AT&T, Sprint, T-Mobile and Verizon letting D.C. Metro handle cellular installation in train tunnels

AT&T (NYSE: T), Sprint (NYSE: S), T-Mobile (NYSE:TMUS) and Verizon (NYSE: VZ) customers should all soon have better coverage in the Washington D.C. subway system, and the carriers won't have to lift a finger.

The Washington Metropolitan Area Transit Authority is undertaking a massive effort to update and replace the radio communications in its underground rail system, a task that will involve installing 100 miles of cable on the tunnel walls. So since D.C. Metro is already going to be down there, it asked the four major wireless carriers if it could help improve wireless coverage in the tunnels while it's at it, and they accepted.

Dan Stessel, spokesperson for D.C. Metro, said the radio replacement project is happening due to a federal mandate requiring the transportation system to move its communications from the 400 MHz band to the 700 MHz band. Plans to improve cellular communications in the tunnels have been in the works for nearly 10 years but Stessel said the carriers' work to handle the installation themselves stalled out, particularly after Powerwave Technologies, a wireless manufacturer and contractor, declared bankruptcy in 2013.

But Stessel said there's a renewed urgency around improving cellular signals in the train tunnels following a 2015 incident when smoke filled a tunnel near L'Enfant Plaza, leaving one rider dead and 86 more sickened. Stessel said many riders had difficulty contacting emergency services with their mobile devices.

So to improve coverage in the tunnels, D.C. Metro workers will be installing 3-inch thick leaky coax cable along the tunnel walls at the height of the windows on the trains. Leaky coax cable functions as an antenna by allowing RF signals out through its conductor shield.

Stessel said that, though D.C. Metro is handling the installation, all four carriers are contributing cash and materials to the project, though he couldn't specify how much.

The entire project is expected to cost D.C. Metro about $120 million.

The leaky coax in the tunnels will work with the owned and operated wireless infrastructure all four carriers have already installed in the Metro stations.

In addition to the D.C. Metro tunnel project, all four top U.S. wireless operators are working with Transit Wireless to deploy distributed antenna systems (DAS) across 277 underground subway stations for the New York City Transit Authority (NYCTA).

For more:
- see this Metro press release

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