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 PCs or TVs. IPTV can be one to one (Unicast) or one to many (Multicast).
The most efficient 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 configured correctly), a 4Mbs stream for example, will only use that amount of bandwidth. No bandwidth is consumed if the channel is not being viewed.
Unicast transmissions are generally used for two-way transmissions – for example Video On Demand (VOD), only the viewer who has ordered the content receives it with this system. Some control can also take place such as pause, play, rewind, fast forward etc. Unicast can also be used for linking buildings via a WAN for cameras, TV channels 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 networks bandwidth.
Why Use IPTV?
There are many advantages over RF coaxial based transmissions. AV streams can simply be inserted into an existing network and viewed with no 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. Films, local content and sport can be added for revenue stream in say a hotel, or offered free to a student campus. Streams can be viewed and recorded onto PCs without the need for TV capture cards and extra cabling. This is useful for news agencies, businesses, banks, etc.
Digital IP based networks are virtually immune to ghosting, noise, harmonics, cross modulation, reflections etc – problems that are all common 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.
In brief the picture quality of a correctly installed IPTV system is superior to almost all other means of transmission.
Article source: Topmediatvip