It's the one place where you can escape the constant chatter and clicking of keypads, but from 2012, the London Underground just might have its very own mobile phone network.That's the plan of London mayor Boris Johnson anyway. According to Pocket Lint (quoting the City AM newspaper), Johnson is nearing agreement with all the major mobile networks to have a 'network signal on the entire Tube network by the time the Olympics come to London in 2012'.Cost, as you might expect, is the issue. The authorities hope Vodafone, Orange, O2, T-Mobile and 3 would bare the cost of installing the network rather than the London Underground or the capital's taxpayers.With that in mind, nothing has yet been signed. According to City AM, the Greater London Authority has said that a solution: 'remains dependent on the market providing a credible proposal that satisfies both technical and commercial considerations'.In the meantime, just think of that descent down the escalator as a brief period of tranquility rather than a disruption to your working day or social life. One day you might appreciate it as such.