01 Jun 2005
-
The ROFMOD system is tested at a TV studio in Teddington
Fibre optics and broad band radio have been brought together in a TV studio setting for the first time.
The star of the show is the ATC’s new wireless system that allows many cameras to be operated without clumsy, trailing cables. The same technology can be used for covert military communications between fixed and moving operators.
Project ROFMOD (Radio on Fibre mobile data network demonstrator) has solved the problem of moving cameras reasonably quickly and silently around the cluttered environment of a TV studio. Cables could soon be replaced by wireless links developed at the ATC, attached to the camera. These relay video signals into a fixed, fibre optic network that carries very broad bandwidth data. Freed of their burdensome connections, the camera operators can freely move around to get the best shooting positions.
The demands of high definition picture quality mean that TV cameras need lengthy, heavy cables that have to be manhandled in absolute silence by studio technicians. For fast moving action, this poses some real problems.
“As the cameras move around, the cables get in the way and make a swishing sound that interferes with the sound recording.” says Mohammed Nawaz, communications expert at the ATC. “The cables have to be carried around to keep them silent which limits the degree of movement. People carrying them also have to keep out of the shot” he says.
The ATC, together with partners from the broadcast technology industry, have solved the problem by designing a microwave transmitter that can send and receive signals over short distances between mobile cameras and fixed receivers in the studio ceiling. The receivers then pipe the signals along optical fibres without loss of quality, over many metres to the control room.
“The cameras have two way communication using 60 GHz – suitable for high bandwidth. The signals are short range – they only need to reach the fibre optic network in the ceiling - so they don’t interfere with the studio next door.” says Mohammed.
The ATC designed and patented a special, mushroom shaped antenna to do the job. Once safely encoded in the optical fibre, the signals can be relayed through great distances: kilometres if necessary, without risk of too much degradation or interference. Single frequency tests have been performed at TV Studios in Teddington to determine multi-path effects. Low bandwidth video link has been successfully demonstrated in the lab and further operational system tests are planned at the TV studio in the near future.
Four patents have resulted for BAE Systems from this work and the team are now working on ways to exploit the technology for military purposes. The unique mix of mobile, short range radio and long range fibre optic links that cannot be intercepted or degraded offers several potential battle field and platform applications. Amongst them are naval ship communications below and above deck, ship to ship links, and communications for rapid military deployments of vehicles with mobile Head Quarters.
Other ROFMOD partners are: Broadcast Project Research, Snell and Wilcox, and the University of Leeds. The project is part funded by the DTI LINK programme.
