Communications minister Lord Carter has put the idea of mobile coverage on the London Underground back on the government agenda, only months after it was revealed that a planned Tube mobile trial had been shelved indefinitely.
Back in March, ZDNet UK's sister site, silicon.com, revealed that Transport for London (TfL) had quietly dropped plans for a six-month mobile Tube trial. The pilot, which was to have considered whether it would be technically and commercially viable for coverage to be extended across the entire Underground network, was shelved after TfL said it had not received any commercially "credible" proposals from the market.
However, in the government's Digital Britain report, unveiled on Tuesday, Lord Carter said there is a need to address "notable gaps" in mobile coverage on transport networks.
"There is a near total mobile-coverage blackout over the Central London section of the London Underground, including even large stations," the report notes.
To plug blackspots, the report encourages mobile operators and the Mayor of London to work together to extend mobile broadband coverage to the Tube.
In Carter's view the London Olympics is an ideal opportunity to digitise the Underground.
"The London Olympics in 2012, which will be the most digital Olympics in history, seems a particularly good reason for the mobile network operators to work with the Mayor of London to provide and fund solutions to take the initiative to improve the broadband mobile access for mobile customers travelling by Tube — including the huge influx of international visitors to the London Olympics," the report states.
It adds the government is willing to address any regulatory or "similar constraints" that might be acting as a barrier to an Underground deployment.
However, technical issues are likely to be a more immediate constraint, according to TfL's chief information officer, Phil Pavitt, who told silicon.com: "Mobiles on the Tube will be a tough challenge. Some of the tunnels are exceptionally deep, and there is the question of what level of service do you guarantee?
"Because of the technical challenge, the financial costs are quite high so businesses have to think financially and ask 'is there a model where customers really want this?'."
A TfL spokesman added however that its position on a mobile rollout remains unchanged. "We at the moment don't have anyone coming to us with a commercially viable solution," he said.
Nevertheless, Pavitt believes the Tube will have mobile coverage one day: "I believe it will happen at some stage but the timing remains a big question," he said.
A TfL spokesman added: "Naturally if funding was found from external sources we would give consideration to how a system might be implemented on the Tube."
The emergency services have a Tetra comms network on the Underground, supplied by Airwave. However in a recent interview with silicon.com, Airwave chief executive Richard Bobbett said the economics of a commercial mobile Tube rollout fall between two stools.
"With call rates being challenged the way they are [mobile operators] probably don't have the luxury now to fund those types of installations, so they would look for someone like TfL to fund it themselves. Well, what commercial gain does TfL get from you using your mobile phone?" he said.
Carter's Digital Britain report also flags up other transport comms gaps which he believes need plugging — noting there has been a failure to provide "reliable and consistent" mobile broadband coverage on the UK's railway network.
The report adds the government is looking at "cost-effective" ways to support railway rollouts — with one possible option being to make high-speed broadband services part of the rail franchise requirements for train operators.
Another option on the table is integrating broadband into Network Rail's next funding round, according to the report.
"Further discussions will also be held with Network Rail to ease access to Network Rail land for commercially based services," it adds.