Just one of a range of innovative and highly cost-effective antenna solutions from ERA Technology

BT Wholesale has launched a trial of mesh radio technology for the delivery of broadband services. The trial, using the Radiant Networks mesh radio solution, is giving BT an extended look at the technology in a real-life situation and allowing BT to explore its suitability to deliver broadband services in areas beyond the reach of ADSL. Radiant needed to ensure that the antennas for the system were as compact as possible, but no existing technology was capable of meeting the combination of performance, size and cost.

The antenna technology, the special manufacturing techniques and components used in the trial were developed by ERA for Radiant Networks. All of the participating premises, a mixture of homes and businesses, have a single antenna array, or node, which uses four of the ERA designed compact antennas, all concealed in a special ERA designed cover, with full freedom of ±360° rotation in the horizontal plane. The antennas are made from just two pieces of copper plated plastic. The manufacturing process is being patented by ERA.

“This development shows the skill that ERA has developed in designing cost effective antennas that can be manufactured in the real world,” stated Fred Cahill, Managing Director of ERA, “It’s just one of a number of highly innovative ideas that are in the process of being developed by ERA. We are also in discussions with a number of companies about other opportunities in broadband wireless generally.”

The Radiant system avoids the need for base stations by making every customer node part of the network infrastructure, transmitting to and receiving from other nodes allowing the signal to be automatically routed around obstacles eliminating line of sight problems. This approach removes the need for the large antennas and masts used to transmit to each individual customer in traditional point to multipoint wireless solutions.

As the trial progresses high speed internet will be added to the service for some participants. But at present video-on-demand has been chosen as the core content for the trial as its higher bandwidth demands will ensure the most robust test of the broadband delivery mechanism BT Wholesale is evaluating.

The trial covers an 80km² area around Pontypridd including Llantrisant, Beddau and Newtown Llantwit and surrounding villages. It will involve about 100 households in a mixture of urban, semi-rural and rural settings, many of which are outside the current reach of ADSL.

Technical background

The antenna allows the mesh system to have a bandwidth of about two GHz – nearly as wide as the advanced optical fibre telecommunication systems used in many cities. The radio frequency used by the system is 28 GHz. The antenna itself meets all ETSI requirements.

The design is based on a twist reflector, but places the feedpoint at the rear of the antenna, resulting in the total depth being only half of what would be expected using a conventional reflector.

Other ERA developments using the same antenna technology include automotive cruise control, where a 77 GHz development system is currently being trialled by a major car manufacturer.

About Radiant

Radiant was established in 1997 to develop and commercialise an innovative new Mesh fixed broadband wireless access technology. The first Radiant Mesh networks were deployed in 2001. During 1997-1999, Radiant raised US$10 million through private and institutional investors, which funded development of the technology. Advent Venture Partners, Intel Capital, executives of Kohlberg Kravis Roberts & Co and Sandler Capital Management raised a further US$20 million in 2000. This second round of financing was used in product development and to fund investment in sales and marketing. The recent third round funding provided Radiant with the working capital required to fulfil its substantial order book and ongoing development.