3G Networking Technologies

Mobile networks based on 3G technologies such as EV-DO and HSDPA are also capable of delivering a range of mobile IPTV applications.

EV-DO Evolution-Data Optimized (EV-DO) is a wireless radio broadband data standard that boosts maximum data rates up to 4.9 Mbits/s.

HSDPA High-Speed Downlink Packet Access (HSDPA) supports rates up to approximately 14 Mbps on the downstream path, with higher speeds planned in the future.

Although not an ideal platform for delivering IPTV services, EV-DO and HSDPA do provide network operators with the ability to deliver IPTV services to consumers who live in areas that are poorly served by DSL and cable broadband systems.
Since the invention of television, a number of different distribution technologies have been developed to deliver signals to consumers around the world. Until recently, there were five primary networking platforms used to distribute TV content, namely, wireless off-air, satellite, DSL, fiber and cable TV networks. In more recent times a new platform has emerged that also allows consumers to view broadcast and on-demand video content the Internet.
Improved broadband speeds combined with advances in compression technologies and greater viewing choices are some of the reasons why consumers have started to increasingly turn to the Internet for video entertainment over the last couple of years. IPTV over the Internet is available in a number of formats.

Streamed Internet TV Channels
The delivery of TV channels over the Internet is a popular IPTV application and involves the streaming of video content from a server to a client device, which is  capable of processing and disp laying the video content. The type of device used toview Internet TV channels is typically a PC or a media center PC. StreamedInternet TV channels can however also be accessed via a mobile phone or an IP set-top box. The content available via streamed Internet TV channels is delivered in real time, and the viewing experience mimics the traditional approach to TV viewing, namely, a channel is chosen and viewing commences immediately. The technical process of streaming an Internet TV channel usually starts at the streaming server where the video content is broken into multiple IP packets,compressed, and then transmitted or streamed across the Internet to the client PC.
The PC includes software, typically a browser, which decompresses the videocontent and generates a live video feed. The time period between selecting a TV channel and the commencement of viewing is generally quite short and depend s on the connection speed that is available between the client and the server. A highly simplified graphical view o f a networking architecture used to deliver a single streamed TV channel over the Internet is presented in (Fig. 2.12).In all Internet TV channel deployments a streaming server is required. Inaddition to playing out video content upon request from an IPTV subscriber, a standard streaming server will also support the following functions:

. Storing and retrieving source video content.

. Controlling the rate at which the IP video packets are delivered to the client
viewing device.

. Executing forward and back commands as requested by the Internet TV viewer.

A single streaming server works fine for delivering a small number of Internet TV channels to a limited number of users. To support the delivery of multiple channels to thousands and possibly hundreds of thousands of IPTV subscribers, a number of streaming servers need to be deployed in different parts of the network.
From a security perspective the streaming of video content is quite secure because the material is not stored on the client’s access device. Thus, unauthorized copying of content is prohibited. Other benefits of this avor of IPTV include itsability to operate effectively over low bandwidth connections and viewers have theability to start watching content at any point in the IPTV stream.
What separates the delivery of Internet TV with the other delivery mechanisms discussed in this chapter is the fact that Internet portal sites do not own or control the underlying infrastructure used to stream IP video services to Internet users. The networking infrastructure is generally owned by either cable TV providers or telecommunication companies.