Optical encoding secures wireless communications
Engineers at a QinetiQ naval-communications test and evaluation facility at Portsdown in Hampshire are reporting “significant benefits” from the recent installation of an Azdec optical mobile local communications (MLC) system designed and developed by Link Microtek.
The communications development and integration facility (CDIF) is equipped with an array of radio systems, simulators and analysers, enabling it to emulate almost any ship’s communication system for purposes such as R&D, capability assurance and operational support.
The CDIF is divided into two rooms, one housing racks of equipment and the other primarily functioning as a control room, needing constant communication between the two locations.
Paul Netting, QinetiQ’s maritime comms and networks team lead, explains: “Because of the nature of the work we do here, we cannot use an RF-based system of any kind for mobile local communications as the whole building has to be protected from inadvertent leakage of transmissions. Originally we had to either walk from room to room or reel out a telephone extension cable, which was obviously inconvenient and also presented a trip hazard.”
Since it employs optical encoding technology, the Azdec system provides QinetiQ personnel with totally secure, interference-free voice communications while allowing them to roam around the CDIF building, unhindered by any trailing wires. There are no RF emissions and the signals cannot be intercepted by any conventional method, so it is impossible for anyone to jam the transmissions or eavesdrop on what is being said.
This also means that the system can operate anywhere within the building without compromising the facility’s red/black communications demarcation. “The optical transmissions cannot couple to other items of equipment, so security is assured regardless of whether the operator is in the red or black area,” says Netting.
The eight-channel Azdec system in the CDIF comprises a compact base station, 14 fixed infra red (IR) antennae, eight binaural headsets, 16 operators’ belt-mounted battery-pack/control units, and a central battery-charger unit.
As well as setting up separate user groups on the different channels, QinetiQ has also tightly integrated the Azdec installation with the CDIF’s VoIP system and configured it so that an engineer standing in front of an equipment rack can use the Azdec headset for an external phone call or even for speaking directly to personnel on a ship at sea. The binaural headset enables the engineer to hear internal comms in the left earpiece while external comms are fed to the right-hand side.
The optical digital encoding technology at the heart of the Azdec system is immune to radio, radar and electrical noise – even severe energy pulses – and has no effect on sensitive electronic equipment. It also carries a Class 1 product designation as defined by the EN 60825-1 standard, which means it presents no ocular or other health hazard to users.
