本文综合评述了城市接入网现有的几种形式 ,着重介绍了 L AN直接接入法。作者认为 ,现有的各种电信接入网和广播电视分配网都可以被考虑改造用作宽带 IP接入网。但这些方法的带宽能力有限 ,只能是一段时期内使用的过渡性方法。从发展来看 ,最近快速兴起的光缆到大楼局域网接入方案是最有发展前途的。 This article reviews several existing forms of access networks in cities and highlights the L AN direct access method. The author believes that all kinds of existing telecommunication access networks and radio and television distribution networks can be considered for transformation as broadband IP access networks. However, the bandwidth capacity of these methods is limited and can only be a transitional method used over a period of time. From the development point of view, the recent rapid rise of cable to the building LAN access program is the most promising.