IPTV--三网融合的开端

IPTV与目前的3个运营网（有线电视网、Internet和电信网）及其业务直接相关。但不同运营商对IPTV业务有不同定位。电信运营商认为IPTV业务体现于电视节目在IP网中的组织和传送形式，有线电视网络运营商认为IPTV业务是利用有线电视网来提供数字电视节目和电视节目以外的信息服务。由于IPTV业务分为广播业务和交互型业务两大类，支撑这两类业务的承载网也相应地分别采用单向广播网和双向交互网，因而在承载网层很难融合。融合工作将在业务层发生，即充分利用已经存在的两个承载网来经济、高效地发展业务。IPTV中既拥有广播型业务，又拥有组播型业务，还拥有交互型业务，将是三网融合的开端。

IPTV- Beginning of Triple Play

IPTV is directly related to three operation networks (the cable TV network, Internet and telecom network) and the services they offer. However, different network operators have varying expectations for IPTV services. For telecom operators, IPTV services organize and transport TV programs over IP networks; while for cable TV operators, IPTV services provide digital TV programs and other information services through cable TV networks. IPTV services are broadly categorized into broadcast and interactive services, which are supported by unidirectional broadcast networks and bidirectional interactive networks respectively. Therefore, convergence of the bearer networks is hard to be implemented. Instead, the convergence will occur on the service layer, that is, to make full use of two existing bearer networks to develop services in an economical and efficient way. IPTV is capable of delivering broadcast, multicast as well as interactive services. It is expected to be a beginning of triple play.