[推荐]WiZone®技术与无线宽带城域网
<h1 align="center" style="MARGIN: 17pt 0cm 16.5pt; TEXT-ALIGN: center;"><i style="mso-bidi-font-style: normal;"><span lang="EN-US" style="FONT-FAMILY: "Bookman Old Style";">W<span style="COLOR: red;">i</span>Zone</span></i><span lang="EN-US" style="FONT-FAMILY: 宋体;">®</span><span style="FONT-FAMILY: 宋体;">技术与无线宽带城域网<span lang="EN-US"><p></p></span></span></h1><p class="MsoNormal" style="MARGIN: 7.8pt 0cm; TEXT-INDENT: 21pt; mso-para-margin-top: .5gd; mso-para-margin-right: 0cm; mso-para-margin-bottom: .5gd; mso-para-margin-left: 0cm; mso-char-indent-count: 2.0;"><i style="mso-bidi-font-style: normal;"><span lang="EN-US"><font face="Times New Roman">WiFi</font></span></i><i style="mso-bidi-font-style: normal;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">终端产品的丰富推动了</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span></i><i style="mso-bidi-font-style: normal;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">网络的发展，把本来为室内覆盖设计的技术和标准（</span><span lang="EN-US"><font face="Times New Roman">WLAN</font></span></i><i style="mso-bidi-font-style: normal;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">）勉强推向室外。</span><span lang="EN-US"><font face="Times New Roman">AP</font></span></i><i style="mso-bidi-font-style: normal;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">有限的覆盖范围用于无线城域网时，势必造成不可想象的基站密度（</span><span lang="EN-US"><font face="Times New Roman">100</font></span></i><i style="mso-bidi-font-style: normal;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">多个</span><span lang="EN-US"><font face="Times New Roman">/Km</font></span></i><i style="mso-bidi-font-style: normal;"><sup><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">2</font></span></sup></i><i style="mso-bidi-font-style: normal;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">），带来巨大的网络造价、工程难度和维护成本。扩大</span><span lang="EN-US"><font face="Times New Roman">AP</font></span></i><i style="mso-bidi-font-style: normal;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的覆盖范围，降低基站密度成为实现无线城域网的关键技术，</span></i><i style="mso-bidi-font-style: normal;"><span lang="EN-US" style="FONT-FAMILY: "Bookman Old Style"; mso-bidi-font-size: 10.5pt;">W<span style="COLOR: red;">i</span>Zone</span></i><i style="mso-bidi-font-style: normal;"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">®</span></i><i style="mso-bidi-font-style: normal;"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">技术把标准<span lang="EN-US">WiFi AP</span>的覆盖范围从视距（<span lang="EN-US">LoS</span>）的<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="100" unitname="m"><span lang="EN-US">100m</span></chmetcnv>扩大到<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="1700" unitname="m"><span lang="EN-US">1700m</span></chmetcnv>，从非视距（<span lang="EN-US">NLoS</span>）的<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="60" unitname="m"><span lang="EN-US">60m</span></chmetcnv>扩大到<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="300" unitname="m"><span lang="EN-US">300m</span></chmetcnv>，把实现无线城域网时的基站密度降低到<span lang="EN-US">1/10</span>。</span><span lang="EN-US"><p></p></span></i></p><p class="MsoNormal" style="MARGIN: 7.8pt 0cm; TEXT-INDENT: 21pt; mso-para-margin-top: .5gd; mso-para-margin-right: 0cm; mso-para-margin-bottom: .5gd; mso-para-margin-left: 0cm; mso-char-indent-count: 2.0;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">自从</span><span lang="EN-US"><font face="Times New Roman">1997</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">年</span><span lang="EN-US"><font face="Times New Roman">802.11</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">标准（世界范围开放频率，</span><chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="2.4" unitname="g"><span lang="EN-US"><font face="Times New Roman">2.4G</font></span></chmetcnv><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">和</span><chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="5.8" unitname="g"><span lang="EN-US"><font face="Times New