Cable TV Network Expansion And Bidirectional Transformation

Cable TV Network is one of the indispensable important components in the modern social life, for example:people can find TV in hotels, public places, cars, planes, ships, trains and many other places. Cable television network plays an important role in spreading information and entertainment. With the improvement of living quality, people put forward higher requirements for the radio and television networks. Then radio and television operators introduce digital TV, Video on demand, Broadband Internet access and other new business to meet the requirements.The research is based on the device increasing and replacement, at the same time through the comparison of the CMTS+CM、EPON+LAN、EPON+EOC、RFoG、Fiber Deep HFC five different kinds of network access technology, to choose one to make certain changes to the original unidirectional cable TV network, to realize the Network Bidirectional Transformation. This paper takes Bidirectional Transformation in a certain area of a city for example, to make concrete analysis of the transformation demand, how to finalize and construct it. At the same time, it also analyze technology features, application, realization of EPON+EOC in detail. Bidirectional transformation backbone to PON technology, by adding new OLT and ONU, transfer the mixture of broadcast and narrowcast signals to OLT through wavelength division multiplexing technology in the front room, and then transferred to the optical node through the OLT, the broadcast signals directly go into the light station, narrowcasting data signals converts into radio frequency via ONU, mix with each other in the light station and then transmitted to the users’ home. After reaching the users’ home, the television signals are directly transmitted into the set-top box for TV watching, the data signal sent to EOC terminal for Internet access.For the network expansion, the whole network is divided into three parts, the front room, transmission networks, distribution networks. The expansion of the front room uses methods of increasing usable area, establishing branch room, and improving modulation efficiency of channel. The expansion of the transmission networks uses methods of adding the number of optical cable while applying WDM technology. The expansion of the distribution networks uses methods of reducing the user number covered by each light node, as well as upgrading the network to 1GHz bandwidth. Finally the network expansion is achieved. This thesis takes Wanlong machine room expansion of Fuzhou broadcast & TV network for instance, to concretely analyze the transformation demand, how to finalize and construct it.The selected bidirectional transformation and network expansion examples in this paper reached their goals:the former achieved a successful transformation into a two-way transmission network, the latter increased 36 downlink optical output ports and added 40 uplink access ports. Both of these two examples are consistent with the design and construction specifications, create good conditions for operators to better serve the users, also lay a good foundation for them to increase revenue.