communication subnet meaning in English

通信子网

The normal user must go through the access network and backbone to access the internet via icp there are always high - rate and broadband lines connected to the backbone , the backbone of telecom can provide wide enough bandwidth for all the data transmission as more and more optic fiber with wdm and dwdm technologies have been paved . but " the last mile " from user ' s home to central office is still narrow - band and analog , which becomes bottom - neck of the communication subnet preventing it from being widen
一般用户使用internet时要经过接入网，电信主干网，最后达到icp ( internetcontentprovider ：因特网内容提供商) 。其中icp一般有着高速宽带的线路与主干网相连，而主干网由于波分复用或密集波分复用的光纤技术的大量使用，使得其可提供足够的带宽使用，但是，接入网? ?从用户家庭到电信网的局端的这“最后一公里” ，仍然是窄带的、模拟的，这“最后一公里”就是电信网宽带化的瓶颈。