t-h:hover > div {display:block;} .t-h-1 {display:none;background:#eee;padding:5px;} .t-i {font-style:italic;} .t-l {text-align:left;} .t-n, .g-e-t, .g-e-d {font-size:100%;font-weight:normal;} .t-o {font-weight:bold;} .t-r {text-align:right;} .t-s {font-size:80%;} .t-ss {font-size:60%;} /* table styles */ .t-t-l {margin:0;} .t-td1-l,.t-td1 {border-style:solid;border-width:5px 0 0 0;border-color:#ddd;padding:3px 3px 8px 5px;} .t-td2-l,.t-td2 {border-style:solid;border-width:5px 0 0 0;border-color:#acf;padding:3px 3px 8px 5px;} .t-m {background:#ccc;color:blue;text-decoration:none;} .t-m-n {font-size: 100%;border: 2px solid #ccc;border-spacing:0;border-collapse:collapse;} .t-m-s {font-size:80%;border: 2px solid #ccc;border-spacing:0;border-collapse:collapse;} .vital {font-family:Tahoma,Arial, sans-serif;font-size:12pt;background-color:#ddd; color:black;border-color:red;} /* visibility */ .v-h {visibility:hidden;} /* width styles */ .w-450 {width:450px;} .w-350 {width:350px;} .w-300 {width:300px;} .w-250 {width:250px;} .w-200 {width:200px;} .w-180 {width:180px;} .w-150 {width:150px;} .w-120 {width:120px;} .w-100 {width:100px;} .w-80 {width:80px;} .w-88 {width:88px;} .w-50 {width:50px;} .w-32 {width:32px;} .w-27 {width:27px;} .w-20 {width:20px;} .w-10 {width:10px;} .w-11pc {width:11%;} .w-6pc {width:6%;} /* Gecko/W3C specific */ abbr[title]:after {content:"";} abbr[title]:hover:after {content:" (" attr(title)")";} /* W3C pop-ups */ .n-l2,.n-l3,.n-l4 {position:absolute;display:none;padding:0;margin:0;list-style:none;top:0;left:100%;width:120px;border-bottom:1px solid black;background:#EEE;font:8pt Verdana,Helvetica, Arial, sans-serif} .n-l2-e,.n-l3-e,.n-l4-e {text-align:left;margin:0;padding:2px 5px;border:1px solid black;border-width:1px 1px 0 1px;position:relative;} .n-l2-es,.n-l3-es,.n-l4-es {text-align:left;margin:0;padding:2px 5px;border:1px solid black;border-width:1px 1px 0 1px;position:relative;background:white;} /* end - start expand divs */ .v-f {display:none;} .v-o {display:block;} /* end expand divs */ #toplogo {float:left;vertical-align:bottom;} .g-ci-s {font:8pt "Courier New",monospace;border-style:solid;border-color:#ccc;border-width: 1px 1px 1px 5px; background-color:#acf;color:black;} .jp-h-n {position:absolute;left:50%;top:50%;text-indent:4px;font-family:Verdana,sans-serif;font-size:10pt; visibility:hidden;background:#EEEEEE;color:blue;text-decoration:none;} .n-l-u {font-family:Verdana,sans-serif;top:60px;left:6px;width:110px;background:white;} .n-l-l {font-size: 9pt;color:black;text-align:right;line-height:150%;} .n-p-f {color:#336;font:9pt/16pt Verdana,sans-serif;text-decoration:none;text-indent:6px;} .n-p-n {background:#EEE;color:#336;font:9pt Verdana,sans-serif;text-indent:6px;} .n-p-n a {text-indent:6px;display:block;} .n-p-o {font:10pt Verdana,sans-serif; background:#DDD;color:blue;text-decoration:none;height:16pt;} .n-t-n {color:#336;font:10pt Verdana,sans-serif;text-decoration:none;margin:0;padding:0;} .n-t-s {color:white;font: 8pt Verdana,sans-serif;text-decoration:none;padding:0 3px 0 0} .n-t-sr {color:#336;font: 8pt Verdana,sans-serif;text-decoration:none;padding:0 3px 0 0} .p-b-h {visibility:hidden;} .p-n-h {position:absolute;left:0;top:0;text-indent:4px;font-family:Verdana,sans-serif;font-size:small; visibility:hidden;background:#EEE;color:blue;text-decoration:none;border:1px blue solid;width:110px;} .p-f-s {font-family: Verdana, sans-serif; font-size:8pt; color:silver; background:white;text-decoration:none;} --> </style> <style type="text/css" media="print"> <!-- /* ZYTRAX STYLE SHEET PRINT TEMPLATE */ .l-l {display:none;} .l-r {display:none;} .l-c {width:600px;margin:0;padding:30px 10px 5px 10px; border-width:0;} .l-f {margin:5px;} .n-t-t {display:none;} .n-t0 {display:none;} .adv {display:none;} --> </style> <script type="text/javascript"> <!-- // copyright ZYTRAX, Inc. 1994 - 2014 // you may use this javascript code at your own risk. // we would like you to keep the copyright statement intact but don't insist on it. // If you make improvements mail us a copy or make it available on your own web site. // global variables var topall = new Array(2); var lownav = new Array(2); var lowpop = new Array(2); var rightnav = new Array(2); var rightpop = new Array(2); var x = 0; // global menu level var way = 'h'; var menu = null; var menus = null; var pop1 = new Array(2); var fs = 1.0; var days = new Array(7); var months = new Array(12); days = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"]; months = ["January","February","March","April","May","June","July","August","September","October","November","December"]; function showtime() { var thistime = ""; var nowtime ="" var nowam = "AM"; var now = new Date(); var nowhour = now.getHours(); if (nowhour > 12) { nowam = "PM"; nowhour = nowhour - 12; } else if (nowhour == 0){ nowhour = 12; } var nowminutes = now.getMinutes(); if (nowminutes < 10 ){ nowminutes = "0" + nowminutes; } nowtime = nowhour + ":" + nowminutes + " " + nowam; thistime = days[now.getDay()] + " " + now.getDate() + " " + months[now.getMonth()] + " " + now.getFullYear() + ", " + nowtime; return thistime; } // -- W3C DOM specific code - first choice always function lock(num){ // lock relies on a style which end with -l rollover = document.getElementById("l" + num); if(rollover){ cn = rollover.className if((pos = cn.lastIndexOf("-")) != -1){ bcn = cn.substring(0,pos + 1); scn = cn.substring(pos +1); if(scn == "f" || scn == "o"){ rollover.className = bcn + "l"; } } } } function fontchange(fix) { x = document.getElementsByTagName("div"); for(i = 0; i < x.length; i++) { if(x[i].className == "l-c"){ if(x[i].style.fontSize == ""){ fs = 1.0; x[i].style.fontSize = "1.0em"; } if(fix == "d"){ if(fs <= 0.8){ break; }else{ fs = parseFloat(fs - 0.1); x[i].style.fontSize = fs + "em"; } }else{ if(fs >= 1.5){ break; }else{ fs = parseFloat(fs + 0.1); x[i].style.fontSize = fs + "em"; } } break; } } } function toggle(tid){ var dis; var disa; if(document.getElementById){ dis = document.getElementById(tid); disa = document.getElementById(tid + 'a'); }else{ dis = document.all.tid; disa = document.all.tid + 'a'; } if(dis.style.display == 'block'){ dis.style.display = 'none'; disa.style.display = 'block'; }else{ dis.style.display = 'block'; disa.style.display = 'none'; } } function gotourl($url) { window.location = $url; } function mailus(mbox,stub,subject) { mail = "mailto:"+mbox+"@"+stub; if(subject != ""){ mail = mail+"?SUBJECT="+"A-Z: "+subject; } window.location = mail; return; } // W3C compliant uses CSS popups not JS //--> </script> <script type="text/javascript"> <!