IPTV (Internet Protocol Television) is a system where a digital television service is delivered using Internet Protocol over a network infrastructure, which may include delivery by a broadband connection. A general definition of IPTV is television content that, instead of being delivered through traditional broadcast and cable formats, is received by the viewer through the technologies used for computer networks.
Internet Protocol Television (IPTV) is digital television delivered on your television (and not PC) through high-speed Internet (broadband) connection. In this service, channels are encoded in IP format and delivered to the TV through a set-top box. IPTV service also includes video on demand, which is similar to watching video CDs/DVDs using a VCD/DVD player. For residential users, IPTV is often provided in conjunction with Video on Demand and may be bundled with Internet Services, such as Web access and VoIP. The commercial bundling of IPTV, VoIP and Internet access is referred to as ‘Triple Play’ service (when these three are offered with mobility, the service is referred to as ‘Quadruple Play’).
Working of IPTV
IPTV converts a television signal into small packets of computer data, like any other form of online traffic, such as email or a web page.
There are three main components of IPTV. First, the TV and content head end, where the TV channels are received and encoded and also other content, like videos which are stored.
The second component is the delivery network, which is broadband and landline network provided by a telecom operator, such as MTNL.
The third component is the set-top box, which is required at the customer location. The packets are reassembled into programing by software in the set-top box. This box is connected between the operator’s broadband modem and customer’s TV.
IPTV covers both live TV as well as stored video (Video on Demand VOD). The playback of IPTV requires either a personal computer or a set-top box connected to a TV. Video content is typically compressed using either an MPEG-2 or an MPEG-4 codec. The newly released (MPEG-4) H.264 codec is increasingly used to replace the older MPEG-2 codec.
In standard-based IPTV systems, the primary underlying protocols used are as follows:
1. Live TV uses IGMP version 2 or IGMP version 3 for IPv4 for connection to a multicast stream (TV channel) and for changing from one multicast stream to another (TV channel change).
2. VOD is using the Real Times Streaming Protocol (RTSP).
Advantages of IPTV
1. The IP-based platform offers signification advantages, including the ability to integrate television with other IP-based services, like high-speed Internet access and VoIP. The quality of digital video and audio is much better compared with the traditional analogue TV. With additional features, it can become interactive. For example, viewers may be able to look up a player’s history while watching a game.
2. They also may be able to schedule a recording of their favourite programme when they are not home. With video on demand, they can browse an online movie catalogue and watch the movies instantly. Because IPTV uses standard networking protocols, it promises lower costs for operators and lower prices for users. Using set-top boxes, video can be streamed to households more efficiently (as only the requested channels are transmitted to the user) than cable (where all channels are transmitted to the user and the choice is made at the user’s end).
3. Another advantage of an IP-based network is the opportunity for integration and convergence. This opportunity is amplified when using IMS-based solutions. Converged services implies interaction of existing services in a seamless manner to create new value added services. One good example is On-Screen Caller ID, getting Caller ID on your TV and the ability to handle it (send it to voice mail, etc.).
4. IP-based services will help to enable efforts to provide consumers anytime-anywhere access to content over their televisions, PCs and cell phones and to integrate services and content to tie them together. Within businesses and institutions, IPTV eliminates the need to run a parallel infrastructure to deliver live and stored video services.
Limitations of IPTV
1. Because IPTV is based on Internet protocol, it is sensitive to packet loss and delays if the IPTV connection is not fast enough.
2. IPTV uses a two-way digital broadcast signal sent through a switched telephone or cable network by way of a broadband connection and a set-top box programed with software (much, like a cable or DSS box) that can handle viewer requests to access to many available media sources. It needs new hardware in the form of set-top box. But this is a one-time investment.
3. Privacy issues need to be resolved as the service provider knows the channels viewed by the end user.