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Wireless 911

Cellular phones have had a major impact on society and the world in general. Over 50% of the population of Tennessee has a cell phone. What has been a great technological improvement for most, has been a nightmare for 911. With landline phones the name and address of the caller are displayed to the dispatcher. With cell phones unless the caller could tell the dispatcher where they are located it was impossible to find them.

The Federal Communications Commission realized that some form of technology was needed to locate cell phones in times of emergencies. The commission came up with Wireless E-911 requirements that established requirements on the wireless carriers to implement technology to locate the cell phones. The requirements were divided into Phase I and II.

Phase I
Provides the cell phone number and the cellular tower that the call is coming from. This allows the dispatchers to at least call the person back if they need more information or have problems locating the caller.

Phase II
Provides the latitude and longitude of the cell phone. This amazing technology allows the caller to be pinpointed to within 50 to300 feet in normal conditions. This allows emergency units to find callers even though they cannot speak or give directions to their location. Click here to see screen shots of our GIS mapping system locating calls.

Types of Location Technology
There are two ways of locating a cell phone’s Phase II location. One uses what is called “Network Solution” and the other is called “Handset Solution”. The network solution uses triangulation of the cell towers to locate the cell phone. With this solution, all cell phones on the network are Phase II. The handset solution requires the cell phone to have a GPS chip. Most new cell phones have the chips already installed. Most older phones do not. The wireless carrier has the choice of which solution they use. Consumers buying a new cell phone should check with the carrier to make sure they are Phase II compatible

All wireless carriers are required to have Phase II implemented by December 31, 2005. Thanks to the Tennessee State 911 Board and it’s aggressive approach to this new technology, Tennessee is one of the nation’s leaders when it comes to Phase II deployment.

Here’s a list of wireless carriers in Henry County and status of deployment:

Wireless Carriers in Henry Co. Phase I Phase II
AT&T Yes Yes
Verizon Yes Yes
Wireless Carriers Not Available in Henry Co. Phase I Phase II
Nextel Yes Yes
Sprint Yes Yes
T-Mobile Yes Yes