C·A·P PHOENIX STYLE
COMMUNICATIONS
photo by Nancy Engebretson
The Phoenix, Ariz., Fire Department has the most modern computer-aided dispatch system of any fire department in North America. When the system started in 1981, Phoenix also took over communication responsibilities for the neighboring cities of Tempe and Glendale, increasing the effectiveness of the automatic aid network which has served the three cities for over five years. The CAD facility serves an area of over 500 square miles and 1 million population with continuing growth projected over the next 20 years. The system is designed to accommodate growth in the three cities and the possible addition of other jurisdictions as the automatic aid network expands.
The CAD facility replaces Phoenix’s 22year-old communication system which had simply been overwhelmed by the city’s growth and the emergency workload. Originally designed to handle up to 20,000 calls per year, the old system processed over 70,000 in its last year of operation. Recognizing the need to modernize the communications system, Fire Chief Alan Brunacini appointed a task force of department personnel to study the needs and the state of the art in public safety communications in 1978. The task force visited new communications facilities in other cities and spend nearly a year developing a basic concept of the system that would serve the needs of Phoenix most effectively. The concept plan took advantage of the lessons learned by other cities, both positive and negative.
In 1979 Phoenix began preparations for a city bond election, with a computer-aided dispatch system listed as the number one priority of the fire department. The basic concept plan and budget were carefully scrutinized by a citizens’ bond committee before being endorsed for the public ballot. By the end of May the fire department had the approval of the voters, with over 85 percent supporting the $5-million expenditure.
The extremely positive image of the Phoenix Fire Department in the community, particularly the emergency medical service program, was instrumental in gaining public support at a time when bond issues have become politically unpredictable.
With funding assured, work began in earnest to get the system built quickly and within the $5-million budget. Project Director john Simmons was recruited to head the team. Simmons had designed and built the previous system as a fire department employee, then went on to head communications development projects for the city’s public works department.
Joining Simmons was Captain Larry Husemann, a veteran fire fighter and computer programming expert who had worked on the concept plan. They spent six months preparing a comprehensive Request for Proposal (RFP) document, one of the essential elements of the project, which precisely defined the operating requirements and performance criteria for the system. Qualified bidders were invited to bid on the complete package: hardware, software, installation documentation and training on a turnkey basis. The proposal from Planning Research Corporation of San Francisco was ultimately accepted.
PRC contracted to supply the entire system, ready to operate, in less than two years and within the estimated budget. When the system came on line, it was still within the budget and only four weeks behind the original schedule (an unbelievable feat for a project as large and expensive as Phoenix CAD).
The contract with PRC called for a completely new communications system and several features which had never been used previously in a public safety communications system. Putting the package together called for extensive interaction on a continual basis between the contractor and the fire department. Numerous subcontractors were involved in different phases of the project, requiring precise coordination and scheduling. Several additional specialists were recruited to help coordinate the project for the fire department.
Captain Don Drury was assigned to manage the development of the facility, making sure that everything was constructed according to plans and specifications. This included working with an interior designer who was hired to create a pleasant work environment for the six to eight personnel who occupy the center at all times. This resulted in a facility which is anything but the traditional sterile communications center — designed to reduce fatigue and instill pride in the people who work there. The dispatchers can look out over the city from their consoles or step out onto the balcony for a breath of fresh air.
The software used in the Phoenix CAD system was required to meet demanding specifications, including the ability to process a minimum of six incidents per minute for 60 minutes. The program which selects units for dispatch was written by Husemann, who was intimately involved in the software development. Phoenix uses a complex unit selection subsystem which matches the service capability of different units with the needs of a particular type of emergency incident. With this system, any company can be designated as a paramedic unit or as having a particular type of apparatus or equipment that would be needed at different types of incidents. The unit capability designations can be changed by a single keyboard transaction and the number and type of units for a particular incident may be adjusted at any time.
No more running cards
The dispatch routine does away with traditional running cards in favor of a fully dynamic system. The computer is programmed with the distance for each fire station to each geographic location in the city. To select units for an incident, the computer determines the capabilities required (advanced life support, hazardous materials, extrication tools, etc ) and finds the closest units with those capabilities at the particular moment.
The system not only serves the dispatch needs of the Phoenix Fire Department, but also provides a computer and telecommunications system for numerous other functions. The system includes three identical Digital PDP 11 /44 minicomputers, any one of which can handle all dispatch functions. While the second computer shadows the first, to take over in case of failure, the third is available for processing incident reports, maintaining occupancy records for fire prevention inspections, personnel records, leave scheduling, equipment inventories and management reporting. The capabilities of the auxiliary data processing functions will be developed over a period of several years, taking advantage of capabilities designed into the project for future use. Husemann and programmer/analysts Dan Hudson and Paula McMann are involved in the ongoing development of these systems, including an interface with the city’s centralized computer system. The redundant computer capability in the CAD system is designed so that any one of the three computers can perform any function, giving the CAD system a reliability of over 99.98 percent.
