A call can now be held continuously in all the underground sections of the Orange Line from Massachusetts Avenue through Back Bay, New England Medical, Chinatown, Downtown Crossing, State Street, Haymarket, North Station, and under the Charles River to Community College. T-Mobile and AT&T will provide service at these locations.
In December 2007, the MBTA became one of the first subway systems in the country to provide underground wireless telephone service with wireless telephone service at four key downtown locations and in the connecting tunnels: Downtown Crossing, Park Street, Government Center and State Street. In May, a similar extension of service will encompass the Red Line tunnels and underground stations. Calls will be able to be carried continuously from Charles / MGH through Park Street, Downtown Crossing, South Station, Broadway, and Andrews to JFK / UMass. The underground sections of the Blue and Green Lines are currently in design.