-- // copyright ZYTRAX, Inc. 1994 - 2014 // you may use this javascript code at your own risk. // we would like you to keep the copyright statement intact but don't insist on it. // If you make improvements mail us a copy or make it available on your own web site. // global variables var topall = new Array(2); var lownav = new Array(2); var lowpop = new Array(2); var rightnav = new Array(2); var rightpop = new Array(2); var x = 0; // global menu level var way = 'h'; var menu = null; var menus = null; var pop1 = new Array(2); var fs = 1.0; var days = new Array(7); var months = new Array(12); days = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"]; months = ["January","February","March","April","May","June","July","August","September","October","November","December"]; function showtime() { var thistime = ""; var nowtime ="" var nowam = "AM"; var now = new Date(); var nowhour = now.getHours(); if (nowhour > 12) { nowam = "PM"; nowhour = nowhour - 12; } else if (nowhour == 0){ nowhour = 12; } var nowminutes = now.getMinutes(); if (nowminutes < 10 ){ nowminutes = "0" + nowminutes; } nowtime = nowhour + ":" + nowminutes + " " + nowam; thistime = days[now.getDay()] + " " + now.getDate() + " " + months[now.getMonth()] + " " + now.getFullYear() + ", " + nowtime; return thistime; } // -- W3C DOM specific code - first choice always function lock(num){ // lock relies on a style which end with -l rollover = document.getElementById("l" + num); if(rollover){ cn = rollover.className if((pos = cn.lastIndexOf("-")) != -1){ bcn = cn.substring(0,pos + 1); scn = cn.substring(pos +1); if(scn == "f" || scn == "o"){ rollover.className = bcn + "l"; } } } } function fontchange(fix) { x = document.getElementsByTagName("div"); for(i = 0; i < x.length; i++) { if(x[i].className == "l-c"){ if(x[i].style.fontSize == ""){ fs = 1.0; x[i].style.fontSize = "1.0em"; } if(fix == "d"){ if(fs <= 0.8){ break; }else{ fs = parseFloat(fs - 0.1); x[i].style.fontSize = fs + "em"; } }else{ if(fs >= 1.5){ break; }else{ fs = parseFloat(fs + 0.1); x[i].style.fontSize = fs + "em"; } } break; } } } function toggle(tid){ var dis; var disa; if(document.getElementById){ dis = document.getElementById(tid); disa = document.getElementById(tid + 'a'); }else{ dis = document.all.tid; disa = document.all.tid + 'a'; } if(dis.style.display == 'block'){ dis.style.display = 'none'; disa.style.display = 'block'; }else{ dis.style.display = 'block'; disa.style.display = 'none'; } } function gotourl($url) { window.location = $url; } function mailus(mbox,stub,subject) { mail = "mailto:"+mbox+"@"+stub; if(subject != ""){ mail = mail+"?SUBJECT="+"A-Z: "+subject; } window.location = mail; return; } // W3C compliant uses CSS popups not JS //--> </script> </head> <body> <!-- Page Header plus top nav bar --> <div class="l-b"> <!--if expr="!${isMob}" --> <a href="http://www.zytrax.com"><img id="toplogo" src="http://www.zytrax.com/images/zytrax-logo-info.png" alt="ZYTRAX Info Logo"></a> <!-- desktop browsers --> <p class="n-t-t"><a href="http://www.zytrax.com/feedback.htm" class="n-t-sr">mail us</a> &nbsp;&#124;&nbsp; <a href="http://www.zytrax.com/run/mailpage.php" class="n-t-sr">mail this page</a></p> <div class="n-t0"> <a href="http://www.zytrax.com/Company/contacts.html" class="n-t-sr">contact us</a> </div> <div class="n-t0"> <a href="http://www.zytrax.com/training/" class="n-t-sr">training</a> &nbsp;&#124;&nbsp; </div> <div class="n-t0"> <a href="http://www.zytrax.com/tech/" class="n-t-sr">tech stuff</a> &nbsp;&#124;&nbsp; <ul class="n-t1-v"> <li class="n-t1-es"><a href="http://www.zytrax.com/tech/" class="t-da">tech stuff</a> <!-- tertiary pop-outs --> <ul class="n-t2"> <li class="n-t2-e"><a title="collection of technology stuff" href="http://www.zytrax.com/tech/" class="t-da">tech stuff</a></li> <li class="n-t2-es t-da">web stuff <ul class="n-t3"> <li class="n-t3-e"><a title="collection of web based technology stuff" href="http://www.zytrax.com/tech/web/" class="t-da">web stuff</a></li> <li class="n-t3-e"><a title="collection of UA strings for most browsers" href="http://www.zytrax.com/tech/web/browser_ids.htm" class="t-da">browser ids</a></li> <li class="n-t3-e"><a title="collection of mobile UA strings" href="http://www.zytrax.com/tech/web/mobile_ids.html" class="t-da">mobile ids</a></li> <li class="n-t3-e"><a title="our HTML5 page conversion process and thoughts" href="http://www.zytrax.com/tech/css/html5.html" class="t-da">HTML5 Convert</a></li> <li class="n-t3-e"><a title="how we do server-side browser sniffing with apache" href="http://www.zytrax.com/tech/web/browser_sniffing.html" class="t-da">browser sniffing</a></li> <li class="n-t3-e"><a title="apache environmental variables" href="http://www.zytrax.com/tech/web/env_var.htm" class="t-da">apache env's</a></li> <li class="n-t3-e"><a title="apache server side includes - extensive notes and examples" href="http://www.zytrax.com/tech/web/ssi.htm" class="t-da">apache ssi</a></li> <li class="n-t3-e"><a title="our css pop-up/pop-down/flyout menus for Gecko/Opera/MSIE" href="http://www.zytrax.com/tech/css/workarounds.html#popout" class="t-da">pop-outs (css)</a></li> <li class="n-t3-e"><a title="most of those annoying HTML entity codes that we forget all the time" href="http://www.zytrax.com/tech/web/entities.html" class="t-da">html entities</a></li> </ul> </li> <li class="n-t2-es t-da">open guides <ul class="n-t3"> <li class="n-t3-e"><a href="http://www.zytrax.com/books/" class="t-da">open guides</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/books/dns" class="t-da">dns guide</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/books/ldap" class="t-da">ldap