Computer-aided dispatch
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Computer-aided dispatch (
Methodology
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Computer-assisted dispatch systems use one or more servers located in a central dispatch office, which communicate with computer terminals in a communications center or with mobile data terminals installed in vehicles. There are a multitude of
- Log on/off times of police personnel (sworn/non-sworn)
- Generating and archiving incidents that begin with a phone call from a citizen or originate from personnel in the field
- Assigning field personnel to incidents
- Updating Incidents and logging those updates
- Generating case numbers for incidents that require an investigation
- Timestamping every action taken by the dispatcher at the terminal
In an ideal setting, a call is received by a call-taker and information about the call is inputted into the
A typical
----------------------------------- LOCATION - 1400 Madison RP - Doe, John, 555-5555, 1404 Madison INCIDENT - BURGLARY (in progress) SYNOPSIS - "Caller reports a possible burglary in progress based on seeing individuals inside the residence/Caller advises 2 persons inside the location and call advises the current residents are on vacation." -----------------------------------
Again, granted as it can be seen that the fields are spelled out, the call-taker uses those abbreviations that are already predetermined in order to quickly gather and transmit the information.
The dispatcher then receives the call from the call-taker and is able to dispatch the call to those available. The dispatcher's screen would show the available personnel that are dispatchable. A typical setting can be exemplified by this:
----------------------------------- INCIDENT # - 110001 LOCATION - 1400 Madison RP - Doe, John, 555-5555 INCIDENT - BURGLARY (In Progress) SYNOPSIS - "Caller reports a possible burglary in progress based on seeing individuals inside the residence/Caller advises 2 persons inside the location and call advises the current residents are on vacation." UNITS - 746 (Pri), 749 (Cov) ----------------------------------- Units available - (3) Units out of service - (2) 745 - Avail. 746 - Not Avail. Inc # 554121 747 - Avail. 748 - Avail. 749 - Not Avail. Inc # 554122 -----------------------------------
Everything that is gathered, dispatched and disposed is usually stored in a central server in which the type codes reside, or possibly another server. All of these calls which have incident numbers attached to them can be recalled by an internal search engine. For example, a request for a printout of all calls to Madison in the past hour could be gathered by querying the
Search by: Location LOCATION [ ] --- Result: (Now filled in) Search by: Location LOCATION [14MAD ] --- Result: (1) Incidents
Consoles
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Typical of local government dispatching facilities, the Denver RTD's facility is one example of a transit dispatch center. Communications consoles are mounted in desk-style electronics racks. Features include multi-line telephones. Modern facilities usually include a variety of computing systems for operational and administrative purposes.
Consoles serve as a human interface and connect to push-to-talk dispatch radio systems. Audio from all channels is processed through audio level compression circuits and is routed to two separate speakers identified as select and unselect. Each has a volume control. The select channel or channels carry the highest priority communications. To prevent missed messages on critical channels, the select volume may be configured so it cannot be set to an inaudible level. Unselect channels may be used for special events, other agencies, or purposes that do not involve dispatch and may be inaudible. By pressing a button, any channel on the console can be toggled between select and unselect status. Each channel has an independent push-to-talk button, allowing the dispatcher to talk over one channel at a time. For broadcast messages, a single button transmits over all selected channels at the same time. A digital clock and an LED bar-graph or VU meter are included.
Each channel has a label identifying it and indicator lights and buttons to control settings. A typical channel has a busy light, a call light, select light, select button, and a transmit button. The steady, red busy light indicates another dispatch position is transmitting on the channel. The flashing yellow call light indicates a field unit is talking on the channel. The call light usually blinks for several seconds after a transmission ends allowing a busy dispatcher to look up from a telephone call and determine which channel the last message came from.
Some console dispatch panels are actually a PC-based application. Such is the case of Zetron's Acom system and Avtec's Scout system. This allows for easy customization and modification of the dispatch key layout.
Service levels and geographic information
[edit]Computerized mapping, automatic vehicle location, automatic number identification and caller-identification technology are often used to enhance the service by pinpointing the locations of both the client and the most suitable vehicle for serving the client.
Some
Basic zone system
[edit]The simplest system is a beat or zone map system. For example, in a community with four fire stations, a grid is overlaid on a community map. Each zone of the grid is identified with a progression of police beats, ambulance zones, transit zones, or fire stations.[1] One grid might be labeled: AB241. This means fire station 2, then 4, then 1, then 3 would respond to a fire call occurring inside this zone. The predefined order is created by persons with expertise in the service being provided, local geography, traffic, and patterns in calls for service.
Since only basic GIS information is included, if AVL was available, it would simply display service vehicle locations on a map. The closest unit would be interpreted by the dispatcher looking at vehicle locations projected on the map.
Where detailed geographic data are not available, units may be assigned based on the center of a district. To make the computing problem easier, the
This is the cheapest system to develop because it requires the least detailed geographic information and the simplest calculations. Another problem occurs where several services use the same system. Police and transit, for example, may have different ideas about what boundaries define the ideal zone or how centroids should be weighted.
CAD using geocoding
[edit]Geocoding is a translation system allowing addresses to be converted to X- and Y-coordinates. Someone placing a call for service has an address attached to a wired phone number or tells the dispatcher their address. For example, suppose the caller's address is 123 Main Street.
