For cell phone users, having a service signal is crucial, even when the user is traveling in a subway system. Realizing this dilemma, two transit authorities are looking at ways to resolve the issue. The Chicago Transit Authority (CTA) recently awarded a $11.2 million contract to Aldridge Electric Inc. in Libertyville, Ill. , to create and oversee its wireless telecommunications system. Work on the project is expected to begin this spring and be completed in about 18 months. Since installation will occur during off-peak hours, no major service interruptions are expected. “Wireless telephone service is an integral part of life these days,” said Valerie B. Jarrett, Chicago Transit Board chair. “Customers will be able to stay connected to their businesses and families, and we want to provide them the means to do so.” In addition to serving customers, the wireless system will improve internal communication at the CTA, Jarrett said. In San Francisco, the Bay Area Rapid Transit (BART) has been kicking around the idea of installing a wireless telecommunications system into its subway tunnels and stations for a couple of years. “But with the economy in the tank, corporations are holding back on investments,” said BART spokesman Ron Rodriguez. Andrew Corp., a telecommunications firm, earlier proposed a plan to wire all the tunnels and stations. The idea was for Andrew to pay BART a franchise fee and then collect a leasing fee from cell phone providers who wished to use the system. However, as the economy began to falter, the firm put its plans on hold. BART would prefer that a single company handle the overall process. “I think the best bet would be one company sublet its usage to the others,” Rodriguez said.