
A mobile data terminal (MDT) or mobile digital computer (MDC) is a computerized device used in
emergency services,
public transport
Public transport (also known as public transit, mass transit, or simply transit) are forms of transport available to the general public. It typically uses a fixed schedule, route and charges a fixed fare. There is no rigid definition of whic ...
,
taxi
A taxi, also known as a taxicab or simply a cab, is a type of vehicle for hire with a Driving, driver, used by a single passenger or small group of passengers, often for a non-shared ride. A taxicab conveys passengers between locations of thei ...
cabs,
package delivery
Package delivery, or parcel delivery, is the delivery of shipping containers, parcels, or high-value mail in single shipments. The service is provided by most postal systems, express mail, private courier companies, and less-than-truckload shipp ...
,
roadside assistance, and
logistics
Logistics is the part of supply chain management that deals with the efficient forward and reverse flow of goods, services, and related information from the point of origin to the Consumption (economics), point of consumption according to the ...
, among other fields, to communicate with a central
dispatcher
A dispatcher is a Communication, communications worker who receives and transmits information to coordinate operations of other personnel and vehicles carrying out a service. Emergency organizations including police, police departments, fire de ...
. They are also used to display mapping and information relevant to the tasks and actions performed by the vehicle such as CAD drawings, diagrams and safety information.
Mobile data terminals feature a
screen on which to view information and a
keyboard or
keypad
A keypad is a block or pad of buttons set with an arrangement of digits, symbols, or alphabetical letters. Pads mostly containing numbers and used with computers are numeric keypads. Keypads are found on devices which require mainly numeric in ...
for entering information, and may be connected to various
peripheral
A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core compo ...
devices. Standard peripherals include
two-way radio
A two-way radio is a radio transceiver (a radio that can both transmit and receive radio waves), which is used for bidirectional person-to-person voice communication with other users with similar radios, in contrast to a broadcast receiver, whi ...
s and
taximeter
A taximeter or fare meter is a mechanical or electronic device installed in taxicabs and auto rickshaws that calculates passenger fares based on a combination of distance travelled and waiting time. Its shortened form, "taxi", is also a meton ...
s, both of which predate
computer-aided dispatch
Automation describes a wide range of technologies that reduce human intervention in processes, mainly by predetermining decision criteria, subprocess relationships, and related actions, as well as embodying those predeterminations in machine ...
ing. MDTs may be simple display and keypad units, intended to be connected to a separate black-box or AVL (see below) computer. While MDTs were originally
thin client
In computer networking, a thin client, sometimes called slim client or lean client, is a simple (low-Computer performance, performance) computer that has been Program optimization, optimized for Remote desktop, establishing a remote connectio ...
s, most have been replaced with fully functional PC hardware, known as MDCs (Mobile Digital Computers). While the MDC term is more correct, MDT is still widely used. Other common terms include MVC (Motor Vehicle Computer) and names of manufacturers such as iMobile or KDT.
History
During the late 1960s, a surge in crime in the United States spurred the police community to modernize tactics. This led to a push for the adoption of computers by police departments, which would turn out to be a slow process. Some police officials attributed this to a few specific factors including, "the complexities of the new technology, the cautious, conservative nature of many police officers, and citizens' 'fear of Big Brother'. Lack of funds for computer training and equipment maintenance also played a part."
The earliest MDTs began showing up in police cars in the early 1970s. In 1973, the
Cleveland Police Department introduced the specialized
AMC Ambassador
The Ambassador is an automobile manufactured and marketed by American Motors Corporation (AMC) from 1957 through 1974 over eight generations, available in two- and four-door sedan, two-door hardtop, four-door station wagon as well as two-door c ...
Impact task force police car equipped with a Kustom electronics MDT, capable of checking for license numbers or owner information, stolen vehicles, verifying wanted persons, and exchange private messages between vehicles. These would be the first police computers to be used in the
State of Ohio.
Motorola would become a major provider of MDTs by the late 1970s. One of these earliest models was the D-1118, which would be succeeded by the MDT-9100 in the 1980s. By the early 1990s, police departments began to increasingly use computers for more advanced activities, as opposed to routine patrol tasks that accounted for the typical modicum of usage. According to Bureau of Justice statistics, there was a considerable uptake in adoption between 1990 and 1993, with one half of departments using computers compared to two thirds by 1993. Police departments with computers staffed approximately 95 percent of local officers by 1993.
These early police computers, including those developed by Motorola, became notorious for security issues due to the relatively basic data protocol used. Despite Motorola's marketed appearance of secure communications, it was soon discovered that this conspicuous “special code” for bit interleaving and data stream obfuscation was nothing more than simple
ASCII
ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control c ...