guide</a></li> </ul> </li> <li class="n-t2-e"><a title="Decimal to Hexidecimal to Binary conversion - even Octal!" href="http://www.zytrax.com/tech/protocols/hex.html" class="t-da">Dec>Hex>Bin</a></li> <li class="n-t2-es t-da">survival stuff <ul class="n-t3"> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/" title="a series of survival guides for some popular open source software" class="t-da">survival stuff</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/ssl.html" class="t-da">ssl/tls &amp; x.509</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/asn1.html" class="t-da">ASN.1</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/kerberos.html" class="t-da">kerberos</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/postfix.html" class="t-da">postfix</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/cron.html" class="t-da">cron</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/encryption.html" class="t-da">cryptography</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/survival/wxwidgets.html" class="t-da">wxWidgets</a></li> </ul> </li> <li class="n-t2-es t-da">audio stuff <ul class="n-t3"> <li class="n-t3-e"><a title="Pages about Digital Audio, Primers, Calculator, Equalization, FFT" href="http://www.zytrax.com/tech/audio/" class="t-da">audio stuff</a></li> <li class="n-t3-e"><a title="Fundamentals, harmonics, overtone, partials, loudness, ADSR envelopes" href="http://www.zytrax.com/tech/audio/sound.html" class="t-da">sound primer</a></li> <li class="n-t3-e"><a title="Sound digitization, time domain, frequency domain" href="http://www.zytrax.com/tech/audio/digital-sound.html" class="t-da">digital sound</a></li> <li class="n-t3-e"><a title="common frequencies of instruments and in life" href="http://www.zytrax.com/tech/audio/audio.html" class="t-da">frequencies</a></li> <li class="n-t3-e"><a title="equalization principles, octaves, sound metering and FFT" href="http://www.zytrax.com/tech/audio/equalization.html" class="t-da">equalization</a></li> <li class="n-t3-e"><a title="Acoustic caculators for musical notes and FFT bin frequencies" href="http://www.zytrax.com/tech/audio/calculator.html" class="t-da">calculators</a></li> <li class="n-t3-e"><a title="Yet another audio glossary" href="http://www.zytrax.com/tech/audio/glossary.html" class="t-da">glossary</a></li> </ul> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/web/regex.htm" class="t-da">regex stuff</a></li> <li class="n-t2-es t-da">cable stuff <ul class="n-t3"> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/" class="t-da">cable stuff</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/tech_lan.htm" class="t-da">lan wiring</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/mixed.html" class="t-da">lan &amp; telephone</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/tech_rs232.htm" class="t-da">rs232 stuff</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/heavy.htm" class="t-da">serial primer</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/pc/serial.html" class="t-da">usb 3.2 &amp; firewire</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/pc/monitors.htm" class="t-da">displays</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/layer_1/cables/cables_jacks.htm" class="t-da">modular jacks</a></li> </ul> </li> <li class="n-t2-es t-da">protocol stuff <ul class="n-t3"> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/" class="t-da">protocol stuff</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/tcp.html" class="t-da">tcp-udp-icmp</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/ip-classes.html" class="t-da">ipv4</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/ip-classes.html#calculator" class="t-da">ipv4 Calculator</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/ipv6.html" class="t-da">ipv6</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/ipv6.html#calculator" class="t-da">ipv6 Calculator</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/isdn" class="t-da">isdn-bri</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/protocols/lan" class="t-da">802 lan</a></li> <li class="n-t3-e"><a href="http://www.zytrax.com/tech/ss7" class="t-da">ss7 &amp; sigtran</a></li> </ul> </li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/pc/" class="t-da">pc stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/wireless/" class="t-da">wireless stuff</a></li> <li class="n-t2-es t-da">css stuff <ul class="n-t3"> <li class="n-t3-e"><a title="collection of css notes and experiences including css menus and css liquid layout" href="http://www.zytrax.com/tech/css/" class="t-da">css stuff</a></li> <li class="n-t3-e"><a title="Notes on our experience with converting to css based liquid layouts - including blow by blow css" href="http://www.zytrax.com/tech/css/layoutnotes.html" class="t-da">css liquid design</a></li> <li class="n-t3-e"><a title="we have used css menus since mid-2003 - blow-by-blow implementation notes" href="http://www.zytrax.com/tech/css/workarounds.html#popout" class="t-da">css menus</a></li> <li class="n-t3-e"><a title="some practical solutions on using css" href="http://www.zytrax.com/tech/css/workarounds.html" class="t-da">css notes</a></li> <li class="n-t3-e"><a title="css shortforms at a glance" href="http://www.zytrax.com/tech/css/shortcut.html" class="t-da">css short-forms</a></li> <li class="n-t3-e"><a title="css selectors and quick overview with links to the W3C specs" href="http://www.zytrax.com/tech/css/syntax.html" class="t-da">css overview</a></li> </ul> </li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/codes.htm" class="t-da">ascii codes</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/data_rates.htm" class="t-da">data rate stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/telephony/" class="t-da">telephony stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/mech/" class="t-da">mech. stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/protocols/hex.html" class="t-da">Dec>Hex>Bin</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/lang/" class="t-da">language stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/electronics/" class="t-da">electronic stuff</a></li> <li class="n-t2-e"><a href="http://www.zytrax.com/tech/rfcs/" class="t-da">rfc stuff</a></li> </ul> </li> <li class="n-t1-e"><a href="http://www.zytrax.com/security/" class="t-da">Security</a></li> </ul> </div> <!