IPTV Over a Satellite Based Network

IP is also emerging as a preferred method of distributing video content via satellite links. Satellite links can provide higher bandwidth than terrestrial transmission networks and are starting to get used for IP based triple-play services that comprise of digital video content, VoIP, and high speed Internet access.
Many of the satellite network providers have started to use their satellite based networking platforms to deliver IP video content to cable and telecommunication headends and IPTV data centers. The networking infrastructure used to support this mechanism of IPTV distribution is shown in Fig. 2.8.
A fully rounded end-to-end satellite centric IPTV distribution system As shown the original content is received, aggregated, encoded in MPEG-2,MPEG-4, or Windows Media format and encrypted at the satellite operator’s video operations center. Once processed at the operations center, the content is uplinked to a satellite and relayed back down to various video hubs. These video hubs are generally operated by cable or telecommunication companies and use their own existing networking infrastructure to deliver IPTV services to residential subscribers.With regard to delivering IPTV services directly to consumers a number of options are currently available.
Deploy Hybrid Satellite IP Set-top Boxes The deployment of hybrid satellite IP set-top boxes allows consumers to access traditional satellite services via the satellite link and IPTV services via a standard broadband connection.
Utilize Standard IP Set-top Boxes This model involves the delivery of programming channels using standard satellite transmission techniques to large housing developments, converting the channels to IP, and streaming to IP set-top boxes.
Provide Subscribers with Set-top Boxes That Include a Hard Disk The large bandwidth capacity requirements of delivering on-demand content makes IP-VoD based applications for most satellite systems impractical. However, some satellite service providers have started to circumvent the limitations of satellite based delivery systems by deploying set-top boxes that incorporate a hard disk. Once installed at the subscribers home, the IP-VoD content is automatically downloaded to the hard disk. This allows IPTVend users to view the content at their own convenience.
Use Satellite Broadband Modems Broadband modems may also be used to deliver satellite IPTV services. These modems generally comply with one of three international standards:

(1) IP over satellite (IPoS) This standard has been ratified by U.S. based Telecommunication Industry Association (TIA) and ETSI. It utilizes a technology called DVB-S2 (please refer to Chapter 5 for specific details on DVB-S2)and supports data throughputs of up to 120 Mbps.

(2) DVB return channel via satellite (DVB-RCS) DVB-RCS was developed by European based DVB. It defines a forward-link data transmission rate of 40 Mbps and a return channel capacity of approximately 2 Mbps. DVB-RCS is officially defined in ETSI EN 301 790.

(3) DOCSIS over satellite This mechanism for transmitting IPTV content over a satellite link is based on an adapted version of the DOCSIS standard. The main difference between cable DOCSIS and satellite DOCSIS is the use of the Quadratare Phase Shift Keying (QPSK) modulation scheme instead of the QAM, which has been designed for HFC networks. Early versions of the protocol provide support for speeds of 1.5 Mbps, whereas newer versions can achieve much higher data rates. These newer rates mean that satellite operators can start to leverage IP based technologies to deliver video content across their networks.