The emergency Airwave radio service used to provide communication in the event of a tube disaster may not be as reliable as many believe, the London Assembly has warned.

The Airwave service supplied by O2 was installed into the underground this year to ensure that a repeat of July 7 2005, where firemen, ambulance crew and police officers were unable to use their radios in the underground tunnels, was not repeated.

It runs off the TETRA radio signal and claims to give communication access to emergency services in deep underground tunnels by piggy backing off London undergrounds Connect digital radio system.

However, according to Richard Barnes chair of the London Assembly, “there are [still] gaps in the service.”

“Airwave is getting rolled out but it is not the 100 percent service people thought,” he said.

This is because the original contract between Airwave and the Government specified in some cases that the service would only be implemented at ground level.

“In order to ensure that the whole of the underground is covered booster aerials are needed in some stations,” he added.

Although the Government haven’t said no to the additional boosters Barnes believes the additional cost to put these in will cause discussions and lead to delays.

He also shared fears that that in some cases the service wouldn’t be able to be accessed in some buildings including police stations because the signals could be blocked by other buildings.

Rupert Cazalet, head of stakeholder relations at Airwave agreed that more needed to be done about this,

“We are aware that there have been concerns of insufficient coverage in buildings which is something that affects all radio communications. We are w orking with the Metropolitan police to identify what can be done to improve this.”

However, he disagreed that the service would be affected on the London Underground,

“As long as the Connect service is working so will Airwaves,” he told Computeractive.

However with London underground admitting that there is no back up in place for the Connect system this could be a worrying comment

“The Connect system is very robust and it is extremely unlikely that it will completely fail,” a London underground spokesman said when Computeractive asked about back up plans. This, he said, was because of the way the network was set up.

“If one part of the connect cable gets damaged then the energy will move to another part of the networked hubs,” of which there are many, he said.

The rollout, which is ready being rolled out, will link 125 stations to the Airwaves and Connect system and will aim to provide police forces with underground radio access from 2008.