HFC接入网视频点播业务的网络设计

HFC Access Network Design for Video on Demand service

研究视频点播系统优化设计问题,广电行业中多采用IPQAM来提供视频点播业务,IPQAM射频频率(RF)需求主导了业务的部署和维护费用。视频点播业务网络设计的关键是在保证一定服务性能指标的前提下,估算部署所需最少的IPQAM RF数目。为此提出了一种混合光纤同轴电缆(HFC)接入网视频点播业务的网络设计方法,采用M/M/c/c/n排队模型分析业务高峰期流量,可计算服务组最优IPQAM RF数目,指导视频点播业务的经济部署。数值仿真表明,改进方法能节省费用,在用户规模较小时优势更加明显。

Cable operators mainly use Internet Protocol Quadrature Amplitude Modulation （IPQAM） to provide video on demand service, expenditure of IPQAM radio frequency （RF） dominates the costs of launching and mainte- nance the service. The key of network design for video on demand service is to estimate the least number of IPQAM RF numbers in the guarantee service performance at the time of deployment. This paper provided a new hybrid fiber - coaxial（HFC） access network design formula for video on demand service. The formula used M/M/c/c/n queuing model to analyze the traffic of video on demand system in peak period, and then calculated the optimal IPQAM RF numbers per service group that minimizes the costs of launching new service. Numerical simulations show that this method can save the cost of launching, and the advantage is more obvious in the smaller scale of users.