The wireless carrier had been droppingsince October that it was unhappy with its original choice of technology and was looking to find a new one.
The switch exposes the company to a possible fine by the Federal Communications Commission. Cingular plans to ask the FCC for a new deadline to comply with Enhanced 911, or E911, requirements, a company representative said Tuesday. FCC regulators have alreadyCingular and other carriers for missing earlier deadlines.
The nation's wireless carriers have until 2004 to create a service that lets emergency call centers locate people who dial 911. Emergency call centers credit their ability to locate a landline phone with saving the lives of those unaware of where they are or too injured or panicked to provide any details. With more than half of all 911 calls now coming from cell phones, emergency call centers say they need the E911 service more than ever.
Carriers AT&T Wireless, Cingular and T-Mobile had originally chosen to use a technique called(EOTD), which uses up to four cellular base stations to pinpoint a cell phone's location by measuring the arrival times of the call at various cellular antennas.
EOTD works well in cities, where cell phone antennas are plentiful, but in rural areas cellular antennas are sometimes miles apart. Instead of four base stations, often there are just two to help determine a location, which makes the measurement less accurate, said Chris Wade, chief executive of EOTD inventor Cambridge Positioning Systems.
In October, Cingular said EOTD equipment was having trouble meeting the level of accuracy that the FCC wants. The poor performance is creating "continued uncertainties regarding the ability of EOTD to satisfy the commission" deadlines, attorneys for Cingular said in the filing.
The replacement technology, called Uplink Time Difference of Arrival (U-TDOA), determines a phone's position by measuring the time a call reaches "location measuring units" inside a cell phone network base station.
Carriers installing the technology, created by TruePosition, need only to add software into their networks. EOTD, on the other hand, requires software in a network plus specially made handsets.
Cingular has already tested the U-TDOA system in Wilmington, Del., and the technology exceeded, in some cases, the FCC's accuracy requirements, Cingular said in a recent FCC filing.
A TruePosition representative would not comment on whether the company has been approached by AT&T Wireless and T-Mobile for a possible switch as well.