Cambridge Consultants has completed initial trials with Iridium Communications Inc of new key components of the world's largest push-to-talk (PTT) radio system - the US Department of Defense (DoD) Distributed Tactical Communications System (DTCS).

DTCS enables soldiers in isolated areas to communicate without the need for ground infrastructure - and in locations where they often can't pick up a geostationary satellite's signal unless they move to higher ground.

The "netted" group call communication system - involving listeners in designated user "nets" - provides over-the-horizon, beyond line-of-sight tactical networks. Soldiers in remote combat zones or disaster areas are able to use lightweight handheld PTT radios to exchange mission-critical data with command centers across the globe, at the touch of a button.

Cambridge Consultants is delivering key new technology elements for DTCS. Ongoing development is extending existing capabilities to allow voice and data to be transmitted and received from any location worldwide, for unrivalled tactical and operational use.

Using its unique knowledge of the Iridium system, as well as commercial PTT services, Cambridge Consultants has developed radio transceiver electronics for DTCS handheld radios, as well as gateway infrastructure to support the DTCS service.

Both of these elements are critical to the success of the system, with the gateway element ultimately targeting a "five nines" (99.999%) reliability rating, to ensure that soldiers have service when they need it most.

"Cambridge Consultants has a proven track record of developing technically challenging and 'mission critical' communications technologies, and bringing them to operational readiness quickly," said Iridium executive vice-president for government programs Lt. Gen John Campbell (USAF-Ret).

"As a result, we did not hesitate in selecting Cambridge Consultants as our technology partner for this project, and have every confidence in the company's ability to develop the electronics and software efficiently, while still adhering to the stringent requirements necessary for success."

The new technology developed by Cambridge Consultants includes advanced software radio functionality that will provide multiple receiver capability and rapid synchronization to Iridium satellites to enhance PTT connection speed and call quality. In addition, new encrypted bearer channels support encrypted communication within groups.

Richard Traherne, head of the wireless division at Cambridge Consultants, said, "We have been working with Iridium since 2003 as its design partner, and are excited to be extending our long-term relationship on this groundbreaking project.

With one of the largest independent teams of wireless product developers in the world, we combine in-depth experience of mainstream communications with our unique Iridium system knowledge, to develop compelling products for Iridium's clients. We look forward to supporting Iridium and its client - the US DoD - in launching the largest global PTT network."