Chicago plans to upgrade wireless service to 4G in its subways and other underground transit facilities.
Much of Chicago's commuter train network is elevated above street level, but more than 11 miles of the system is underground.
The existing wireless service in those tunnels dates back to 2005, before the widespread use of smartphones and tablets, and cannot support modern wireless data needs.
The Chicago Transit Authority announced Thursday it has chosen Aldridge Electric Inc. for the $27 million project. Work could start in November. It's expected to take 12 months.
The upgrade on the Red and Blue Lines will give passengers faster, more reliable voice and high-speed data service on all major carriers.
Mayor Rahm Emanuel says it will boost ridership and the city's economic competitiveness.