International Telecommunication Union   ITU
 
 
Site Map Contact us Print Version
 Monday, October 31, 2005
With the popularity of blogs, podcasting and web-based photo libraries, web content has become something much more accessible to the individual in the last few years. Now video looks set to be the next media to gain popularity with the new generation of home based media moguls.

Work on a new protocol that may spawn a whole new generation of independent broadcasters is underway at ITU. Relayed Multicast Protocol (RMCP) being developed by the ITU’s Study Group 17 uses something like a peer-to-peer model meaning that independent broadcasters no longer have to subscribe to a fat-pipe, instead relying on a collection of ‘peers’ or ‘relay agents’, in other words other people's computers. Peer to peer type traffic is reckoned to make-up as much as 72 per cent of current Internet traffic. And this figure is predicted to rise.

RMCP allows the live broadcast of video or audio piggy-backing off other users (or servers). So in a scenario where 100 people are demanding a live broadcast, instead of serving each one of these clients their own video stream, only one stream has to be provided and each user will be served from another in the network. This has significant implications for instance for businesses broadcasting live events, where a previous scenario demanded 100 users be fed individual feeds, RMCP allows the broadcast of just one.

Juyoung Park the editor of the ITU-T Recommendations says that RMCP allows for the efficient serving of hundreds of thousands of simultaneous connection requests.

Park says that the need for this type of protocol was identified by content providers. Standardization means that a single client can receive content from any number of suppliers.

An alternative solution – IP Multicast – is not applicable in today’s networks according to Park. For a start the success of IP Multicast would mean router upgrades throughout a network, something that many operators would balk at, especially given the unclear benefits of IP Multicast to their revenue streams.

Park says that tests by his organization – ETRI – have shown that speeds of 2 Mbit/s are possible. This reflects standard broadcast rates. However he says that typically users will experience something more like 640 Kbit/s. 

ITU-T has published one Recommendation (ITU-T Rec. X.603) on the topic outlining requirements, framework etc. The next two Recommendations due in 2006 will focus on the technical specifications. One focusing on one broadcaster to many clients, and the other on many broadcasters to many clients.