Asked about the loss of emergency dialing service, Franklin said BART had police officers and other workers stationed on trains and platforms during the mobile phone outage.

"Every few feet, there was either a police officer or someone with a radio," he said. "If you had an emergency, you turned to your right or your left and said, 'I have an emergency.'"

BART's board is considering a new policy that would shut down mobile phone service only in extreme circumstances, Franklin added. The protests may not qualify as an extreme situation in the future, but BART police will need some flexibility to deal with issues on a case-by-case basis, he said.

The FCC is to cut off mobile service, according to an agency spokesman.

The Aug. 11 protest didn't happen. It was planned in response to the July 3 fatal shooting of a knife-wielding BART passenger by BART police.