本文详细研究了有线电视网中在分前端(如乡镇机房)插入本地节目和数据业务的组网技术Overlay,在性能、成本和下行有效带宽三方面与1310nm多级光电转换网络进行了比较。宜兴市乡镇网络改造应用表明,Overlay叠加技术及其组网方式能有效解决县(市)一乡(镇)网络中大规模、长距离广播信号的传输与本地节目插入和窄播数据业务传送之间的问题,既能完全满足业务的需求,又能节省成本并灵活地加以接入。 This paper studies in detail the Overlay technology of inserting local programs and data services in sub-front-end (such as township computer labs) in CATV network and compares it with 1310nm multi-level photoelectric conversion network in terms of performance, cost and downlink effective bandwidth. The transformation and application of township network in Yixing shows that Overlay superposition technology and its networking mode can effectively solve the transmission of large-scale and long-distance broadcasting signals and the transmission of local program insertion and narrowcast data services in a county (city) and a township (town) network Between the problems, both to fully meet the needs of business, but also save costs and flexibility to be accessed.