-- close div l-b --> </div> <!-- begin body table --> <div class="l-c"> <p class="adv"> <script type="text/javascript"><!-- google_ad_client = "ca-pub-9419480011552853"; /* wireless leaderboard */ google_ad_slot = "3639218670"; google_ad_width = 728; google_ad_height = 90; //--> </script> <script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script> </p> <h1>Tech Stuff - Wireless Alphabet Soup</h1> <p>It really can be a nightmare. All that gobbledegook terminology. We define a number of terms to help ease the wireless pain threshold:</p> <p><b>Enlightenment:</b> The 802.11 standards are now freely <a href="http://standards.ieee.org/getieee802" class="t-db">available in PDF format</a> once they are over 6 months old.</p> <table class="p-m-s"> <tr > <td id="16qam" class="w-100 t-td1">16QAM</td> <td class="t-td2">Modulation scheme. 16 - Quadrature amplitude modulation uses <a href="#qam" class="t-db">QAM</a> with 4 amplitudes and 4 phases to allow 16 values to be transmitted.</td> </tr> <tr > <td id="64qam" class="t-td1">64QAM</td> <td class="t-td2">Modulation scheme. 64 - Quadrature amplitude modulation uses <a href="#qam" class="t-db">QAM</a> with 8 amplitudes and 8 phases to allow 64 values to be transmitted.</td> </tr> <tr > <td id="256qam" class="t-td1">256QAM</td> <td class="t-td2">Modulation scheme. 256 - Quadrature amplitude modulation uses <a href="#qam" class="t-db">QAM</a> with 16 amplitudes and 16 phases to allow 256 values to be transmitted. Used in 802.11ac and ad (WiGig).</td> </tr> <tr > <td class="t-td1">802.11</td> <td class="t-td2">IEEE standard that is the base for wireless Lans. Defined the protocol that is used throughout the 11x group of standards. Supported a number of different PHYs (Phyical Layers) including FHSS (Frequency Hopping Spread Spectrum) and DSSS (Direct Sequence Spread Spectrum). Supported both wireless and Infrared (IR) media. Data rates up to 2Mb. ISM band 2.400-2.483.5 GHz. Modulation techniques - BPSK, QPSK.</td> </tr> <tr > <td class="t-td1">802.11a</td> <td class="t-td2">IEEE standard. Uses the protocol defined in 802.11. DSSS (Direct Sequence Spread Spectrum) at data rates up to 54Mb. UNII band 5.15-5.25 GHz, 5.25-5.35 GHz, 5.725-5.825 GHz. Modulation techniques - 16QAM, 64QAM, QPSK, BPSK.</td> </tr> <tr > <td class="t-td1">802.11b</td> <td class="t-td2">IEEE standard. Uses the protocol defined in 802.11. DSSS (Direct Sequence Spread Spectrum) at data rates up to 11Mb. ISM band 2.400-2.483.5 GHz. Modulation techniques - CCK, DBPSK, DQPSK.</td> </tr> <tr > <td class="t-td1">802.11g</td> <td class="t-td2">IEEE standard. Uses the protocol defined in 802.11. DSSS (Direct Sequence Spread Spectrum) at data rates up to 54Mb. ISM band 2.400-2.483.5 GHz. Modulation techniques - OFDM with 16QAM, 64QAM, QPSK, BPSK and falls back 11b's CCK, DBPSK, DQPSK.</td> </tr> <tr > <td class="t-td1">802.11n</td> <td class="t-td2">IEEE standard in progress. Proposes speeds up to 74 Mb with data throughput of u 270Mb. Not (as of 5/2007) ratified, target completion is March 2009.</td> </tr> <tr > <td class="t-td1">802.16</td> <td class="t-td2">IEEE wireless MAN standard (a.k.a. <a href="wimax" class="t-db">WiMAX</a>). Operates in the licensed 10-66 GHz frequency range and provides speeds up 70 Mbps over distances to 31 miles.</td> </tr> <tr > <td id="ber" class="t-td1">BER</td> <td class="t-td2">Bit Error Rate or Ratio (BER) defines the number of error bits received over time and is expressed as a negative power - thus a BER of 10<sup>-5</sup> is one error per 100,000 bits of transmission. Wireline serial transmission typically has a BER in the 10<sup>-10</sup> to 10<sup>-12</sup> range whereas most radio systems are in the 10<sup>-3</sup> to 10<sup>-6</sup> range.</td> </tr> <tr > <td id="bpsk" class="t-td1">BPSK</td> <td class="t-td2">Modulation scheme. Binary Phase Skift Keying uses <a href="#psk" class="t-db">PSK</a> with two phases of 180<sup>o</sup>.</td> </tr> <tr > <td id="cck" class="t-td1">CCK</td> <td class="t-td2">Modulation scheme. Complimentary Code Keying uses a systems of symbols encoded using <a href="#dqpsk" class="t-db">DQPSK</a>. Used in 802.11b to achieve the 5.5 and 11 Mb rates.</td> </tr> <tr > <td id="dpsk" class="t-td1">DPSK</td> <td class="t-td2">Modulation scheme. Generic term. Differential Phase Skift Keying compares the value received in each phase to previous values. Implementations use DBPSK or DQPSK.</td> </tr> <tr > <td id="dbpsk" class="t-td1">DBPSK</td> <td class="t-td2">Modulation scheme. Differential Binary Phase Skift Keying uses <a href="#dpsk" class="t-db">DPSK</a> with two phases of 180<sup>o</sup>.</td> </tr> <tr > <td id="dqpsk" class="t-td1">DQPSK</td> <td class="t-td2">Modulation scheme. Differential Quaternary or Quadriphase Phase Skift Keying uses <a href="#dpsk" class="t-db">DPSK</a> with four phase shifts of 90<sup>o</sup>.</td> </tr> <tr > <td id="mimo" class="t-td1">MIMO</td> <td class="t-td2">Generic term. Multiple-input multiple-output refers to the use of multiple antennas at the transmitter and receiver and makes it paticularly useful for <a href="#ofdm" class="t-db">OFDM</a>. Each sub-channel may be sent on an optimally designed antenna thus increasing the reliability of the complete transmission.</td> </tr> <tr > <td id="ofdm" class="t-td1">OFDM</td> <td class="t-td2">Multiplexing scheme. Generic term. Orthogonal Frequency Division Multiplexing divides a single frequency into multiple sub-frequencies each of which is independent (orthogonal) and may use different modulation techniques (such as <a href="#bpsk" class="t-db">BPSK</a> or <a href="#16qam" class="t-db">16-QAM</a>). Since the characteristics of each sub-channel are different, and hence subject to varying interference patterns, this allows more reliability in reception of the complete transmission.