Roman">5.8G</font></span></chmetcnv><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">）问世以来，在</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">联盟的推动下，</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">产品市场得到了快速发展，尤其是近几年，多样化的</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">终端（如：</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">笔记本</span><span lang="EN-US"><font face="Times New Roman">/</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">掌上电脑、</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">游戏机、</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">手机、</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">照相机</span><span lang="EN-US"><font face="Times New Roman">/</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">摄像机等）丰富多彩。</span><span lang="EN-US"><font face="Times New Roman">ABI Research</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">研究报告表明：截止</span><span lang="EN-US"><font face="Times New Roman">2006</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">底</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">芯片总出货量</span><span lang="EN-US"><font face="Times New Roman">5</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">亿片，</span><span lang="EN-US"><font face="Times New Roman"> 2006</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">年一年出货</span><span lang="EN-US"><font face="Times New Roman">2</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">亿片，预计</span><span lang="EN-US"><font face="Times New Roman">2012</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">年年出货量将达</span><span lang="EN-US"><font face="Times New Roman">10</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">亿片。另一个研究机构</span><span lang="EN-US"><font face="Times New Roman">In-Stat</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">统计：</span><span lang="EN-US"><font face="Times New Roman">2006</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">年</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">笔记本</span><span lang="EN-US"><font face="Times New Roman">8400</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">万台，增长</span><span lang="EN-US"><font face="Times New Roman">33%</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">；</span><span lang="EN-US"><font face="Times New Roman">2007</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">年底将达到</span><span lang="EN-US"><font face="Times New Roman">1.1</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">亿台；</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">游戏机、手机、手持多媒体播放器等消费类市场增长强劲。</span></p><p class="MsoNormal" style="MARGIN: 7.8pt 0cm; TEXT-INDENT: 21pt; mso-para-margin-top: .5gd; mso-para-margin-right: 0cm; mso-para-margin-bottom: .5gd; mso-para-margin-left: 0cm; mso-char-indent-count: 2.0;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">在品种多样、数量巨大的</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">终端市场的推动下，</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">网络也从局部热点（</span><span lang="EN-US"><font face="Times New Roman">Hotspots</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">）向“热区”（</span><span lang="EN-US"><font face="Times New Roman">Hotzone</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">）发展，从室内延展到室外。但是不可回避的是，</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">作为室内局部网络（</span><span lang="EN-US"><font face="Times New Roman">WLAN</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">）技术有着天生的缺陷――覆盖范围小，用其构建无线区域网或无线城域网，基站密度会很大，尤其在人群密集的城市中心，由于建筑物和树木的遮挡，其基站密度就会更大，通过传输模型计算和实际工程经验估算，每平方公里大约需要</span><span lang="EN-US"><font face="Times New Roman">100</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">多个无线接入点（</span><span lang="EN-US"><font face="Times New Roman">AP</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">）。虽然</span><span lang="EN-US"><font face="Times New Roman">AP</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的价格不贵，但上行有线网络、场地、相关设备和运行维护的成本和难度确实很大。</span></p><p class="MsoNormal" style="MARGIN: 7.8pt 0cm; TEXT-INDENT: 21pt; mso-para-margin-top: .5gd; mso-para-margin-right: 0cm; mso-para-margin-bottom: .5gd; mso-para-margin-left: 0cm; mso-char-indent-count: 2.0;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">因此，扩大</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">基站的覆盖范围是建立</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">无线城域网的关键技术突破点。