T-Mobile customers will soon have reception underground on the Red and Blue Lines in Chicago for at least the next 10 years.

T-Mobile will become the fifth wireless service provider to sign a contract with the Chicago Transit Board, the latest since AT&T, which signed the contract in June.

The contract will give T-Mobile customers cellular service in underground subways. The payments from the 10-year contracts are expected to generate at least $15 million in new revenue for the Chicago Transit Authority.

During the next several months, testing of T-Mobile’s base equipment—which includes amplifiers, transmitters and receivers ­­ will take place in the subways to ensure a strong signal for their customers. Currently, the only wireless providers that have service underground are Cricket Communications, Verizon Wireless and U.S. Cellular.

Wanda Taylor, manager of Media Relations for the CTA, said all underground wireless service providers will be using the improved $11.2 million fiber-optic infrastructure system, which the CTA installed in 2005. The fiber-optic infrastructure allows the use of wireless devices, such as cell phones and wireless Internet modems throughout the 11.4-mile subway system.

“The improved telecommunications system also laid the groundwork for the agency to generate additional revenue by leasing its wireless infrastructure for commercial service,” Taylor said.

T-Mobile and AT&T customers will still have to wait until the end of the year to receive underground service. The companies are still installing and testing equipment to ensure customer satisfaction.

Taylor said there won’t be any train delays or detours because of the wireless testing being done by T-Mobile and AT&T.

Some customers who still don’t have underground­­ cell phone service have thought about switching companies in order to receive  service.

Charlene Williames, a banker, says she is excited that AT&T, which is her service provider,  will have underground service.

“If they’re getting ready to [have service] I would really appreciate it,” Williames said.

As the CTA continues to face budget challenges, it is important to pursue initiatives like this to provide benefits for customers while producing revenue for the CTA, said CTA president Richard Rodriguez in a press release.

The CTA isn’t funding testing and setup of the new wireless services, so no fare increases are expected.

The two companies hope to repeat U.S. Cellular’s success and attract more customers in Chicago once underground service is instituted later this year.

“A lot of our sales [rely] on our service, how good it works, where it works and where it doesn’t,” said Stephanie Giraldo, sales representative for U.S. Cellular.

Giraldo said she uses U.S. Cellular’s underground service as a sales strategy when trying to sign a customer to the company.

Underground isn’t the only place where downtown commuters should worry about getting service, Giraldo said. Getting service in buildings and establishments in the downtown area can be a hassle because of the building infrastructure.

“If you’re downtown, a lot of places – because of the [size] of the buildings – service gets shut off … having underground towers helps people get service,” Giraldo said.

During the next few months, T-Mobile and AT&T crews will be working to ensure quality service andd a strong signal for their customers.