March 20th, 2009 | 
Author: IPTV – OVERVIEW
What is IPTV?
The letters IPTV stand for internet protocol television, which is a technology for transporting data information and Audio and Video (AV), across an IP based digital network. This could include WAN, Ethernet LAN or internet. With the addition of set top boxes (STB), AV sources can be streamed across existing networks to TVs or PCs. IPTV can be one to one (Unicast) or one to many (Multicast).
The most successful form of transmission is offered by Multicast streams as the bandwidth can be shared amongst all of the users wishing to view that particular stream. Irrespective of the amount of viewers (providing the network is correctly configured), a 4Mbs stream for example, will only use that amount of bandwidth. No bandwidth is used if the channel is not being watched.
Unicast transmissions are most often used for two-way transmissions – for example Video On Demand (VOD), only the person who has ordered the content can receive it. Some control can also take place such as pause, play, rewind, fast forward etc. Unicast is used for linking buildings via a WAN for TV channels, cameras etc. The negative effect of unicast on the system is bandwidth, as each viewer uses their own amount. 100 users all viewing 4Mbs of VOD will use 400Mbs of the network’s bandwidth.
Why Use IPTV?
There are so many advantages over RF coaxial based transmissions. AV streams can simply be inserted into an existing network and viewed without addition to the existing infrastructure. Channels can be grouped and controlled to suit personal preferences. STBs can be controlled across the network or internet VOD servers. Sport, local content and films can be added for revenue stream in say a hotel, or offered free to a student campus. Streams can be recorded and viewed onto PCs without the need for extra cabling and television capture cards. This is useful for businesses, news agencies, banks etc.
Digital IP based networks are virtually immune to ghosting, noise, harmonics, cross modulation, reflections etc – problems that are often seen in analogue systems. Some of these problems have been resolved using digital transmission across the coaxial networks, however, these still suffer from some of the above.
So to summarise, the picture quality of a correctly installed IPTV system is better than almost all other means of transmission.
JJK runs Keydigital Productions a London Website Design Company and has used IPTV Technology and IPTV Products on many occasions.
Article Source: IPTV – Does It Live Up To The Hype?