</td> </tr> <tr > <td id="psk" class="t-td1">PSK</td> <td class="t-td2">Modulation scheme. Generic term. Phase Skift Keying in which the absolute value received in each phase is used. Implementations use BPSK or QPSK.</td> </tr> <tr > <td id="qam" class="t-td1">QAM</td> <td class="t-td2">Modulation scheme. Generic term. Quadrature amplitude modulation uses values from two carriers which are out of phase by 90&deg; modulated to create a single output. By using different phases and varying the amplitude combinations are created such as 4 phases (90&deg;) x 4 amplitudes = 16 (16-QAM). Implementations typically use 16-QAM, 64-QAM, 128-QAM and 256-QAM.</td> </tr> <tr > <td id="qpsk" class="t-td1">QPSK</td> <td class="t-td2">Modulation scheme. Quaternary or Quadriphase Phase Skift Keying uses <a href="#psk" class="t-db">PSK</a> with four phase shifts of 90<sup>o</sup>.</td> </tr> <tr> <td id="wifi" class="t-td1">Wi-Fi</td> <td class="t-td2">Term used to define wireless devices that are certifie by the Wi-Fi Alliance and hence will inter-operate with other such devices. Standards used are based on the IEEE 802.11 series.</td> </tr> <tr> <td id="wimax" class="t-td1">WiMAX</td> <td class="t-td2">WiMAX (Worldwide Interoperability for Microwave Access) is an industry coalition formed to advance the <a href="#802-16" class="t-db">802.16</a> standards by certifying inter-operability between products. Similar objective to Wi-Fi.</td> </tr> </table> <hr> <p class="p-m-n"><br>Problems, comments, suggestions, corrections (including broken links) or something to add? Please take the time from a busy life to 'mail us' (at top of screen), the webmaster (below) or <a href="javascript:mailus('info-support','zytrax.com','Support Issue')" class="t-db">info-support at zytrax</a>. You will have a warm inner glow for the rest of the day.</p> <!-- end body div l-c --> </div> <div class="l-l"> <!-- left hand navigation --> <div class="n-l"> <p class="c-g t-b t-o m-h5 t-r">Tech Stuff</p> <!-- first row of navigation CSS format --> <ul class="n-l1p"> <li class="n-l1p-e"> <a href="http://www.zytrax.com/tech" class="n-l-c">tech home</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="Digital Audio - primers, calculators, equalization, frequency tables, file formats, glossary - a mere splash in the ocean" href="http://www.zytrax.com/tech/audio/" class="n-l-c">audio stuff</a> <ul class="n-l2"> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/audio/sound.html" class="n-l-f">sound primer</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/audio/digital-sound.html" class="n-l-f">digital primer</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/audio/audio.html" class="n-l-f">note frequencies</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/audio/equalization.html" class="n-l-f">eq, meters &amp; fft</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/audio/calculator.html" class="n-l-f">calculators</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/audio/formats.html" class="n-l-f">files &amp; codecs</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/audio/glossary.html" class="n-l-f">glossary</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="Browser IDs, SSIs, Apache Configuration, regular expressions" href="http://www.zytrax.com/tech/web/" class="n-l-c">web stuff</a> <ul class="n-l2"> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/web/browser_ids.htm" class="n-l-f">browser ids</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/web/mobile_ids.html" class="n-l-f">mobile_ids</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/web/env_var.htm" class="n-l-f">apache env vars</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/web/ssi.htm" class="n-l-f">apache ssi</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/css/workarounds.html#popout" class="n-l-f">css popout menus</a></li> <li class="n-l2-e"><a title="most of those annoying HTML entity codes that we forget all the time" href="http://www.zytrax.com/tech/web/entities.html" class="n-l-f">html entities</a></li> <li class="n-l2-e"><a title="Decimal to Hexidecimal to Binary conversion - even Octal!" href="http://www.zytrax.com/tech/protocols/hex.html" class="n-l-f">dec > hex > bin</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a href="http://www.zytrax.com/tech/dom/" class="n-l-c">dom stuff</a><br> <ul class="n-l2"> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/dom/guide.html" class="n-l-f">dom guide</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/dom/w3c_dom.html" class="n-l-f">page explorer</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/dom/navigate.html" class="n-l-f">dom navigation</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="CSS is about a lot more than STYLE. Wheezes, table-less layouts, CSS pop-ups, CSS Shortcuts" href="http://www.zytrax.com/tech/css/" class="n-l-c">css stuff</a> <ul class="n-l2"> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/css/layoutnotes.html" class="n-l-f">css liquid design</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/css/workarounds.html#popout" class="n-l-f">css popout menus</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/css/workarounds.html" class="n-l-f">css notes</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/css/syntax.html" class="n-l-f">css syntax</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/css/shortcut.html" class="n-l-f">css short-forms</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="includes PHP, Ruby and some Java stuff (all about obscure solutions to stupid problems)" href="http://www.zytrax.com/tech/lang/" class="n-l-c">language stuff</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="quick overview 'cos we always forget - not that we ever knew much - now includes a nifty browser-based tester" href="http://www.zytrax.com/tech/web/regex.htm" class="n-l-c">regex stuff</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="rfc ordered by subject" href="http://www.zytrax.com/tech/rfcs/" class="n-l-c">rfc stuff</a> <ul class="n-l2"> <li title="dns rfcs" class="n-l2-e"><a