In larger teleconference and videoconference suites, communication can suffer from ambient noise from participants’ activities, picked up by central microphones. A wireless microphone per person is desirable to avoid this, but conventional radio systems do not easily allow for the large numbers of separate channels – often more than a dozen – required in a licence-free band.
Revolabs created the concept of personal, small, tubular microphone units that would get over the problem of ambient noise but were looking for wireless communications expertise to be able to realise their concept in a commercially viable way.
Cambridge Consultants worked with Revolabs to determine the best radio technology to use: Bluetooth had originally been proposed. However, our advice was that DECT – a cordless telephone technology – could be adapted to deliver the wide-band audio performance and user density needed.
From Revolabs’ product concept we worked with them to create a detailed design specification, fully describing the function and user interface. We then designed and built prototype microphone boards to fit plastic enclosures designed by Revolabs, and an 8-channel receiver board. Our work included very compact RF hardware design and complex software value-engineered to run on the small embedded processor core of the DECT chip. After delivery of a number of systems, we supported hand-over to the manufacturer for volume production.
The Solo Executive microphone system was an immediate success in the market, not only for teleconferencing, but also in corporate governance where Solo can provide a multi-track audio output so that a transcriber can know exactly who said what in a meeting. Encryption of the digital signal provides security.
Around a hundred million DECT phones are sold globally each year, so the bill of materials for Solo is low. At the same time, DECT is specified for, and achieves, densities of more than 10,000 audio links per square kilometer, which means that multiple systems can co-exist within a suite of offices or meeting rooms.
Each microphone also has an earphone socket so that the user can hear the conference even when leaving the room, or receive simultaneous translation or other material.