By year’s end, all underground portions of the MBTA subway system are expected to be wired to allow mobile carriers to provide cell phone reception, the company installing the cellular infrastructure says.
That will make Boston’s subway among the first in the country where some riders can text, call, check e-mail, and browse the web no matter where they are in the below ground transit system, according to Joe Mullin, vice president of engineering and operations at InSite Wireless, LLC.
Individual cell phone carriers must each work out agreements with InSite Wireless, which charges them to connect and gives a cut of that revenue to the MBTA.
Both AT&T and T-Mobile are expected to broadcast voice and data reception throughout subterranean areas of the subway system shortly after InSite Wireless finishes its work, officials said.
But customers of other carriers might have to wait longer: no other major mobile carriers have immediate plans to introduce or expand their underground coverage.
The T expects the deal will net the agency about $5.3 million altogether over the course of a 15-year contract with InSite Wireless. That figure will rise as the areas where cell service is offered expand and as more carriers sign on, spokesman Joe Pesaturo said.
In March, T-Mobile added service along the entire Blue Line and on the Green Line, except at Prudential and Symphony stations, according to spokeswoman Patty Raz.
AT&T expects to add service to the Blue Line and that same portion of the Green Line “later this summer,” spokeswoman Kate MacKinnon said.
Both companies have offered service on the entire Orange Line and some of the Red Line since 2010.
Subway cell reception launched in 2007 at four downtown stations – Government Center, Park Street, Downtown Crossing and State Street – and the connecting tunnels between them. Verizon offers service there. It is the only below-ground section where a carrier other than AT&T and T-Mobile offers service.
Verizon spokesman Michael Murphy said the company “remain[s] in discussions” about the potential for expanding service within the subway system.
MetroPCS spokesman Drew Crowell said the company is “interested and looking into,” joining the below-ground mobile network.
Sprint spokesman Mark Elliott said the company is "evaluating our options" for providing underground cell service along the T. None of the spokesman commented further.
InSite Wireless began its efforts in 2005 when the company signed its contract with the MBTA. Mullin said the company expects two five-year renewals will be used, extending the partnership through at least 2030.
The company is completing the final part of a four-phase installation process.
By the end of the year, carriers will be able to broadcast their service from untapped areas of the Red Line, between Kendall and Alewife stations and between Shawmut and Ashmont stations, as well as inside Prudential and Symphony stations on the Green Line’s E branch, according to Mullin.
Those projects are the last of InSite Wireless’ installation plans that will provide cell carriers the chance to offer continuous mobile reception through all of the MBTA’s 35 underground stations and its 19 miles of tunnels, he said, declining to disclose the undertaking’s cost.
The system converts radio signals to light using lasers. Fiber-optic cables carry the light signals to remote locations throughout the subway. Equipment at the remote locations converts the light back to radio, amplifies it and transmits it through an antenna system to mobile devices within reach.
In all, Mullin said 98 remote amplifiers, 422 antennas, and 71,455 feet of radiating cable will be burrowed within the T’s lairs to complete the distributed antenna system – a noteworthy feat given the constraints that come with working inside the nation’s oldest subway.
“The challenge in Boston is that there’s only two tracks,” which, unlike some other subway systems in the country, prevents any work from being done while trains are in operation, he said in an interview last fall. “You only get to go on the tracks between 1 and 5 a.m.”
Getting the equipment and workers into the tunnels and leaving enough time to clear the area before the morning commute often only allows crews to get about two to three hours of work in each night, he added.
Shortly after T-Mobile debuted underground service on the Blue and Green lines this spring, the company says it compared the use of its MBTA cell network recorded during a one-week span before the expansion to a one-week span afterward.
The 205,000 text messages sent from the subway-riding T-Mobile users marked an 83 percent spike. The 330 gigabytes of data was a 37 percent jump. More than 160,000 calls were placed – a 22 percent increase, according to the company, which subscribes more than 1 million customers in Boston.
"Our customers want to stay connected wherever they go — and now their conversations, texts and Web use doesn't have to end when they travel underground in Boston,” said a statement from John Diefenbach, the company’s regional vice president and general manager.
A company spokeswoman said that while 4G access is not yet available below ground, the system, as built, can be easily upgraded.
And, the underground network has been accessed beyond just being a way to keep casual mobile exchanges going, play games and stream music. In the past year, more than 8,800 calls from T-Mobile’s subway network were made to 911.