The San Francisco Bay Area Rapid Transit (BART) District has found a unique way to create a profitable business, pay for part of the effort to reconfigure its 800 MHz private wireless system, and bring five competing commercial mobile services underground — an arduous and expensive proposition — at the same time.

Chuck Rae, a 40-year veteran and manager of telecommunications revenue with BART, is the man primarily responsible for this initiative. Nearly 20 years ago, BART conceived a program to develop a right-of-way business for the dark fiber that it uses to power its proprietary radio system. It marketed the fiber to commercial entities such as cable and telecom operators.

That business has been a nice revenue-generator for BART. Years later, as mobile services enjoyed massive adoption, demand for wireless services began to emerge underground. In addition, the capabilities, namely distributed antenna systems (DAS), were there to enable it. So Rae and his team embarked on another initiative to bring competing commercial services underground and make money in the process.

"We were developing the above-ground revenue area, as far as licensing areas above ground for different companies to put their sites," Rae said. "That was the emphasis of the wireless program. Then as technology increased, operators were able to transmit below ground. We thought there was no reason why we couldn't work out some type of agreement to have wireless service underground."

It took nearly six years to hammer out agreements among all of the major commercial operators —AT&T, Verizon, T-Mobile and Sprint Nextel — but the initiative was completed in 2008. The agreements cover cost sharing, licensing fee payments to BART, maintenance and warranties, and the designation of one lead operator to oversee all of the cost-sharing agreements. Sprint Nextel is the lead carrier.

BART hired Andrew Corp. to install a neutral-host DAS system that runs on BART's radio access network. Early on, BART took the attitude that it wasn't going to allow anyone to use its system. But the rebanding effort associated with Sprint Nextel changed the agency's attitude. While Sprint Nextel is paying the rebanding bill, it wouldn't pay for a new fiber-optic cable that BART believed it needed to support the rebanding effort, one that came with a $70 million price tag. Andrew helped facilitate a discussion between Rae and the public-safety communications side of BART to strike an agreement to use the dark fiber Rae's organization had been leasing to commercial operators.

"We needed a fiber cable, so we decided to share this fiber cable between the BART system and the commercial system and let commercial carriers [connect to the cable and pay a fee] back to BART," Rae said. Operators also have access to the radiating cable that is running under the private radio system.

Rae calls the move a "win-win" for BART and the commercial operators. For BART, the deal allowed the agency to avoid spending more money on fiber. Meanwhile, the operators would have never been willing to invest the infrastructure necessary to bring their own commercial services underground. "There would have never been a payoff date for them," he said.

The profits that BART makes from its telecom initiatives go to a host of initiatives. First, the money was used to pay off the debt incurred from building its proprietary radio system, which is now Project 25–compliant and interoperates with the P25 radios carried by first responders in San Francisco.