Washington Metropolitan Area Transit Authority (Metro) signed an agreement with Verizon Wireless, Sprint Nextel, AT&T and T-Mobile to build a new wireless infrastructure in the underground rail system during the next four years.

Riders will be able to call home from any cell phone, access the Internet from any Web-enabled cell phone and, eventually, have Wi-Fi access in the rail system.

The companies will design, build, operate, maintain and own the wireless network. The firms will also build a second wireless network, which Metro will own, operate and maintain for Metro’s own operational and public safety communications. Twenty of the busiest underground rail stations will have expanded cell phone service by the end of this year, and the entire rail system will be equipped by 2012.

Riders can now receive cell phone service from multiple providers at above ground stations, but the current underground wireless network only supports Verizon customers and Sprint phones that roam onto the Verizon network.

The wireless contract will generate a minimum of nearly $25 million during the initial 15-year term and an additional $27 million during the five, two-year renewal terms. Other FCC licensed and unlicensed carriers can gain access to the networks either through entering into agreements with Metro or the group of carriers, all of which will produce additional revenue for the transit agency.