November 24, 2015 — The Metropolitan Transportation Authority and Transit Wireless have launched the Phase 4 expansion of wireless services to 21 underground subway stations in the Bronx and 16 more stations in Manhattan. The network build-out so far has brought underground connectivity to 70 million MTA riders monthly in Manhattan, Queens and now the Bronx.
A celebration was held November 12 at the Yankee Stadium Station with personnel from the Metropolitan Transportation Authority, Transit Wireless, AT&T, Sprint, T-Mobile and Verizon Wireless.
It all began back in April 2013, when Phase 1 connected 30 midtown Manhattan underground stations; Phase 2 was completed in October 2014, connecting 76 stations; and Phase 3 was completed in March 2015, connecting stations in Lower Manhattan. As of today, 146 underground stations are connected to the Transit Wireless network.
Transit Wireless provides coverage to 95 percent of the subway’s public access areas, including stairwells, mezzanines and other ingress and egress is designed to provide a -85 dBm signal. The RF signal is actually higher because in a subway, which generally has zero macro penetration, the noise floor is nearly zero.
The wireless system, not only provides cellular DAS communications, but also a secure, private public safety network and public Wi-Fi services.
“In the stations, we have actually built a parallel network, with coax cable going from SOLiD’s remote nodes to DAS antennas, and we also have 12-strand fiber going to every single access point, which provide Wi-Fi access and 4.9 GHz public safety communications,” Nathan Cornish, director of RF engineering at Transit Wireless, said in a phone interview.
The biggest challenge of the subway system buildout for Transit Wireless is providing coverage in the transition areas where the users are moving from the macrocell signal to the DAS signal, according to Cornish. “We spend a great deal of time with the carriers ensuring that the coverage is seamless,” he said. SOLiD provided the Alliance Multi-carrier DAS remote units with 5 watts of power, which help to make the coverage seamless.
The harsh, unforgiving environment of the subway, which includes brake dust and nightly power washing, has become a proving ground for the development of wireless equipment that integrator have benefiting from elsewhere.
To deal with the subway environment, SOLiD uses NEMA-rated enclosures to protect the remote units deployed in the ceiling above the platforms. The remote units also use a passive heat exchange cooling system has so that there are no fans and moving parts that can fail.
“There a lot of the vendors and suppliers to this subway project that have heard the call to innovate in order to bring appropriate solutions to the difficult problems posed by this project,” Michael Collado, vice president, marketing, SOLiD, said. “The 5-watt Alliance multi-carrier DAS product that is being deployed by Transit Wireless was born out of the needs and requirements of the environment of the New York subway.”
Transit Wireless has initiated design and construction work on the fifth phase of the seven-phase project to wire all 279 underground MTA stations. When completed, Phase 5 will bring another 37 stations online by mid-2016, including the first stations in Brooklyn. Phases 6 and 7 of the Transit Wireless network build-out will connect the 90 remaining Brooklyn and Manhattan underground stations in 2017, about one year ahead of schedule.