Sunday 20 March 2011

IPTV via satellite

Although IPTV and conventional satellite TV distribution have been seen as complementary technologies, they are likely to be increasingly used together in hybrid IPTV networks that deliver the highest levels of performance and reliability. IPTV is largely neutral to the transmission medium, and IP traffic is already routinely carried by satellite for Internet backbone trunking and corporate VSAT networks.[46] The use of satellite to carry IP is fundamental to overcoming the greatest shortcoming of IPTV over terrestrial cables – the speed/bandwidth of the connection.

The copper twisted pair cabling that forms the last mile of the telephone/broadband network in many countries is not able to provide a sizeable proportion of the population with an IPTV service that matches even existing terrestrial or satellite digital TV distribution. For a competitive multi-channel TV service, a connection speed of 20Mbit/s is likely to be required, but unavailable to most potential customers.[47] The increasing popularity of high definition TV (with twice the data rate of SD video) increases connection speed requirements, or limits IPTV service quality and connection eligibility even further.

However, satellites are capable of delivering in excess of 100Gbit/s via multi-spot beam technologies, making satellite a clear emerging technology for implementing IPTV networks. Satellite distribution can be included in an IPTV network architecture in several ways. Simplest to implement is an IPTV-DTH architecture, in which hybrid DVB/broadband set-top boxes in subscriber homes integrate satellite and IP reception to give near-infinite bandwidth with return channel capabilities. In such a system, many live TV channels may be multicast via satellite (IP-encapsulated or as conventional DVB digital TV) with stored video-on-demand transmission via the broadband connection. Arqiva’s Satellite Media Solutions Division suggests “IPTV works best in a hybrid format. For example, you would use broadband to receive some content and satellite to receive other, such as live channels”

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