IPTV (Internet Protocol Television) is a system where a digital television service is delivered using InternetProtocol over a network infrastructure, which may include delivery by a broadband connection. A general definitionof IPTV is television content that, instead of being delivered through traditional broadcast and cable formats, isreceived by the viewer through the technologies used for computer networks.
For residential users, IPTV is often provided in conjunction with Video on Demand and may be bundled with Internetservices such as Web access and VoIP. The commercial bundling of IPTV, VoIP and Internet access is referred toas "Triple Play" service (adding mobility is called "Quadruple Play"). IPTV is typically supplied by a service providerusing a closed network infrastructure. This closed network approach is in competition with the delivery of TV contentover the public Internet, called Internet Television. In businesses, IPTV may be used to deliver television contentover corporate LANs.
It is important to note that historically there have been many different definitions of "IPTV" including elementary streams over IP networks, transport streams over IP networks and a number of proprietary systems. Although (in Mid 2007) it is premature to say that there is a full consensus of exactly what IPTV should mean, there is no doubt that the most widely used definition today is for single or multiple program transport streams (MPTS) which are sourced by the same network operator that owns or directly controls the "Final Mile" to the consumer's premises.Fact|date=April 2008 This control over delivery enables a guaranteed quality of service, and also allows the service provider to offer an enhanced user experience such as better program guide, interactive services etc.
While all major western countries and most developed economies have IPTV deployments, the world's leading markets for IPTV for now are France (led by Free, then Orange, then Neuf; total of over 4 million subscriptions), South Korea (1.8 million subscriptions), Hong Kong, Japan, Italy, Spain, Belgium, China, Switzerland and Portugal. Services have also launched in Scandinavia and, with two competing players, Iceland. The United Kingdom launched IPTV early but has been slow to grow. IPTV is just beginning to grow in Central and Eastern Europe,now it is growing in South Asian countries such as Sri Lanka and especially India. but significant plans exist in countries such as Poland and Russia
The IP-based platform offers significant advantages, including the ability to integrate television with other IP-basedservices like high speed Internet access and VoIP.
A switched IP network also allows for the delivery of significantly more content and functionality. In a typical TV orsatellite network, using broadcast video technology, all the content constantly flows downstream to each customer,and the customer switches the content at the set-top box. The customer can select from as many choices as thetelecomms, cable or satellite company can stuff into the “pipe” flowing into the home. A switched IP network worksdifferently. Content remains in the network, and only the content the customer selects is sent into the customer’shome. That frees up bandwidth, and the customer’s choice is less restricted by the size of the “pipe” into the home.This also implies that the customer's privacy could be compromised to a greater extent than is possible withtraditional TV or satellite networks. It may also provide a means to hack into, or at least disrupt (see Denial ofService) the private network.