As described in Ref. , IPTV deals with approaches, technologies, and protocols to deliver commercial-grade SD and HD entertainment-quality real-time linear and on-demand video content over IP-based networks, while meeting all prerequisite QoS, QoE, Conditional Access (CA) (security), blackout management (for sporting events), Emergency Alert System (EAS), closed captions, parental controls, Nielsen rating collection, secondary audio channel, picture-in-picture, and guide data requirements of the content providers and/or regulatory entities. Typically, IPTV makes use of MPEG-4 encoding to deliver 200–300 SD channels and 20–30 HD channels; viewers need to be able to switch channels within 2 s or less; also, the need exists to support multi-set-top boxes/multiprogramming (say 2–4) within a single domicile. IPTV is not to be confused with the simple delivery of video over an IP network (including video streaming) that has been possible for over two decades; IPTV supports all business, billing, provisioning, and content protection requirements that are associated with commercial video distribution. IP-based service needs to be comparable to that received over cable TV or Direct Broadcast Satellite. In addition to TV sets, the content may also be delivered to a personal computer. MPEG-4, which operates at 2.5 Mbps for SD video and 8–11 Mbps for HD video, is critical to telco-based video delivery over a copper-based plant because of the bandwidth limitations of that plant, particularly when multiple simultaneous streams need to be delivered to a domicile; MPEG-2 would typically require a higher bitrate for the same perceived video quality. IP Multicast is typically employed to support IPTV. There has been significant deployment of commercial-grade IPTV services around the world in the recent past, as seen in Table 5.1.
One can anticipate several phases in the deployment of IPTV, as follows:
- Phase 1: IPTV introduced by the telcos for commercial delivery of entertainment-grade video over their IP/MPLS (Multiprotocol Label Switching) networks (2007–2012).
- Phase 2: IPTV introduced by the cable TV companies for commercial delivery of entertainment-grade video over their cable infrastructure (speculative, 2012+).
- Phase 3: IPTV to morph to Internet TV for commercial delivery of any video content but of entertainment-grade quality over the Internet/broadband Internet access connections (2012+).