By Gayle White
The Atlanta Journal-Constitution
ATLANTA — When it comes to calling 911, cellular telephones are a mixed blessing, emergency response officials say.
A cellular caller can summon help from a car or a campsite miles from a land line; but technology doesn’t pinpoint the location of a cellphone as precisely as that of a stationary telephone.
In situations where callers can’t speak or can’t give an exact location, emergency responders are less likely to know where to go.
“Cellphones are a two-edged sword,” said James Bothwell, executive director of Grady Health System’s emergency medical service. “Without a doubt, they have been extremely helpful in summoning people to emergencies where there are no other phones available. The problem is when we receive a cellphone call and the person doesn’t know where they are.”
Use of a cellphone may have contributed to the delayed response to a call by Darlene Dukes, a mother of two who died from a blood clot in her lungs after waiting more than an hour for an ambulance Aug. 2.
Dukes, a Verizon employee, called for help from a cellphone and told an operator at the Fulton County 911 center that she was on Wales Drive, which is in Johns Creek in north Fulton. But the operator misunderstood the woman’s location as Wells Street in southwest Atlanta.
After an ambulance was sent to the Atlanta address, a dispatcher realized the cell call had originated in north Fulton. Even then, there was no precise address.
“Obviously, wireless phones can be an unbelievable safety tool,” said Chuck Hamby, regional public relations manager for Verizon Wireless. “But you do need to know what they can do and can’t do.”
When a 911 call from a land line goes to a call center in an area with enhanced 911 service — such as jurisdictions in metro Atlanta — a specific address pops up on a computer screen.
But the electronic information an operator receives from a cellphone is determined by the age and model of the phone, the carrier, and the technology in the call center, said Joe Farren, a spokesman for CTIA — The Wireless Association, a trade group.
The Federal Communications Commission requires that cellphone carriers provide a means to determine the origin of an emergency cellphone call, but the location is far from exact.
Most large cellular companies — Verizon, Sprint Nextel and Alltel — fulfill the requirement by implanting a global positioning device inside the phones they sell. Since the end of 2005, all new cellphones from those companies have had GPS chips. Older phones may not have them.
AT&T and T-Mobile use a different technology. Those companies locate a cellphone by “triangulating,” or citing its position among the three closest cellular towers.
Both methods are “as good as today’s technology allows,” Farren said, “but the system is not precise.” And not all call centers have the receiving technology necessary to accept the electronic information from a cellphone.
In Georgia, more than 8 in 10 cellphone customers are in areas that do have the advanced technology, according to the National Emergency Number Association, a group that promotes universal 911 service in North America.
But high-rise buildings in urban areas can make global positioning difficult, NENA spokesman Patrick Halley said. On the other hand, triangulating is difficult in more rural areas where cell towers are widespread.
The system, he said, “is not perfect by any means.”
Elaine Sexton, 911 program administrator for the Georgia Emergency Management Agency, said people should use a cellphone for a 911 call if it’s the only phone available; but anyone with a choice should make a 911 call from a land line.
Staff writer Marcus K. Garner contributed to this article.