href="http://www.zytrax.com/books/dns/apd/" class="n-l-f">dns rfcs</a></li> <li title="ldap rfcs" class="n-l2-e"><a href="http://www.zytrax.com/books/ldap/apc/" class="n-l-f">ldap rfcs</a></li> <li title="ipv6 rfcs" class="n-l2-e"><a href="http://www.zytrax.com/tech/protocols/ipv6.html#rfcs" class="n-l-f">ipv6 rfcs</a></li> <li title="tls/x.509 rfcs" class="n-l2-e"><a href="http://www.zytrax.com/tech/survival/ssl.html#rfcs" class="n-l-f">tls/x.509 rfcs</a></li> <li title="some other subjects - we only update these when we are active - some lists are consequently long in the tooth" class="n-l2-e"><a href="http://www.zytrax.com/tech/rfcs" class="n-l-f">other rfcs</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="TCP/IP, IPv4, IPv6, ISDN, LAN, VoIP, ITU Multi-Media" href="http://www.zytrax.com/tech/protocols/" class="n-l-c">protocol stuff</a> <ul class="n-l2"> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/protocols/tcp.html" class="n-l-f">tcp, udp, icmp</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/protocols/ip-classes.html" class="n-l-f">ipv4</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/protocols/ipv6.html" class="n-l-f">ipv6</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/protocols/isdn/" class="n-l-f">isdn</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/survival/ssl.html" class="n-l-f">ssl/tls/x.509</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/ss7/" class="n-l-f">ss7 &amp;sigtran</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/protocols/lan/" class="n-l-f">802.3 lan</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="PC Parallel Ports, LAN wiring, RS232, Centronics, DIN" href="http://www.zytrax.com/tech/layer_1/" class="n-l-c">cable stuff</a> <ul class="n-l2"> <li title="10baseT, 100base-TX/T4, 1000baseT, 10Gbase-T, RJ45, STP" class="n-l2-e"><a href="http://www.zytrax.com/tech/layer_1/cables/tech_lan.htm" class="n-l-f">lan pinouts</a></li> <li title="mixing telephony and 802.3 LAN can be done on cat5/5e/6 wiring" class="n-l2-e"><a href="http://www.zytrax.com/tech/layer_1/mixed.html" class="n-l-f">lan &amp; telephone</a></li> <li title="RS 232 pinouts on db9, db24 and T1" class="n-l2-e"><a href="http://www.zytrax.com/tech/layer_1/cables/tech_rs232.htm" class="n-l-f">rs232 pinouts</a></li> <li class="n-l2-e"><a href="http://www.zytrax.com/tech/layer_1/cables/heavy.htm" class="n-l-f">serial primer</a></li> <li title="USB 2.0, 3.0, 3.1 and 3.2 plus Firewire (i.Link) IEE 1394" class="n-l2-e"><a href="http://www.zytrax.com/tech/pc/serial.html" class="n-l-f">usb &amp; firewire</a></li> <li title="some information about display and monitors/console interfaces inclusing VGA, HDMI, DVI and Thunderbolt" class="n-l2-e"><a href="http://www.zytrax.com/tech/pc/monitors.htm" class="n-l-f">displays</a></li> <li title="modular jack is the term we should use for those telephone and lan connectors" class="n-l2-e"><a href="http://www.zytrax.com/tech/layer_1/cables/cables_jacks.htm" class="n-l-f">modular jacks</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="10baseT, 100base-TX/T4, 1000baseT, 10Gbase-T, RJ45, STP" href="http://www.zytrax.com/tech/layer_1/cables/tech_lan.htm" class="n-l-c">lan wiring</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="DB9, DB25 pinouts, RJ45 serial, T1 and RS standards alphabet soup" href="http://www.zytrax.com/tech/layer_1/cables/tech_rs232.htm" class="n-l-c">rs232 wiring</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="Decimal to Hex and Binary conversion table - even a description of Octal!" href="http://www.zytrax.com/tech/protocols/hex.html" class="n-l-c">dec > hex > bin</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="character sets ain't as simple as they look" href="http://www.zytrax.com/tech/codes.htm" class="n-l-c">character sets</a> <ul class="n-l2"> <li title="pretty much all the characters sets in the known universe including utf-7, 8 and 16" class="n-l2-e"><a href="http://www.zytrax.com/tech/characters/" class="n-l-f">character sets</a></li> <li title="ascii variant of international reference alphabet 5 (ira5)" class="n-l2-e"><a href="http://www.zytrax.com/tech/codes.htm" class="n-l-f">ascii codes</a></li> <li title="international reference alphabet 5 (ascii's cousin)" class="n-l2-e"><a href="http://www.zytrax.com/tech/ia5.html" class="n-l-f">ia5 codes</a></li> <li title="all that &trade; &amp; &copy; stuff" class="n-l2-e"><a href="http://www.zytrax.com/tech/web/entities.html" class="n-l-f">html entities</a></li> <li title="silly page containing a bunch of fonts in various sizes including your PCs defaults" class="n-l2-e"><a href="http://www.zytrax.com/tech/web/fonts.html" class="n-l-f">web fonts</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="The T series, E series and J series and then all that optical stuff (OC-12 etc.)" href="http://www.zytrax.com/tech/data_rates.htm" class="n-l-c">data rate stuff</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="Even us electronic guys gotta know how to screw it together, if you get our drift" href="http://www.zytrax.com/tech/mech/" class="n-l-c">mechanical stuff</a> <ul class="n-l2"> <li title="fastener (screw) head styles - surprising number of choices" class="n-l2-e"><a href="http://www.zytrax.com/tech/mech/heads.htm" class="n-l-f">head styles</a></li> <li title="threads for imperial (UNF, UNC) &amp; metric sizes" class="n-l2-e"><a href="http://www.zytrax.com/tech/mech/threads.htm" class="n-l-f">threads</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="A collection of howtos including Samba3 as PDC, FreeBSD firewalls" href="http://www.zytrax.com/tech/howtos/" class="n-l-c">howto stuff</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="A collection of survival guides - quick overviews - to popular software" href="http://www.zytrax.com/tech/survival/" class="n-l-c">survival stuff</a> <ul class="n-l2"> <li title="tls and x.509 (ssl) certificates - warning: headache inducing stuff" class="n-l2-e"><a href="http://www.zytrax.com/tech/survival/ssl.html" class="n-l-f">ssl/tls/x.509</a></li> <li title="Abstract Syntax Notation. 