EPON的优点主要表现在

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<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的优点主要表现在：</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><br/></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">　　</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">(1)</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">相对成本低，维护简单，容易扩展，易于升级。</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">结构在传输途中不需电源，没有电子部件，因此容易铺设，基本不用维护，长期运营成本和管理成本的节省很大；</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">系统对局端资源占用很少，模块化程度高，系统初期投入低，扩展容易，投资回报率高；</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">系统是面向未来的技术，大多数</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">系统都是一个多业务平台，对于向全</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">IP</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">网络过渡是一个很好的选择。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><br/></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">　　</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">(2)</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">提供非常高的带宽。</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">目前可以提供上下行对称的</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">1.25Gb/s</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的带宽，并且随着以太技术的发展可以升级到</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">10Gb/s</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><br/></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">　　</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">(3)</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">服务范围大。</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">作为一种点到多点网络，以一种扇出的结构来节省</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">CO</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的资源，服务大量用户。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><br/></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">　　</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">(4)</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">带宽分配灵活，服务有保证。对带宽的分配和保证都有一套完整的体系。</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">可以通过</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">DiffServ</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">、</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">Q/WFQ</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">、</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">WRED</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">等来实现对每个用户进行带宽分配，并保证每个用户的</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">QoS</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">
                                <br/></font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">　　</span><span style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">
                        </font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">但是作为一种新技术，如何进入市场和被市场所认可，取决于很多方面。</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">产品在严格意义上还没有标准。其次是诸如测距、同步等一些技术难点的解决方案的成熟和突发性光器件成本的进一步降低。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><br/></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">本文之前所论述的几种接入方案均提供了某种形式的宽带，但是每个都有其局限性。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">DSL</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">技术由于其距离上的限制，也限制了大量用户的使用。而</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">Cable</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的运营者在建设宽带</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">Cable</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的必要基础设施上比较缓慢，而且这种网络拓扑在提供可靠的</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">QoS</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">上也存在一些问题。而</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">系统可以提供</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">DSL</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">、</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">LAN</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">、</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">Cable Modem</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">等接入方式无法提供的高质量的宽带。这非常适合于</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">FTTB</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">模式，接入到中小型甚至大型商业用户。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><br/></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">在当前的情况下，</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">技术大多会以一种与其他技术相结合的姿态进入市场。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">FTTB/FTTC+DSL</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">，</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">FTTB/FTTC+LAN</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">都是不错的选择。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">DSL</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">和</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">LAN</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">是目前中国宽带的两种主要接入方式。但</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">DSL</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的距离限制挡住了大量的客户，传统的</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">LAN</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">技术也难以灵活地提供和保证用户的带宽。采用</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">技术，不仅可以通过无源传输网络直接连接到服务区域，再进行</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">DSL</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">或</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">LAN</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">扩展，从而为大范围用户提供服务，而且可以集中进行管理和带宽分配。当把</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">ONU</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">集成到</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">DSLAM</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">，使用</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EP0N</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">能使</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">DSL</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">突破传统的</span><chmetcnv wst="on" unitname="m" sourcevalue="1500" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">1500m</font></span></chmetcnv><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的距离，从而增加约</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">50</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">％的用户，</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">DSL</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">可以到达的范围和其潜在的用户群都会增加。通过集成</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">ONU</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">到</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">CMTS</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">（</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">Cable Modem Termination System</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">），</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">可以用来给现有的</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">Cable</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">连接提供带宽，而且可以实现真正的交互式服务，同时降低建设和运营成本。</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">技术还可以用来给固定的无线发射塔提供带宽，很好地解决无线接入技术中如何将上行数据汇集到</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">CO</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">的问题。</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt;"><br/></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">　　从运营商和服务提供商的角度来看，</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">系统可以带来多方面的好处，包括降低安装、管理和运营成本，提高投资回报率，增加新的赢利机会，长期保持竞争优势等。在适当的场合，适时地采用</span><span lang="EN-US" style="BACKGROUND: yellow; mso-bidi-font-size: 10.5pt;"><font face="Times New Roman">EPON</font></span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman';">系统，无论对于原有的运营商还是新兴的运营商，都将是一个明智的选择。</span></p>