A cell phone can be a lifesaver. That is, when a 911 operator can pinpoint a mobile caller's location. But would such tracking technology also occasionally mean an unacceptable loss of privacy for cell phone users?
For years, both the telecommunications industry and public safety answering points — or PSAPs, the call centers that answer local 911 calls — have struggled to add so-called Enhanced 911 technology.
Industry watchers say the technology needed to locate mobile cell phone calls isn't difficult to implement. And recent tragedies, such as the disappearance of four teens boating on the Long Island Sound after a New York City PSAP failed to pinpoint their mobile phone's location, are spurring a public cry for cell-phone tracking technology.
Yet some are concerned that the demand for more call tracking technology might also harm privacy.
"There certainly need to be better emergency procedures [for cell-phone calls]," says David Sobel, general counsel for the Electronic Privacy Information Center in Washington, D.C. "But once the technology exists, there has to be some way for users to control how the info can be used."
Tracing Cells for Now
A cell-phone call can be tracked by one of several different means.
One relatively easy method would require a simple modification to existing software and hardware used to handle and route calls within a cellular phone service's network. Since each cell phone is basically a radio transmitter that broadcasts (and receives) signals from a system of local cell-phone antenna towers, a wireless network always "knows" where a particular phone is generally located within an area.
Travis Larson, a spokesman with the Cellular Telecommunications Industry Association, says such basic E911 service can only give a rough idea of where a caller may be located, since each local cell-phone network uses various antenna towers in a given area.
"In a rural area, you might be able to narrow a cell call down to a mile [from the tower],' says Larson. "In the city, you might be able to get it down to within a few blocks."
Such basic location schemes — described as "Phase One" E911 services by the FCC — has been pursued most aggressively by the telecom industry and the local emergency response agencies, according to the National Emergency Number Association, or NENA, a non-profit advocacy group.
"Of the [more than] 5,200 PSAPs, about two-thirds are in Phase One deployment," says Jim Goerke, the wireless implementation director for NENA.
Networks That Know Where You Are
Now, however, following an FCC requirement mandated in October 2001, cellular service providers must deploy a more accurate E911 system, so-called Phase Two.
Under the next stage of wireless E911, every cellular phone service provider would be required to share with PSAPs a user's actual location data.
The technology used by wireless service providers to implement phase two E911 may vary, but CTIA's Larson says to produce that type of accuracy, many wireless service providers will be turning to global positioning satellite, or GPS technology.
GPS chips inside a cell phone would be able to determine its location from signals from space-based satellites. That data is then sent along with the cell phone's number, whenever a subscriber calls 911.
By the end of 2005, wireless E911 systems are expected, at a minimum, to help operators pinpoint a cell-phone caller's location to within 100 meters 95 percent of the time.