1 (ASN.!) and Distinguished Encoding Rules (DER) - not for the faint hearted. Pass the pain medication, we feel a headache coming on." class="n-l2-e"><a href="http://www.zytrax.com/tech/survival/asn1.html" class="n-l-f">ASN.1 &amp; DER</a></li> <li title="Kerberos is great - but tough, oh my, tough stuff" class="n-l2-e"><a href="http://www.zytrax.com/tech/survival/kerberos.html" class="n-l-f">kerberos</a></li> <li title="We've used postfix for years but always forget which of the 27 million parameters to use" class="n-l2-e"><a href="http://www.zytrax.com/tech/survival/postfix.html" class="n-l-f">postfix</a></li> <li title="Symetric, asymetric, MACs, hashes - eye watering stuff" class="n-l2-e"><a href="http://www.zytrax.com/tech/survival/encryption.html" class="n-l-f">encryption</a></li> <li title="Just what time is it in Kuala Lumpur, and what's that got to do with cron?" class="n-l2-e"><a href="http://www.zytrax.com/tech/survival/cron.html" class="t-db">cron</a></li> <li title="Gotta love wxWidgets - free, fantastic, flexible - but hard to see the wood for the trees sometimes" class="n-l2-e"><a href="http://www.zytrax.com/tech/survival/wxwidgets.html" class="n-l-f">wxWidgets</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="Our wireless overview, Calculators, Fresnel zones, links to 'heavy' stuff, some early 802.11 stuff (mostly wi-fi related)" href="http://www.zytrax.com/tech/wireless/" class="n-l-c">wireless stuff</a> <ul class="n-l2"> <li title="our irreverent general intro to wirelss - purist will not like this page" class="n-l2-e"><a href="http://www.zytrax.com/tech/wireless/intro.htm" class="n-l-f">overview</a></li> <li title="wireless calculators for system budgets, free-space loss, fresnel effects and a bunch of other stuff" class="n-l2-e"><a href="http://www.zytrax.com/tech/wireless/calc.htm" class="n-l-f">calculators</a></li> <li title="fresnel effect explanation - well, we can understand it" class="n-l2-e"><a href="http://www.zytrax.com/tech/wireless/fresnel.htm" class="n-l-f">fresnel effects</a></li> <li title="our outrageously biased description of frequency hopping versus direct sequence for spread spectrum" class="n-l2-e"><a href="http://www.zytrax.com/tech/wireless/fh_ds.htm" class="n-l-f">fh vs ds</a></li> <li title="some terminology covering 802 standards and modulation techniques" class="n-l2-e"><a href="http://www.zytrax.com/tech/wireless/soup.html" class="n-l-f">wireless soup</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="Pinouts - USB, DIN, Firewire, VGA, DVI, HDMI, DisplayPort and Thunderbolt, I/O interface speeds, Screen sizes including HD" href="http://www.zytrax.com/tech/pc/" class="n-l-c">pc stuff</a> <ul class="n-l2"> <li title="din and mini-din for older PCs" class="n-l2-e"><a href="http://www.zytrax.com/tech/pc/din.htm" class="n-l-f">din &amp; mini-din</a></li> <li title="802.3 LAN stuff" class="n-l2-e"><a href="http://www.zytrax.com/tech/layer_1/cables/tech_lan.htm" class="n-l-f">802.3 lan</a></li> <li title="connection of monitors has changed over the years from clunky VGA to svelte HDMI - all the pinouts you could hope for" class="n-l2-e"><a href="http://www.zytrax.com/tech/pc/monitors.htm" class="n-l-f">monitor pinouts</a></li> <li title="serial (db9, db24) connections - slow but trusty" class="n-l2-e"><a href="http://www.zytrax.com/tech/layer_1/cables/tech_rs232.htm" class="n-l-f">serial stuff</a></li> <li title="usb pinouts and descriptions of power levels for usb 1, 2 and 3 - also includes firewire" class="n-l2-e"><a href="http://www.zytrax.com/tech/pc/serial.html" class="n-l-f">usb &amp; firewire</a></li> <li title="pc interfaces are changing and getting faster - we can never keep up - list of interfaces and their speeds" class="n-l2-e"><a href="http://www.zytrax.com/tech/pc/interfaces.html" class="n-l-f">pc interfaces</a></li> <li title="we get confused about most things - just what is 1080p - pc and tv screen resolution table with some explanations" class="n-l2-e"><a href="http://www.zytrax.com/tech/pc/resolution.html" class="n-l-f">screen resolutions</a></li> </ul> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="Electronic glossary, some old experiments with 3.3/5V protection and early BGA designs" href="http://www.zytrax.com/tech/electronics/" class="n-l-c">electronic stuff</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="ragbag collection of links that we publish from time to time - maybe useful, maybe not" href="http://www.zytrax.com/links" class="n-l-c">tech links</a> </li> </ul> <ul class="n-l1p"> <li class="n-l1p-e"> <a title="Our DNS and LDAP for Rocket Scientists guides" href="http://www.zytrax.com/books" class="n-l-c">open guides</a> <ul class="n-l2"> <li title="dns for rocket scientists" class="n-l2-e"><a href="http://www.zytrax.com/books/dns/" class="n-l-f">dns guide</a></li> <li title="ldap for rocket scientists" class="n-l2-e"><a href="http://www.zytrax.com/books/ldap/" class="n-l-f">ldap guide</a></li> </ul> </li> </ul> <p class="t-r"> <a title="RSS (2.0) Feed - right click on icon, select 'Copy Link URL' or 'Copy Shortcut', paste into RSS Feed Reader, or drag and drop into RSS Feed Reader" href="http://www.zytrax.com/zytrax.rss" class="n-l-c"><img class="w-32 center" src="http://www.zytrax.com/images/rss.png" alt="RSS Feed Icon"></a> </p> <p class="p-b-h t-r">If you are happy it's OK - but your browser is giving a less than optimal experience on our site. You could, at no charge, upgrade to a W3C standards compliant browser such as <a href="http://www.mozilla.org" class="t-db">Firefox</a></p> </div> </div> <div class="l-r"> <!-- right menu --> <div class="w-150"> <!