网络协议电视频道快速切换研究

网络协议电视（Internet Protocol Television，IPTV）已经成为新一代网络（Next Generation Net-work，NGN）中最具潜力的应用，主要由于其具有随时随地都能发送电视节目的特性。随着IEEE 802.16d/e的规格制订，它具有高带宽及低延迟的能力，因此适合作为发送多媒体串流的服务。此外，它也提供讯号高涵盖率、行动性支持以及非视线功能。我们可以利用IEEE 802.16d/e提供发送IPTV串流的媒介，并提出一个简单但却有效的IPTV频道切换算法以维持频道切换的时间在一个可容许的范围内。提出的算法根据热门频道及个人化频道的预载，以减少因为网络传输所造成的延迟，达到快速切换频道的目的。最后，通过实验结果证实算法的效能。

Research on Fast Channel Switching of Internet Protocol Television

Internet Protocol Television has become an application with the highest potential in Next Genera-tion Network （NGN）, which is mainly because its characters of sending television program at anytime and any-where. With the formulation of IEEE 802.16d/e, it has ability capacity of high bandwidth and low latency so that it is adapted to the service of multimedia streaming. In addition, it offers a high cover rate signal, operations support and non-line of sight. We can use IEEE 802.16d/e to offer the medium for sending IPTV streaming, and put for-ward a simple and efficiency algorithm of IPTV channel switch to keep the channel zapping time into a reasonable range. According to the preload of hot channel and personal channel, the algorithm can reduce the latency caused by network transmission to realize fast channel switching. Finally, the results show that the algorithm is useful.