How the Olympic torch relay is broadcast live

Video caption, Covering a continuously moving object is no easy task and involves some new broadcasting ideas, as technology correspondent Rory Cellan-Jones has been finding out.
  • Author, Rory Cellan-Jones
  • Role, Technology correspondent

Here's my report explaining the technology behind the live broadcasting of the torch relay. Some 8,000 runners are carrying the torch over a total distance of 8,000 miles, and communities across the UK are already coming out on the streets in large numbers to join in the fun.

But broadcasting every minute of the event live on the web involves quite a major technological challenge. The pictures are beamed back not via satellite but over the 3G mobile phone network - and with the torch making its way through parts of the country where 3G coverage is patchy, some clever tricks have to be employed to make sure the screen doesn't go black. And, in an experiment which could point the way forward for live broadcasting of moving events, an unmanned aerial vehicle - or UAV - is on standby to beam pictures back from especially remote areas.

Click here for full coverage of the torch relay