The Federal Communications Commission is reviewing whether or when the police and other government officials can intentionally interrupt cellphone and Internet service to protect public safety.

Late Thursday, the commission requested public comment on the issue, which came to widespread attention last August, when Bay Area Rapid Transit in San Francisco shut off cellphone service for three hours in some stations to hinder planned protests there.

The transit system interrupted service without notice to the F.C.C. or the California Public Utilities Commission. The interruption was in anticipation of protests in BART stations in response to the fatal shooting of a man in July by a BART police officer.

Julius Genachowski, the F.C.C. chairman, said in a statement that such a shutdown “raises serious legal and policy issues, and must meet a very high bar.”

“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.

Ms. Salaver said the transit system welcomed the F.C.C.’s look at what rules should govern privately owned cellphone transmission equipment. The BART system owns the wireless transmitters and receivers that allow for cellphone reception within its network. A coalition of public interest groups petitioned the F.C.C. in August to declare that BART violated federal law, in part because shutting down communications networks endangered, rather than enhanced, public safety.

“The same wireless network that police see as a tool for rioters to coordinate is the same wireless network used by peaceful protesters to exercise our fundamental freedoms,” Harold Feld, legal director for Public Knowledge, one of the groups that petitioned the F.C.C., said Friday. “In any event, the network will be necessary for people in the area to call for help or to let family members know they are not harmed.”

While noting that rules exist for service interruption during emergencies, the F.C.C. expressed concern that “there has been insufficient discussion, analysis and consideration” of the questions raised by the intentional interruptions.

About 70 percent of all 911 calls now originate from wireless phones, the F.C.C. said. It asked for comment from the public and from wireless phone companies on whether the cellphone companies could carry out a general service interruption while ensuring that the public could still make wireless 911 calls.

Comments will be accepted at the F.C.C. through April 30. The public will then have another month to reply to comments filed during the initial period.