. This approach taken by Motorola would have been considered
security by obscurity. In the 1990s, hackers deciphered the properties of the protocol and PC programs soon began appearing on the market allowing the general public to monitor police communications - an issue that lasted well into the 2000s.
Technology
In the earlier days of
computer-aided dispatching (CAD), many MDT's were custom devices, used with specialized point to point radios, particularly in applications such as police dispatching. While applications like taxi and package delivery often still use custom designed terminals, the majority of CAD systems have switched to
ruggedized laptops and Wide-Area Wireless IP communications, utilizing the Internet or private IP networks connected to and over it.
For industrial applications such as commercial trucking,
GIS, agriculture, mobile asset management, and other industries, custom electronic hardware is still preferred. Custom terminals use I/O interfaces that connect directly to industry-specific equipment. They are usually environmentally hardened packages with power supply protection and robust memory file systems that greatly improve reliability and task efficiency. MDT solutions that are based on ruggedized consumer products or consumer available software will typically not have the life cycle duration expected in industrial applications, over five years.
Typical features
* 9 VDC to 36 VDC input power.
* May be tablet convertible.
* Serial ports to connect to a satellite or terrestrial radio transceiver.
* Digital I/O to monitor external events.
* Removable medial or I/O port of retrieving data or upgrading software.
* Wide
operating temperature
An operating temperature is the allowable temperature range of the local ambient environment at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the de ...
of to or greater.
* Water and dust resistance rated.
* Drop tested and rated.
* Sealed against dust and liquid.
* Connections to industry specific equipment, such as J1708 data bus for commercial truck applications.
* Display technology specific to viewing conditions for the intended industry (
LCD
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers to display information. Liquid crystals do not em ...
,
TFT LCD
A thin-film-transistor liquid-crystal display (TFT LCD) is a type of liquid-crystal display that uses thin-film transistor, thin-film-transistor technology to improve image qualities such as addressability and contrast. A TFT LCD is an active mat ...
,
Vacuum fluorescent display,
CSTN).
* Integrated
uninterruptible power supply
An uninterruptible power supply (UPS) or uninterruptible power source is a type of continual power system that provides automated backup electric power to a electrical load, load when the input power source or mains electricity, mains power fai ...
, which will ride through electrical brown-outs typical in vehicle installations.
* 802.11 transceiver (depending on target application), possibly with external antenna connection.
* Cellular transceiver providing an Internet connection.
A related device classification, specific to the transportation industry, is called
automatic vehicle location (AVL). Mobile data terminals are often used in conjunction with a "black box" that contains a GPS receiver, cell phone transceiver, other radio devices, or interfaces to industry-specific equipment. AVL devices may be simple stand-alone modems or may include operating systems with application space for the system integrator.
Use in vehicle
MDTs are most commonly associated with in-vehicle use. This requires the MDT to be anchored to the vehicle for driver safety, device security, and user ergonomics. Mounts are designed for attaching MDTs to mobile workspaces into, most notably: automobiles, forklifts, boats, and planes. MDTs generally require specific installation protocols to be followed for proper ergonomics, power and communications functionality. MDT installation companies such as PCN Strategies, USAT Corp. and TouchStar Technologies UK, specialize in designing the mount design, assembling the proper parts, and installing them in a safe and consistent manner away from airbags, vehicle HVAC controls, and driver controls. Frequent installations will include a
WAN modem, power conditioning equipment, and a WAN, WLAN, and GPS antenna mounted external to the vehicle.
Use in UK ambulance services
The mobile data terminal (MDT) allows for routing, receiving and display of data between control room and operational vehicles allowing ambulance crews to respond quickly and appropriately to calls. This allows for up to date CAD information to be dispatched instantly to the receiving ambulance saving valuable time in receiving critical information about the incident. Its mapping software allows for accurate location of the incident to be transmitted directly to the ambulance as well as plotting the quickest route to the scene. This software also allows for the control room to track all operational vehicles to identify which available ambulance is closest to the scene of an incident allowing for the closest appropriate resource to be dispatched.
Other benefits of the MDT are:
* Booking on system to identify which staff member is currently on the vehicle.
* Status updates, allowing the crew to inform the control room of their current status on an incident via a touchscreen menu rather than informing them over the radio.
* 2-way text conversation with the control room to decrease unnecessary radio demand.
* Request additional payment for soiled uniform when clothing is contaminated.
* Further options can be added such as the ability to download apps so crews can watch entertainment or order food delivery when on standby.
See also
*
Portable data terminal
References
{{Computer sizes
Automotive software
Mobile computers
Automatic identification and data capture