NTT采用全光无源光网络（PON）为用户提供视频应用、Internet接入和其它宽带宽业务。NTT著名的7t－PON新型接入系统，采用无源双星结构，由无源分光器接收来自中心线路终端的光信号，分束后传送到用户附近的光网络单元或用户家中。这样，采用PON为用户提供FTTC和FTTH业务可以充 NTT uses PON to provide users with video applications, Internet access and other broadband services. NTT’s famous 7t-PON access system uses a passive binary structure. The passive optical splitter receives optical signals from the center line terminal and is split and transmitted to the optical network unit or user’s home near the user. In this way, the use of PON FTTC and FTTH users to provide business can charge