Introduction


For many years emergency dispatching for police, fire and emergency medical services was all done manually. Dispatchers were expected to talk on the telephone to the person calling, along with talking on the radio. They had to decide who and/or what units to send and keep track of all the responding units and their needs, keeping everything on just a pad of paper and a header card. The dispatcher also had to keep track of the other units within the system and their calls and needs. Computer technology has taken this process rapidly into the future. Let me take you through what the Computer Aided Dispatching system, or CAD, is and how it has enhanced the delivery of emergency services.
Without the advent of this technology, emergency services dispatching would most likely collapse due to the overload. Demands for emergency services have risen sharply, and humans can only process this deluge of information and make assignments at a certain speed. CAD has taken us far ahead of that. It helps us to efficiently select units, prioritize calls, and provides directions and information to responding personnel. Let me show you what makes CAD tick.







Enhanced 911

Enhanced 911 systems are an integral part of the modern Computer Aided Dispatch (CAD) systems. Nearly ninety-eight percent of all the communities in the United States are now served by 911 as the access to emergency services. Of that, over eighty percent employ Enhanced 911 technology. It is soon hoped that one hundred percent of our communities will have 911 access and one hundred percent will employ Enhanced 911.
Enhanced 911, or E 9-1-1, is very similar to the caller ID which most of us have in our homes. However, it goes further in the offering of information to the 911 call taker. After only one ring when the call taker lifts the receiver or presses the connect button a wealth of information appears. The information is displayed on a screen the size of a 10” television included are the callers name (in calling from a home), address and apartment or building numbers. This means that during a time of high stress to the caller the operator merely needs to verify the information, and not try to illicit it from someone who is excited, hurt, sick or in danger. If the caller is unable to speak, this ability to pull up the name and/or address information and connect it with police, fire and medical could, and has, made the difference between a life saved and someone dying. Calls made from pay phones display the address and location from which the call is being placed.

Once the operator has verified the caller’s information, he or she may add any pertinent comments made by the caller, to a CAD screen, also at their position. This information includes the problem, special instructions and updates as received.
As the type of call is entered, the CAD sorts it for the type or kind and assigns the appropriate type of emergency response, such as police, fire or rescue, or any combination indicated. The operator then presses a one-button transfer, which in a nano second transmits the call to the dispatch position. The operator may keep the caller on the line to update the information or get more in-depth information, as indicated by the type of call.


CAD to the Rescue
The next step is for the CAD system to take over the call and make many decisions within 3 seconds. What are the kinds of decisions CAD has to make? Which city is the call in? What resources are required and who is available to respond? Who is next to respond if additional help is needed or requested? In many cases, CAD will also decide who is the closest unit through automatic vehicle location technology.
The CAD operates on a database known as a geofile. This file contains all street addresses and response protocols for a given jurisdiction or district within

that jurisdiction. These databases are massive and it is a time consuming job to construct initially. In a city, which may be experiencing a lot of new construction, the CAD database must be updated weekly or monthly to reflect any new roads and addresses? CAD is only as good as the information