Over the last decade, the growth of satellite service, the rise of digital cable, and the birth of HDTV have all left their mark on the television landscape. Now, a new delivery method threatens to shake things up even more powerfully. Internet Protocol Television (IPTV) has arrived, and backed by the deep pockets of the telecommunications industry, it's poised to offer more interactivity and bring a hefty dose of competition to the business of selling TV.

Description of Internet Protocol Television

IPTV describes a system capable of receiving and displaying a video stream encoded as a series of Internet Protocol packets. If you've ever watched a video clip on your computer, you've used an IPTV system in its broadest sense. When most people discuss IPTV, though, they're talking about watching traditional channels on your television, where people demand a smooth, high-resolution, lag-free picture, and it's the Telco's that are jumping headfirst into this market. Once known only as phone companies, the Telco's now want to turn a "triple play" of voice, data, and video that will retire the side and put them securely in the batter's box.

In this primer, we'll explain how IPTV works and what the future holds for the technology. Though IP can (and will) be used to deliver video over all sorts of networks, including cable systems.First things first: the venerable set-top box, on its way out in the cable world, will make resurgence in IPTV systems. The box will connect to the home DSL line and is responsible for reassembling the packets into a coherent video stream and then decoding the contents. Your computer could do the same job, but most people still don't have an always-on PC sitting beside the TV, so the box will make a comeback. Where will the box pull its picture from? To answer that question, let's start at the source.Most video enters the system at the Telco's national head end, where network feeds are pulled from satellites and encoded if necessary (often in MPEG-2, though H.264 and Windows Media are also possibilities). The video stream is broken up into IP packets and dumped into the Telco's core network, which is a massive IP network that handles all sorts of other traffic (data, voice, etc.) in addition to the video.


IPTV uses the switched digital video architecture. That enables users to customize their viewing by removing the restrictions of channel based Surfing. IPTV sends only one program at a time. When a viewer changes a channel or selects a program, a new stream of content is transmitted from the provider’s server directly to the viewer’s set-top box. The promise of IPTV lies in its switched digital video architecture. IPTV primarily uses multicasting with Internet Group Management Protocol (IGMP) version 2 for Real Time Streaming Protocol for on-demand programs. Compatible video compression standards include H.264, Windows Media Video 9 and VC1, DivX, XviD, Ogg Theora and the MPEG-2and 4.

Wide Area Distribution Networks

The Wide Area Distribution Network is made up of distribution capability, capacity, and quality of service. It also consists of other capabilities, such as multicast, which is necessary for the reliable and timely distribution of IPTV data streams from the service nodes to the customer premises. Moreover, the core and access network cover the optical distribution backbone network and the various digital subscriber line access multiplexes (DSLAMs). This is located at the central office or remote distribution points.


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