BT Developes New Technology Tripling Satellite Communication Links Capacity


Development by BT of satellite modulation technology with more power to maximise the use of expensive bandwidth


-/25 Oct, 2004 - Wi-Fi Technology News/-BT has developed new technology that can triple the capacity of existing satellite communication links. The technology only has to be deployed in the ground stations, hence upgrading existing systems is both straightforward and efficient.

Satellite communication now accounts for around 10 per cent of global telecommunications revenues [1] and global demand for satellite-based Internet circuits is predicted to approximately double between 2005 to 2010 [2] therefore the technology is poised to enable significant cost reductions in this fast-growing global market.

Development of the system was prompted by the relative high costs involved in leasing satellite bandwidth capacity. This is an issue affecting any organisation that delivers data over a satellite link. By putting more data over the same amount of bandwidth, the new modulation technique invented ensures a two to three times greater efficiency, thus enabling more information to be delivered at the same cost.

The new modulation scheme draws on similar principles to those used in the signal transmitted by GSM phones - which delivers data over a modulation scheme consisting of two states - this new method uses multiple states, combined with partial response signalling. Its unique innovation lies in the design of the detection mechanism in the demodulator, which is based on symbol pattern recognition.

The system has been designed for use over large-scale satellite links operating from earth stations, which typically carry high bandwidth data. These include ISP backbone connections, satellite newsgathering, video links and corporate use, military satellite communications and international trunk traffic being transmitted across continents.

Mike Carr, director of research and venturing, BT Group CTO said: "Seeing the big growth in ISP backbone connection by satellite some two years ago, especially from the UK and USA to Middle and Far Eastern countries, we were prompted to develop a technology to help maximise the use of bandwidth, and so reduce cost. Satellite is a particularly useful delivery method for asymmetrically delivered data, whereby more data is needed to be delivered than received from a given destination. As such, the new modulation scheme has a particularly significant role to play in this market."

Further development of the technology for delivering data to 'small dish' services, such as home-based satellite TV is under consideration.
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[1] Telecommunications Fixed Satellite Services US Equity Research, Credit Lyonnais Securities

[2] Mark Williamson, Internet-over-satellite: backbone or spare rib? Telecommunications International, November 2002.

About BT: http://www.btplc.com