“Our democracy, our society and our safety all require communications networks that are available and open,” he said. “The F.C.C., as the agency with oversight of our communications networks, is committed to preserving their availability and openness, and to harnessing communications technologies to protect the public.”

Among the issues on which the F.C.C. is seeking comment is whether it even has authority over the issue. The public notice asks for comment on whether the F.C.C. itself has legal authority over shutdowns of wireless service and whether it can pre-empt local, state or federal laws that prohibit or constrain the ability of anyone to interrupt service.

In December, after considerable outcry from civil liberties groups and some members of the public, the BART board adopted a policy saying that a temporary interruption of cellphone service would be allowed only when the agency “determines that there is strong evidence of imminent unlawful activity that threatens the safety of district passengers, employees and other members of the public.”

As examples, the policy cited evidence of any planned use of cellphones as triggers to set off explosives or as networks to facilitate violent criminal activity or to endanger passengers.

Under the new policy, BART would not have turned off the wireless phone system under circumstances similar to those in August, said Luna Salaver, a spokeswoman for BART. Instead, she said, police officers would have arrested individuals who were breaking the law.