Radio and telecommunications improvements were a major portion of the project. Installation and testing of this equipment was supervised by Herb Legendre, a communications engineer who also came from the public works department. Legendre currently heads a staff of four technicians responsible for service and maintenance of the system hardware.
Photos by Nancy Engebretson
One of the most exciting features of the system is the introduction of mobile digital terminals (MDTs) in all first line apparatus and command vehicles. A dedicated 800 MHz radio channel links 140 of these terminals to the main computer. Each terminal has status buttons which transmit routine messages directly to the computer (responding, on scene, available on radio, available in quarters, etc.) plus a full keyboard to communicate with the computer or any other terminal in the network.
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The mobile terminals have a 5-inch video screen that can display 315 characters of text or graphics per page. When units are dispatched to an incident, the system automatically loads up to 10 pages of information into the storage buffers of their MDTs. This information includes the location, time and details of the call, a list of responding units, map coordinates, assigned radio channel and the incident number. If there is an occupancy file for the address of the incident in the system, it will also transmit data including responsible party names and numbers, building contents, fire protection systems, site plans, floor plans, hydrant locations and utility shut-offs. The officer in command of an incident can type comments on the diagrams and transmit them to other units on the call or instruct the system to dispatch or recall other units. The whole system is capable of functioning without voice radio communications.
Each fire station and administrative site has a video terminal and a printer to receive dispatch messages and interact with the computer system. Any terminal can update files, enter reports, query the system for the status of units or active incidents and send or receive messages from any terminal in the system, fixed or mobile. This has eliminated much of the routine paperwork in fire stations as reports are entered directly into the terminals. This aspect of the system was particularly well received by personnel in the stations.
The 12 dispatch consoles are designed to provide the full capability of the system from each position. Currently, a maximum of eight positions are in use during peak periods, while the others are available for future expansion, training or major emergencies. Each position has two color video screens —one for entering information and the other for monitoring the current status of units and incidents. The left bank of the console provides pushbutton telephone switching, while the right side includes the radio control panel and voice alarm circuit controls. The computer automatically sends the video display and printer message to dispatched units, turns on lights and speakers in the stations, selects the proper radio channel and waits for the units to acknowledge response.
The radio control panels include a microprocessor which allows each dispatcher to select transmitter sites, monitor 45 channels and transmit on any combination of 20 VHF and UHF channels, independent of the other positions. Telephone patches, channel-to-channel patches and medicto-hospital patches can be set up by pushbutton controls.
The fire station packages include microprocessors which can control up to 30 separate functions in each station. Future plans call for alarm systems, door openers and other equipment to be linked directly to the CAD system. The 43 stations are currently linked to the main system via leased telephone lines, but these will probably be replaced by microwave links to reduce cost and increase reliability. This will depend on a future bond election.
Automatic aid
Glendale and Tempe have each contracted with Phoenix for dispatch and communications operations. Each city purchased and maintains its own hardware as part of the plan and is responsible for updating its own geofiles and data bases. The three cities use identical fireground procedures, and units are dispatched without regard to boundary lines between the three jurisdictions. The automatic aid network functions much more effectively with one communications system. All three cities are represented on the committees which establish and update procedures.
With the capability of the CAD system, Phoenix was able to absorb the communications workload for the other two cities with no increase in staffing. Dispatchers from Glendale and Tempe were reassigned within their organizations and each city pays a share of the total operating cost of the new system. The net cost to Glendale and Tempe is approximately half the cost of maintaining their own dispatch offices.
The introduction of a system of this complexity requires extensive training and planning. Prior to going on line, dispatch personnel spent a minimum of 120 hours learning how to use the system in a simulation mode. The dispatchers were also used to perform many of the acceptance tests, gaining more valuable experience under simulated problem and overload situations.
The system has a captain assigned as a full-time instructor for companies in the field, helping them learn the enhancements of the system on an incremental basis. The growing uses of the system make training a major ongoing project. Several captains act as part-time instructors and quality control experts to help with the training.
The Phoenix Fire Department feels that it has made a great investment in the CAD system. The innovations involved in the project have drawn interest from many other cities which are planning their own CAD projects for installation over the next few years.
In operation, the system is impressive. It greatly increases the efficiency of dispatch personnel, allowing them to handle several working incidents at the same time and process calls in high-activity periods without significant delay or backlog. In acceptance tests, it performed flawlessly and proved itself on record-breaking activity periods resulting from summer storms and the July 4 celebrations. While the dispatch time for individual incidents was not significantly reduced, the ability to handle higher volumes of activity was greatly increased. The increased volume capability and the advances in providing data support for emergency operations, make the system a tremendous success.
