Wide-ranging improvements for licence-free digital wireless audio

New technology platform from Cambridge Consultants for the wireless delivery of high-quality audio

Hundreds of millions of DECT products are sold annually – the DECT wireless standard is the basis for more than 80% of cordless telephones worldwide, as well as things like intercoms, hearing assistance systems and simultaneous translation facilities. DECT is robust with a dynamic channel allocation scheme, moving seamlessly to a new channel if it encounters interference. But, until now, the technology has had some limitations. While it worked very well in standard office buildings and homes, in very large enclosed spaces its range was limited because of interference as a result of multipath propagation – the radio equivalent of reverberation.

The new platform from Cambridge Consultants resolves these issues. The ‘large space’ problem has been solved using a low-cost signal processor and some innovative integration with state-of-the-art low-cost DECT silicon. Advanced low-latency audio codecs have also been developed so that stereo or mono full-bandwidth audio can be transmitted. Unique to Cambridge Consultants is the use of DECT to broadcast from one frequency-agile central unit to multiple receivers for distribution. The receivers automatically provide signal-quality feedback so that the central unit can move channel seamlessly when needed.

“As well as providing reliable communications, DECT has another feature unique at its cost level,” said Tim Whittaker, System Architect at Cambridge Consultants. “The DECT standard includes seamless cell handover functionality as a mandatory feature, so all DECT chips can do it. This means that a radio microphone, intercom or distribution system can be provided with multiple base stations, and automatically connect to the one offering the best performance.”

Cambridge Consultants has developed distributed software that will run on a number of DECT base stations, and manage the entire handover process between them. This functionality is transparent to the ends, so that the audio source – or mixing desk or intercom system in the middle – need have no special provision for a wireless device. In radio engineering terms, this is like providing an unlimited number of diversity antennas, so that you need never lose connection wherever you go.