St. Pancras has the weakest mobile phone signal and Three offers the most reliable network for making calls while on the train, research suggests.
Global Wireless Solutions (GWS) measured the best and worst places for phones to browse the internet and make voice calls on ten of the most popular commuting routes in and around London.
Routes included Charing Cross to Sevenoaks, Charing Cross to Dartford, Euston to Watford Junction, Fenchurch Street to Ockendon, Liverpool Street to Broxbourne, Liverpool Street to Manor Park, St Pancras to St Albans City, St Pancras to Elstree and Borehamwood, Victoria to Oxted and Waterloo to Epsom.
Its findings revealed one in three mobile internet connections failed and one in seven voice calls on commuter trains didn't get through at all.
Vodafone, O2, Three and EE were all tested and although Three had the most stable coverage, EE's 4G service came out victorious.
Three out of the four networks rely on 2G connections while travelling at speed, meaning only voice calls could get through and data packets drop out when sending and receiving data during a journey. In fact, those carrying out the research spent 60 per cent of the time on 2G, resulting in negligible data speeds throughout the journey.
O2 was the worst offender for using 2G networks, followed by Vodafone and EE. Because Three doesn't have a 2G network to use, it only dropped to half-rate codecs to decode 8 per cent of voice calls.
Additionally, 23 per cent of 3G data connections and 37 per cent of 4G data connections fail while on the train routes and the worst places for this are St Pancras, Kentish Town and Radlett.
Paul Carter, chief executive of GWS, said: "It'd be great to see networks, rail operators and station-masters taking the lead on improving connectivity for commuters rather than having to be dragged into the 21st Century kicking and screaming."