-- SiteSearch Google --> <p class="c-g t-b t-o m-h8">Search</p> <form class="f-b-n" method="get" action="http://www.google.com/custom" target="_top"> <table> <tr> <td style="white-space: nowrap"> <input type="hidden" name="domains" value="www.zytrax.com"> <input class="b-lg" type="text" name="q" size="16" maxlength="255" value=""> </td></tr> <tr> <td style="white-space: nowrap"> <table> <tr> <td> <input type="radio" name="sitesearch" value="" checked="checked"><span class="t-s">web</span> </td> <td> <input type="radio" name="sitesearch" value="www.zytrax.com" ><span class="t-s">zytrax.com</span> </td> </tr> </table> <input class="b-lg" type="submit" name="sa" value="Google Search"> <input type="hidden" name="client" value="pub-9419480011552853"> <input type="hidden" name="forid" value="1"> <input type="hidden" name="ie" value="ISO-8859-1"> <input type="hidden" name="oe" value="ISO-8859-1"> <input type="hidden" name="safe" value="active"> <input type="hidden" name="cof" value="GALT:#008000;GL:1;DIV:#336699;VLC:663399;AH:center;BGC:FFFFFF;LBGC:336699;ALC:0000FF;LC:0000FF;T:000000;GFNT:0000FF;GIMP:0000FF;LH:50;LW:355;L:http://www.zytrax.com/images/zytrax-info-google.gif;S:http://www.zytrax.com/tech;FORID:1;"> <input type="hidden" name="hl" value="en"> </td></tr></table> </form> <!-- SiteSearch Google --> <!-- share page feature --> <div class="t-h"><p><span class="t-g">Share</span></p> <div class="t-h-1"> Icons made by <a href="https://www.flaticon.com/authors/icomoon" title="Icomoon">Icomoon</a> from <a href="https://www.flaticon.com/" title="Flaticon">www.flaticon.com</a> is licensed by <a href="http://creativecommons.org/licenses/by/3.0/" title="Creative Commons BY 3.0" target="_blank">CC 3.0 BY</a></div></div> <a href="http://www.facebook.com/share.php?u=http://www.zytrax.com/tech/wireless/soup.html&amp;h=Tech%20Stuff%20-%20Wireless%20Alphabet%20Soup"><img class="w-32" title="add page to facebook" src="http://www.zytrax.com/images/facebook.png" alt="share page via facebook"></a> <a href="http://twitter.com/home/?status=Useful%20page%20http://www.zytrax.com/tech/wireless/soup.html"><img class="w-32" title="tweet this page" src="http://www.zytrax.com/images/twitter.png" alt="tweet this page"></a> <p class="c-g t-b t-o m-h5">Page<p> <a class="a-n" href="http://www.zytrax.com/feedback.htm"><img class="w-32" title="Page comment feature" src="http://www.zytrax.com/images/mail.png" alt="email us"></a> <a class="a-n" href="http://www.zytrax.com/run/mailpage.php"><img class="w-32" title="Send to a friend" src="http://www.zytrax.com/images/mailfriend.png" alt="Send to a friend feature"></a> <a class="a-n" href="#" onclick="window.print();return false;"><img class="w-32" title="print page" src="http://www.zytrax.com/images/printpage.png" alt="print this page"></a> <a class="a-n" title="View page full width - suppresses left and right hand menus" href="http://www.zytrax.com/tech/wireless/soup.html?pf=yes"><img class="w-32" src="http://www.zytrax.com/images/fullwidth.png" alt="Display full width page"></a> <a class="a-n" href="#" onclick="fontchange('d');return false;"><img class="w-32" title="Decrease font size" src="http://www.zytrax.com/images/smaller.png" alt="Decrease font size"></a> <a class="a-n" href="#" onclick="fontchange('i');return false;"><img class="w-32" title="Increase font size" src="http://www.zytrax.com/images/bigger.png" alt="Increase font size"></a> <p class="c-g t-b t-o m-h5">Wireless</p> <p class="c-g t-b t-o m-h5">Theory Stuff</p> <p> <a href="http://et.nmsu.edu/~etti/fall96/communications/db/db.html" target="_blank" class="w-db">the decibel</a><br> </p> <p class="c-g t-b t-o m-h5">Interesting Stuff</p> <p> <a href="http://sss-mag.com" target="_blank" class="w-db">ss magazine</a><br> <a href="http://wireless.wikia.com/wiki/Wi-Fi" target="_blank" class="w-db">wifi wiki</a><br> </p> <p class="c-g t-b t-o m-h5">Bibliographies</p> <p> <a href="http://w3.antd.nist.gov/wctg/manet/wirelesspropagation_bibliog.html" target="_blank" class="w-db">radio propagation (NIST)</a><br> </p> <p class="c-g t-b t-o m-h5">Standards</p> <p> <a href="http://standards.ieee.org/getieee802" target="_blank" class="w-db">IEEE 802 Stds</a><br> </p> <p class="c-g t-b t-o m-h5">Frequencies</p> <p> <a href="http://www.ntia.doc.gov/osmhome/allochrt.html" target="_blank" class="w-db">US Frequencies (NTIA)</a><br> <a href="http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/h_sf01678.html" target="_blank" class="w-db">Canada (CRTC)</a><br> <a href="http://www.ofcom.org.uk/static/archive/ra/topics/spectrum-strat/uk-fat/uk-fat2002.htm" target="_blank" class="w-db">UK (ofcom)</a><br> </p> <p class="c-g t-b t-o m-h5">Our Pages</p> <p> <a href="http://www.zytrax.com/tech/wireless" >wireless home</a><br> <a href="http://www.zytrax.com/tech/wireless/intro.htm" >wireless overview</a><br> <a href="http://www.zytrax.com/tech/wireless/calc.htm" >our calculators</a><br> <a href="http://www.zytrax.com/tech/wireless/fresnel.htm" >fresnel effect</a><br> <a href="http://www.zytrax.com/tech/wireless/decibel.htm" >dreaded decibel</a><br> <a href="http://www.zytrax.com/tech/wireless/802_mac.htm" >802.11 MAC</a><br> <a href="http://www.zytrax.com/tech/wireless/802_phy.htm" >802.11 PHY</a><br> <a href="http://www.zytrax.com/tech/wireless/fh_ds.htm" >fh vs ds</a><br> <a href="http://www.zytrax.com/tech/wireless/soup.html" >alphabet soup</a><br> </p> </div> <p class="c-g t-b t-o">Site</p> <a class="a-n" href="http://www.zytrax.com/about_site.htm#css"><img class="w-32" src="http://www.zytrax.com/images/css.png" alt="CSS Technology"></a> <a class="a-n" href="http://www.zytrax.com/security/spf.html"><img title="SPF Record Conformant Domain" class="w-32" src="http://www.zytrax.com/images/spf.png" alt="SPF Record Conformant Domain"></a> </div> <div class="l-f"> <!-- standard footer full width --> <table> <tr> <td class="p-f-s t-l"> Copyright &copy; 1994 - 2024 ZyTrax, Inc.<br> All rights reserved. <a href="http://www.zytrax.com/legal.html" class="p-f-s">Legal</a> and <a href="http://www.zytrax.com/privacy.html" class="p-f-s">Privacy</a> </td> <td class="t-c"><a href="https://www.zytrax.com" target="_blank" class="p-f-s">site by zytrax</a><br> <a href="https://www.javapipe.com" target="_blank" class="p-f-s">hosted by javapipe.com</a></td> <td class="p-f-s t-r"> <a href="javascript:mailus('web-master','zytrax.com','About Web site')" class="p-f-s">web-master at zytrax</a><br> Page modified: January 20 2022. </td> </tr> </table> </div> <!-- pop-out tables only if Javascript supported --> <!-- only css menus --> </body> </html>

Pages: 1 2 3 4 5 6 7 8 9 10