The rules, announced Friday by the Federal Communications Commission, are intended to help law enforcement authorities keep pace with advances in phone technology. Privacy groups complained that the government was effectively turning cellular phones into tracking devices.
Another rule would allow investigators to listen in on phone conversations of all parties to a conference call, even if some are put on hold and are no longer talking to the target of the legal wiretap. Authorities with a court order also could determine when someone is using call-forwarding, three-way calling or other features.
"Our actions today will help ensure that law enforcement has the most up-to-date technology to fight crime," FCC Chairman Bill Kennard said.
The rules help implement a 1994 law that requires companies to make digital wiretapping technology available to law enforcement agencies. The commission stepped in after the Justice Department, FBI and the telecommunications industry failed to agree on a plan after years of negotiations. The Justice Department and FBI got much of what they sought.
The companies have until March 2000 to set equipment standards that integrate the added requirements and until Sept. 30, 2001, to implement them.
The Justice Department said the FCC's order addressed its major concerns and would aid officers in fighting terrorism, organized crime and illegal drug activity.
"The continuing technological changes in the nation's telecommunications systems present increasing challenges to law enforcement," Attorney General Janet Reno said. "This ruling will enable law enforcement to keep pace with these changes and ensure we will be able to maintain our capability to conduct court-authorized electronic surveillance."
Privacy groups said the FCC overstepped the 1994 law.
"We are deeply disappointed that on all the issues that mattered, the commission ruled against privacy and in favor of expanded FBI surveillance," said Jim Dempsey, counsel at the Washington-based Center for Democracy and Technology.
Industry groups said communications companies will have a hard time meeting the deadlines.
"It's a real time crunch and resource drain," said Grant Seiffert, vice president for government relations at the Telecommunications Industry Association, which represents major equipment manufacturers.
The requirements also will be costly for the nation's local phone companies, according to the United States Telephone Association.
Tom Wheeler, head of the Cellular Telecommunications Industry Association, said he hoped law enforcement authorities would "provide carriers with the flexibility necessary to implement these capabilities in a way that makes sense."