This week sees the launch of O2's mobile phone coverage on platforms at five stations on the Glasgow Subway network - Buchanan Street, St Enoch, Partick, Hillhead and Govan.
As we've previously reported, O2 is the first mobile phone operator in the UK to use its "multi-user distributed antenna system" to enable mobile phones to work underground.
Derek McManus, O2's chief technology officer, said: "We're delighted Glasgow is leading the way with the launch of this new technology, particularly in time for the busy festive season".
"From today, shoppers in town will be able to phone or text friends and family about presents and meeting up, as well as arranging to meet for nights out or to alert family that that’s them on their way home".
"The new technology will enable customers to make calls, send and receive text messages and access a host of data services while on the Subway platform".