</span></p><p class="MsoNormal" style="MARGIN: 7.8pt 0cm; TEXT-INDENT: 21pt; mso-para-margin-top: .5gd; mso-para-margin-right: 0cm; mso-para-margin-bottom: .5gd; mso-para-margin-left: 0cm; mso-char-indent-count: 2.0;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">有人简单的认为增加</span><span lang="EN-US"><font face="Times New Roman">AP</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的输出功率就可以扩大</span><span lang="EN-US"><font face="Times New Roman">AP</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的覆盖范围。其实不然，因为</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">基站（</span><span lang="EN-US"><font face="Times New Roman">AP</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">）与无线客户端（</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">笔记本电脑、</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">手机等）是双向通讯网络，仅仅增加</span><span lang="EN-US"><font face="Times New Roman">AP</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的发射功率，却不能增加</span><span lang="EN-US"><font face="Times New Roman">WiFi</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">终端的发射功率，上下行的系统总增益不对称，无法实际有效地增加</span><span lang="EN-US"><font face="Times New Roman">AP</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的覆盖范围。</span></p><p class="MsoNormal" style="MARGIN: 7.8pt 0cm; TEXT-INDENT: 21pt; mso-para-margin-top: .5gd; mso-para-margin-right: 0cm; mso-para-margin-bottom: .5gd; mso-para-margin-left: 0cm; mso-char-indent-count: 2.0;"><span lang="EN-US" style="FONT-FAMILY: "Bookman Old Style"; mso-bidi-font-size: 10.5pt;">W<span style="COLOR: red;">i</span>Zone</span><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">®</span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">技术完全兼容<span lang="EN-US">WiFi</span>的标准，并在<span lang="EN-US">802.11</span>国际标准的基础上着重扩展基站的覆盖距离，通过在有限地增加基站发射功率的同时大大提高了基站的接收灵敏度（－<span lang="EN-US">98dBm/11Mbps</span>），</span><span lang="EN-US" style="FONT-FAMILY: "Bookman Old Style"; mso-bidi-font-size: 10.5pt;">W<span style="COLOR: red;">i</span>Zone</span><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">®</span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">基站在与标准<span lang="EN-US">WiFi</span>终端构成的无线传输系统中实现了上下行对称的系统增益，从而有效地扩大了</span><span lang="EN-US" style="FONT-FAMILY: "Bookman Old Style"; mso-bidi-font-size: 10.5pt;">W<span style="COLOR: red;">i</span>Zone</span><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">®</span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">基站的覆盖范围。例如，一个<span lang="EN-US">20dBm</span>的<span lang="EN-US">AP</span>加上<span lang="EN-US">6dBi</span>全向天线的覆盖半径，在非视距条件下不超过<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="60" unitname="m"><span lang="EN-US">60m</span></chmetcnv>，面积约<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue=".01" unitname="km"><span lang="EN-US">0.01Km</span></chmetcnv><sup><span lang="EN-US">2</span></sup>，</span><span lang="EN-US" style="FONT-FAMILY: "Bookman Old Style"; mso-bidi-font-size: 10.5pt;">W<span style="COLOR: red;">i</span>Zone</span><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">®</span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">基站的非视距覆盖半径可达到<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="300" unitname="m"><span lang="EN-US">300m</span></chmetcnv>以上，面积约<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue=".28" unitname="km"><span lang="EN-US">0.28Km</span></chmetcnv><sup><span lang="EN-US">2</span></sup>，是标准<span lang="EN-US">WiFi AP 28</span>倍。即使在构建无线城域网的实践中保守设计，也可以把基站密度降低到<span lang="EN-US">1/10</span>，即每平方公里十几个基站。<span lang="EN-US"><p></p></span></span></p><p class="MsoNormal" style="MARGIN: 7.8pt 0cm; TEXT-INDENT: 21pt; mso-para-margin-top: .5gd; mso-para-margin-right: 0cm; mso-para-margin-bottom: .5gd; mso-para-margin-left: 0cm; mso-char-indent-count: 2.0;"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt;">基站密度的降低不仅减少了网络造价，而且工程难度、网络维护的成本也相应降低，为构造无线城域网提供一个新的解决方案。</span></p> <p>自己顶一个吧。</p> <p>学习了，谢谢</p>
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