E-911 Calls’ Points Of Origin Now Displayed For Dispatchers

By Andrew Gorosko

The town’s emergency dispatch center has added a new electronic tool to its communications array designed to visualize the points of origin of the E-911 telephone calls that are placed to the center.

Knowing the location from which a cellular telephone call is placed to the dispatch center is expected to help police, fire, and ambulance staffers find E-911 callers who are unfamiliar with the area from which they are calling. Such people would include those from elsewhere who are passing through town on Interstate 84, or on state roads, who are unfamiliar with the area, and thus have difficulty describing their location to E-911 dispatchers. It also would include people who are lost in the two large state forests in town.

Town Director of Emergency Communications Joseph DelBuono said this week that the emergency dispatch center in the police station had the E-911 mapping system installed earlier this month. About two-thirds of the towns in the state are now using the system, with all municipalities slated to be using the new equipment by September, Mr DelBuono said.

The Office of Statewide Emergency Telecommunications (OSET) is overseeing the installation of E-911 mapping equipment throughout Connecticut. Newtown’s installation cost approximately $35,000. The costs are covered by 911 fees that are levied on individual telephone bills. 

The town receives about 7,000 E-911 calls annually, averaging about 20 such calls a day.

The E-911 mapping system employs two computer monitors, one of which uses an electronic map to display a call’s point of origin. The other monitor displays technical information about the telephone call.

“It allows you to locate a caller on map,” Mr DelBuono said.

The point of origin of calls that are placed to the 911 dispatch center from conventional telephones, which are known as “land lines,” generally are accurately depicted on the electronic mapping, Mr DelBuono said.

But some cellular telephone companies have some work to do to get their communications networks into compliance with the new mapping equipment, he said.

The telecommunications networks operated by Cingular, AT&T, and Verizon have provided the dispatch center with fairly accurate depictions of their callers’ points of origins, generally specifying a geographic point that is within between 200 feet and 800 feet of the call’s point of origin, Mr DelBuono said.

The Sprint telecommunications system currently states only the cellular telecommunications tower that is the closest tower to a caller as an E-911 call’s point of origin, he said.

Nextel is working out some electronic bugs in its system, so the mapping function is not currently working with Nextel cellular telephones, he said.

T-Mobile’s mapping function is not currently working, Mr DelBuono said.

Accuracy Concerns

Pointing out that the E-911 mapping system is new, Mr DelBuono said concerns have arisen about the accuracy of its mapping.

Although the system is clearly in need of improvement, having access to the system is better than not having access to it, Mr DelBuono said. The state is developing a process through which mapping system problems would be formally reported and later repaired, he said.

After a call arrives on the E-911 mapping system, dispatchers recheck the point of origin of the call, in a process that generally provides more accurate information about a caller’s location. Such rechecking also shows dispatchers the direction of travel of a moving motor vehicle from which a cellular telephone call is placed.

Cellular telephone companies use various technologies, such as electronic triangulation, in describing the location of a caller to the E-911 mapping system.

Although the new mapping gear has yet to be perfected, Mr DelBuono said, “It’s definitely a positive piece of equipment.”

Mr DelBuono said he expects the mapping accuracy to increase as the system becomes more reliable through improvements during the next two to three years. Consequently, dispatchers do not now assume that the electronic map location that is displayed with an incoming E-911 call is accurate, but double-check the information, he said.

“It’s definitely going to enhance the safety of people in town, and the people coming through town,” Mr DelBuono said.