IPTV

Internet Protocol television (IPTV) is a system through which Internet television services are delivered using the architecture and networking methods of the Internet Protocol Suite over a packet-switched network infrastructure, e.g., the Internet and broadband Internet access networks, instead of being delivered through traditional radio frequency broadcast, satellite signal, and cable television (CATV) formats.
IPTV services may be classified into three main groups:
live television, with or without interactivity related to the current TV show;
time-shifted programming: catch-up TV (replays a TV show that was broadcast hours or days ago), start-over TV (replays the current TV show from its beginning);
video on demand (VOD): browse a catalog of videos, not related to TV programming.
IPTV is distinguished from general Internet-based or web-based multimedia services by its on-going standardization process (e.g., European Telecommunications Standards Institute) and preferential deployment scenarios in subscriber-based telecommunications networks with high-speed access channels into end-user premises via set-top boxes or other customer-premises equipment.

 

Definition

Historically, many different definitions of IPTV have appeared, including elementary streams over IP networks, transport streams over IP networks and a number of proprietary systems.
The official definition approved by the International Telecommunication Union focus group on IPTV (ITU-T FG IPTV) is as follows:
"IPTV is defined as multimedia services such as television/video/audio/text/graphics/data delivered over IP based networks managed to provide the required level of quality of service and experience, security, interactivity and reliability."
Another official and more detailed definition of IPTV is the one given by Alliance for Telecommunications Industry Solutions (ATIS) IPTV Exploratory Group on 2005:
"IPTV is defined as the secure and reliable delivery to subscribers of entertainment video and related services. These services may include, for example, Live TV, Video On Demand (VOD) and Interactive TV (iTV). These services are delivered across an access agnostic, packet switched network that employs the IP protocol to transport the audio, video and control signals. In contrast to video over the public Internet, with IPTV deployments, network security and performance are tightly managed to ensure a superior entertainment experience, resulting in a compelling business environment for content providers, advertisers and customers alike."
One definition for consumer IPTV is for single or multiple program transport streams (MPTS) which are sourced by the same network operator that owns or directly controls the "last mile" to the consumer's premises[citation needed]. This control over delivery enables a guaranteed quality of service (QoS), and also allows the service provider to offer an enhanced user experience such as better program guide, interactive services etc.
In commercial environments IPTV is widely deployed for distribution of live TV, video playout channels and Video on Demand (VOD) material across LAN or WAN IP network infrastructures, with a controlled QoS.