T-Mobile Expands MBTA Wireless Service to Blue and Green Lines Throughout Boston
Partners with MBTA and InSite Wireless to offer new wireless service to T-Mobile customers on the Blue Line between Maverick and Bowdoin and on the Green Line from North Station to Kenmore.
How service is provided: The distributed antenna system (DAS) acts like a radio tower, with some special adaptations to transmit and receive signals underground. Instead of broadcasting radio signals to cover a broad geographic area from antennas mounted on a tower or building rooftop, the system converts radio signals to light using lasers and carries the signals to remote locations throughout the tunnels and stations on fiber-optic cable. Equipment at the remote locations converts the light signal back to radio, amplifies it and transmits it through an antenna system. The antenna system includes both antennas and radiating cable. As an analogy, the antennas “spray” radio signal like the stream of water from a nozzle while radiating cable and distributes signal along the length of the tunnels. The system includes 71 remote amplifier locations, 354 antennas and 41,585 feet of radiating cable. Subscribers’ phones, smartphones, PDAs and wireless modems communicate with the underground antennas to complete phone calls and data sessions. InSite provides the backbone infrastructure for the DAS; the carriers connect their equipment to the system head-end and are responsible for the signal provided to the DAS.
Where coverage is provided: The InSite DAS provides continuous service in stations and in trains as they pass through underground tunnels. Callers can place a call above ground, carry it underground, and continue the call until they finish underground or return back above ground and keep talking all the while. In addition to voice calls, the system supports texting and data services for email and Web browsing, as well as smartphone applications.
How the network is monitored and improved: InSite’s DAS Network Operations Center monitors system operations, provides remote diagnostics and reports alarms. The system, as built, will support all current wireless technologies and may be easily upgraded to add future services as they are developed.