Franklin County to test system to pinpoint calls from cell phone

May 14, 2006|by DON AINES


This week, Franklin County will begin testing a wireless 911 system capable of narrowing down the area from which an emergency cell phone call is originating, but by the end of the year, a system will be in place that can pinpoint the location of a call from GPS-equipped cell phones.

Wireless 911 Phase I will "narrow down the address of the tower the customer is hitting," said Bryan Stevenson, the county's emergency communications coordinator. "It will provide the sector they are utilizing and provide the 'X' and 'Y' coordinates of the tower site."

"The dry run is next week, so we'll be operational soon thereafter," said Jerry Flasher, the county's director of emergency services.


Five cellular phone companies provide service in the county at 68 tower sites, Stevenson said. The number of actual tower sites is fewer than that because some companies share space on the same towers, he said.

To make Phase I work, the cell phone companies had to supply the county with tower site data, including its address, and longitude and latitude. Towers have three sectors, each covering a 120-degree arc, and each sector is assigned a telephone number, Stevenson said.

Under the system now in place, a 911 call is picked up by a cell tower, and the signal is converted to a seven-digit telephone number and routed to one of six phone lines dedicated to 911 service in the emergency communications center.

"With some phones, depending on the age, we don't even get caller ID," Stevenson said.

The dispatcher might see the phone number and identification of the caller, but no information about the location, he said.

The technology for Phase I is somewhat similar to that by which a small airplane was found after it crashed last month near St. Thomas, Pa. Calls to the missing pilot were routed to a cell tower there, narrowing the search area, but that required backtracking the information through the cell phone company, said Gary Himes, the county's hazardous materials coordinator.

Phase I will narrow the search area to a matter of square miles, but Phase 2 will enable a GPS-equipped cell phone call to be pinpointed "within meters," said Mark Grimes, a 911 field engineer for the county. If the caller is moving, the system will update every 30 seconds so the position is tracked, he said.

"The cell companies ... as contracts expire are requiring upgrades," meaning all cell phones eventually should be equipped with GPS, Flasher said.

A person making a call to 911 from a GPS cell phone will have their longitude and latitude information relayed to the communications center, Grimes said.

Pinpointing the location of the call requires the installation of appropriate computer hardware and software, including Geographic Information Services (GIS) software.

Most of the money for the system is paid for by cell phone users in Pennsylvania through a surcharge for wireless 911 service, Flasher said. Some funding also is coming through the U.S. Department of Homeland Security, he said.

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