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The IPTV Revolution
|11 ноября 2008|
New Opportunities, New Challenges For Satellite Communications Systems by Thomas Parish, Vice President, Globecomm Systems.
Advances in technology, improvements in communications infrastructure, and growing user demand are driving toward the creation of a single, common digital medium. It will be a unified global platform capable of enabling transmission of digital information in virtually any form across broadband networks. We call it digital convergence.
While the term has been used (and perhaps misused) for years, it is clearly the right term for the revolutionary paradigm shift that is taking place in the telecommunications world today.
With the advent of Internet protocol television (IPTV), the vision of a universal communications platform is quickly becoming a reality. The convergence of IP-based content delivery networks with traditional voice and data communications is creating exciting new services in multiple markets. In the coming years, consumers will enjoy access to customized content, rich applications, and personalized interactive entertainment in homes, automobiles, and hand-held devices, all enabled by IP-based communication networks.
While a cable network transmits all channels to each user, the IPTV network transmits only the channels the viewer is actually watching. That means an IPTV network can offer an effectively unlimited number of channels. The number of channels that can be offered on a cable network, however, is limited by the 850 MHz spectrum allotted on its hybrid fiber coax plant. In order to provide unlimited channels, hundreds of video program channels must be aggregated and made available for distribution to the subscriber.
This lends itself well to point-to-multipoint distribution over satellite. That is, a central content receive site or “IPTV Super Headend” will aggregate content from satellite downlinks and then distribute that content to local access points or regional headends over IP all the way to the subscriber.
Building an IPTV Super Headend can impose a high capital expenditure burden as multiple antennas are required to receive existing video content from multiple satellites across the satellite arc. Each video stream must be transmitted in its own self-contained single program transport stream (SPTS) as opposed to a multi program transport stream (MPTS). Each channel must be received, decoded, de-encrypted, and then encoded, encrypted and IP-encapsulated for distribution to the regional sites. With hundreds of channels and redundancy, the cost for a large IPTV Super Headend can exceed 20 million dollars.
As a solution to the issues described above, companies including SES Americom with its IP PRIME service and Intelsat with its Ampiage service are building IPTV Super Headends and offering pre-packaged, bundled, programming to the telephone companies.