New Technology Pin Points Location of 911 Call from Cell Phone -

New Technology Pin Points Location of 911 Call from Cell Phone

In the early morning house on Saturday, a woman named Joan Walsh lost control of her car, which ran off a rural section of road in Jefferson County.  The car flipped and Joan found herself hanging upside down, held up only by her seat belt.

Joan was able to find her cell phone and dial 911, but in those first few frantic moments, Joan was not sure exactly where she was.

A dispatcher at the Jefferson County 911 call center was able to pinpoint Joan's location by a few hundred yards, thanks to new upgrades to the county's 911 system.  Just last month, the county finished upgrading to Phase II of an E-911 system that allows most emergency calls from cell phones to be traced. 

Voters in Jefferson County approved a half cent sales tax hike to pay for the service.  The total price tag is still unknown because the service is only a few weeks old, but Jefferson County Dispatch tells me that the annual service for one of their system upgrades costs $54,000.

Eventually the FCC will require all emergency answering services to upgrade.

The FCC has divided the E911 upgrade requirements into two parts.

This is how the FCC describes Phase I: Under Phase I, the FCC requires carriers, within six months of a valid request by a local Public Safety Answering Point (PSAP), to provide the PSAP with the telephone number of the originator of a wireless 9-1-1 call and the location of the cell site or base station transmitting the call.

Here's what the FCC says about Phase II:  Under Phase II, the FCC requires wireless carriers, within six months of a valid request by a PSAP, to begin providing information that is more precise to PSAPs, specifically, the latitude and longitude of the caller. This information must meet FCC accuracy standards, generally to within 50 to 300 meters, depending on the type of technology used. The deployment of E9-1-1 requires the development of new technologies and upgrades to local 9-1-1 PSAPs, as well as coordination among public safety agencies, wireless carriers, technology vendors, equipment manufacturers, and local wireline carriers.

Last November, St. Louis County voters agreed to set aside money for emergency communication upgrades:

Diana Zoga is a general assignment reporter at KMOV.  She can be reached at


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