IPTV Technology - Overview
What is IPTV Technology?
IP TV stands for internet protocol television, which is a means of transporting Audio and Video ( AV ) and data information across a digital IP based network. This could include Ethernet LAN, internet, or WAN. AV sources can be streamed across existing networks to PCs or TVs with the addition of set top boxes ( STB ). IP Based TV technology can be one to many ( Multicast ) or one to one ( Unicast ).
Multicast streams offer the most efficient form of transmission as the bandwidth can be shared amongst all of the users wishing to view that particular stream, if the stream is say 4Mbs only that amount of bandwidth will be used irrespective of the amount of viewers (provided the network is configured correctly). If the channel is not being viewed no bandwidth is consumed.
Video On Demand - VOD Streaming - Video Technology
Unicast transmissions are generally used for two way transmissions for example, Video On Demand ( VOD ) this means only the viewer who has ordered the content receives it. Some control can also take place such as play pause, fast forward, rewind, 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. Each viewer uses it own amount, 100 users all viewing 4Mbs of VOD will use 400Mbs of the networks bandwidth.
Why Use IPTV Networks?
The advantages over RF coaxial based transmissions are many. 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 as to who views what. STBs can be controlled across the IPTV network or internet VOD servers with films sport local content can be added for revenue stream in say a hotel or free to a student campus. Streams can be viewed and recorded onto PCs with out the need for TV capture cards and extra cabling this is useful for banks, news agencies business etc.
Digital IP based networks are virtually immune to noise, ghosting, harmonics, cross modulation, reflections etc, and these problems 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.
