Enhanced 9-1-1 service in Littleton

When someone dials 9-1-1 from within the City of Littleton or the Littleton Fire District using a traditional phone ("land line"), the call is routed to the City of Littleton Communications Division, which then distributes the call to the proper emergency services. The caller's phone number and the exact location of the call is diaplayed on the dispatcher's screen. Prior to 1998, 9-1-1 calls from a cell phone did not have that capability, so the steps were taken to help correct the issue.

Enhanced 9-1-1 (E-911) service was rolled out in two phases. Littleton Police Communications and Littleton Fire Communications are capable of receiving both Phase 1 and Phase 2 cellular 9-1-1 calls, depending on the capabilities of the cellular phone carrier.

• Phase 1 calls display the tower location and the cell phone number. A wireless 9-1-1 Phase I call received into the center will be displayed on the dispatcher's telephone screen, along with the wireless phone call-back number, cell provider, and the cell tower address information. The location of the cell tower will simultaneously show on a mapping computer. This does not give the dispatcher a specific location of the caller.
   
• Phase 2 calls display the cell phone number and the latitude and longitude of the caller within 300 meters, depending on the cell phone carrier. Verizon, Nextel, Sprint PCS, and US Cellular all use a GPS chip, which is accurate to within 25 meters. T-Mobile uses a triangulation chip, which is accurate to within 300 meters. A wireless 9-1-1 Phase II call received into the center will also be displayed on the dispatcher's telephone screen as latitude/ longitude coordinates, along with the wireless phone call-back number and cell provider. The FCC requires 150-meter accuracy (about 500 feet) for 95 percent of cellular Phase II 9-1-1 calls. This is also displayed simultaneously on the mapping computer as a pinpointed location, usually a specific address.

If a citizen calls 9-1-1 and is unable to speak to the dispatcher, or if the dispatcher can hear a disturbance in the background, it is considered an "open line." On a Phase II call the address associated with the latitude/longitude coordinates would be entered as a call for service and an officer would be dispatched to the location. A Phase I call necessitates the dispatcher contact the cell provider (Verizon, T- Mobile, etc.) and obtain the billing information associated with the phone number. An officer would then be dispatched to the location of the billing address.

Every effort is made by the dispatcher to attempt contact with an open line or a hang up call.