The GIS or
Again, the system uses a straight-line distance to determine which service vehicle is closest to a call for service. If an AVL system is used, the
This type of system is significantly more expensive than a zone system. The basic system may start with maps from the US Census Bureau or a county assessor's office. The quality of these maps may be good but will not be ideal for dispatching. There would normally be one or more persons on staff who would deal with data changes from new development, new streets, or data quality problems. The person would compile addresses and generate street centerlines in mapping software. Geocoding varies in accuracy depending on data sources and vendors. It normally takes years of work and planning before a system is implemented. Modern geocoded systems will often display service vehicle locations, the location of service calls, and the locations of callers on a map. This helps to disambiguate calls for service and reduces the likelihood of dispatching two reports of a single call for service as two separate calls.
Another problem comes from technologies using differing datums or coordinate systems. For example, suppose your AVL system uses degrees-decimal degrees format. The AVL display for a vehicle at the Heart Butte Post Office in Montana shows a latitude and longitude of 48.28333 N, -112.83583 W. The
Full GIS/AVL integration
[edit]The most expensive and technically challenging systems fully utilize the capabilities of geographic information systems (GIS) and automatic vehicle location (AVL). In these systems, the street centerlines are described as routable. In addition to geocoding and accurate street centerlines, intersections have attributes or scores. Can a service vehicle turn left from eastbound Carnegie Street onto northbound Hooligan Boulevard? A scoring system is used to assess the difficulty of making the turn. At one end of the scoring system there might be an interchange where service vehicles had unrestricted access in making the turn. Perhaps both streets are one-way, making it relatively easy to turn from one onto another. In the middle scores, a left turn might be blocked occasionally by heavy traffic, a draw bridge, or street cars. At the most difficult score, the two streets may cross but the lack of any interchange does not allow service vehicles to get from one to the other.
To calculate the closest service vehicles, the
Routable street centerlines take into account differences between northbound and southbound lanes on a freeway or turnpike. For example, to reach a point in the southbound lanes of a turnpike, service vehicles may need to drive north to the next exit then return on the southbound side. The analysis of a routable street network takes this into account so long as the event location is accurately reported. Routable systems account for barriers like lakes by calculating the distance of the driven route rather than a straight-line distance. It is assumed the service vehicle driver knows the shortest path or that all drivers make similar numbers of wrong turns.
Concentration
[edit]In any system, concentration of facilities increases risks of outages or massive failures. In a system where the call traffic is so high that advanced technology is needed to handle routine levels of day-to-day calls, relatively minor failures can have major effects on service levels. For example, where everyone is used to the convenience of automatic vehicle location (AVL), an AVL outage can suddenly increase staff workloads. Suppose a failure causes a condition where
Data exchange (EDI)
[edit]In public safety systems, standards are under discussion to allow disparate systems to exchange call information. For example, a call taker at the county fire department receives a call for an auto accident inside a city limit. Evolving standards will allow
The usage of EDI applied to
More mature efforts to interconnect
Additional work is occurring under the National Information Exchange Model[5] to link homeland security with
Other interoperability technologies can bridge disparities between the data-format, software, and hardware that constitute various computer-aided dispatch systems in various jurisdictions. Middleware, software and servers (data brokers), can translate and integrate various systems into a seamless automated dispatch system. One example of such middleware (provided by Utah-based FATPOT Technologies/CII)[8] exists in Orange County, Calif., where the Fire Authority has integrated different emergency service answering points into a seamless dispatching network. A similar project was completed for the Silicon Valley Regional Interoperability Project (SVRIP), and is part of the Dept. of Homeland Security's CADIP report.
Australia and New Zealand use the ICEMS protocol for messaging between different
Part of business enterprise computing system
[edit]In business use of
At the high end of enterprise integration for
Recent developments
[edit]Computer aided call handling (CACH) is built on the premise that effective call handling is the foundation for an efficient dispatch response. By using structured call handling and a series of risk calculations, such systems can make objective dispatch recommendations based on information provided by the caller.
See also
[edit]- Emergency medical dispatcher
- EDXL Sharp
- Incident Command System
- Logistics
- Resource Ordering Status System
- Selective calling
References
[edit]Original article
[edit]- Horn, D. W., (2005). An Integrated Public-Safety Computer-Aided Dispatch System. In-press Master's Thesis Project, Regis University, Denver, CO.
Notes
[edit]- ^ This would work for any system including taxis or parcel pick up.
- ^ Associated Public-Safety Communications Officers web site, Data Transfer Committee, Focus Group III. Archived 2006-10-10 at the Wayback Machine The A.P.C.O. refers to this as Project 36.
- ^ Intelligent Transportation Systems
- ^ "IEEE Incident Management Working Group". Archived from the original on 2009-04-19. Retrieved 2009-02-28.
- ^ NIEM.gov
- ^ OASIS EM TC and EDXL Emergency Data Exchange Language
- ^ "Egov.gov". Archived from the original on 2008-09-08. Retrieved 2019-07-08.
- ^ "Fatpot.com". Archived from the original on 2018-07-10. Retrieved 2019-11-13.
- ^ Multiple Applications with Same Infrastructure A Model for Applications, Sourced March 2007.
- ^ System of systems System of Systems
- ^ Ops.fhwa.dot.gov
12.^ https://www.intrado.com/life-safety# is an example of an Emergency Call Handling system that feeds