Phase II Wireless Information

Background Information:

(Taken from Spread Spectrum Scene - http://www.sss-mag.com/e911.html )

"In 1996, the FCC issued a Report and Order requiring all wireless carriers and cell phone manufacturers to provide the capability for automatically identifying to emergency dispatchers the location from which a wireless call is being made. Timing for implementing the E911 requirements is divided into two phases. Phase I requires wireless carriers to deliver to the emergency dispatcher the telephone number of a wireless handset originating a 911 call, as well as the location of the cell site or base station receiving the 911 call, which provides a rough indication of the caller's location. This phase was implemented by the end of 1998."

"Phase II requires carriers to deliver more specific latitude and longitude location information, known as Automatic Location Identification (ALI), to the dispatcher."

Technical Information:

A callers location can be determined by 2 different methods:

• GPS Method - http://www.al911.org/wireless/gps_location.htm

• Triangulation Method - http://www.al911.org/wireless/triangulation_location.htm

What this means for Pittsylvania County:

Here in Pittsylvania County, we are working closely with an experienced consultant assigned to us by the State to assist us in implementation of Phase II Wireless.  Currently, Nextel Partners, Alltel & Suncom have implemented E911 Phase II Wireless in Pittsylvania County.  Other wireless carriers are scheduled to come on board shortly.

When someone dials 911 within our county on a GPS enabled telephone or cellular network that is Phase II enabled, our CAD system "talks" to our E911 phone system, taking latitude and longitude coordinates and plotting the callers location on the dispatchers map, as seen below.  

Links:

VITA Public Safety Communications Division - http://www.911.virginia.gov/wireless.htm