London Underground gets emergency phone network

Airwave finally gets moving

The emergency services phone network, Airwave, was activated at 125 underground stations in London this morning, providing seamless coverage for service personnel working the tube.

Airwave is based on Tetra technology, providing cellular services for special handsets and (in theory) allowing emergency services to talk to each other from anywhere in the country, a service that now extends into the London underground system.

London has 125 sub-surface stations, and Airwave signed the £107m contract - including running costs until 2018 - back in January 2007, and started work in July of that year. The installation was pushed hard in response to the killing of Jean Charles de Menezes, and the following investigation, though how much difference it would have made is open to debate.

Tetra is capable of some quite clever things, with nodes acting as mesh routers to stretch coverage. Police occasionally use vehicle-mounted Airwave radios in that way, but no such complexity was needed for the tube deployment as London Underground was already in the process of deploying their own radio system - Connect - so they could communicate with staff. Airwave just piggybacked on that infrastructure to provide the back-haul.

The project was actually scheduled to switch on in March, but things went unusually well and the system became operational last month.

The systems are installed in the stations, but coverage projects down the tunnels too, so miscreants won't be safe anywhere. Still, Airwave is heavily biased towards voice, and has suffered accusations of being incapable of supporting the more data-centric applications such as throwing around video clips of criminals.

The rest of us still can't talk on the underground, obviously - unless we're in Hong Kong, where a technically almost identical underground network offers full connectivity to the commuting traveller. ®

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