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Automatic Vehicle Location
Automatic vehicle location (AVL or ~locating; telelocating in EU) is a means for automatically determining and transmitting the geographic location of a vehicle. This vehicle location data, from one or more vehicles, may then be collected by a vehicle tracking system to manage an overview of vehicle travel. As of 2017, GPS technology has reached the point of having the transmitting device be smaller than the size of a human thumb (thus easier to conceal), able to run 6 months or more between battery charges, easy to communicate with smartphones (merely requiring a duplicate SIM card from one's mobile phone carrier in most cases) — all for less than $20 USD. Most commonly, the location is determined using GPS and the transmission mechanism is SMS, GPRS, or a satellite or terrestrial radio from the vehicle to a radio receiver. A single antenna unit covering all the needed frequency bands can be employed. GSM and EVDO are the most common services applied, because of the low da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geographic Coordinate System
A geographic coordinate system (GCS) is a spherical coordinate system, spherical or geodetic coordinates, geodetic coordinate system for measuring and communicating position (geometry), positions directly on Earth as latitude and longitude. It is the simplest, oldest, and most widely used type of the various spatial reference systems that are in use, and forms the basis for most others. Although latitude and longitude form a coordinate tuple like a cartesian coordinate system, the geographic coordinate system is not cartesian because the measurements are angles and are not on a planar surface. A full GCS specification, such as those listed in the EPSG Geodetic Parameter Dataset, EPSG and ISO 19111 standards, also includes a choice of geodetic datum (including an Earth ellipsoid), as different datums will yield different latitude and longitude values for the same location. History The invention of a geographic coordinate system is generally credited to Eratosthenes of Cy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and Admiralty law, law enforcement military branch, service branch of the armed forces of the United States. It is one of the country's eight Uniformed services of the United States, uniformed services. The service is a maritime, military, multi-mission service unique among the United States military branches for having a maritime law enforcement mission with jurisdiction in both domestic and international waters and a Federal government of the United States, federal regulatory agency mission as part of its duties. It is the largest coast guard in the world, rivaling the capabilities and size of most Navy, navies. The U.S. Coast Guard protects the United States' borders and economic and security interests abroad; and defends its sovereignty by safeguarding sea lines of communication and commerce across U.S. territorial waters and its Exclusive economic zone, Exclusive Economic Zone. Due to ever-ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 machines. Automation has been achieved by various means including mechanical, hydraulic, pneumatic, electrical, electronic devices, and computers, usually in combination. Complicated systems, such as modern factories, airplanes, and ships typically use combinations of all of these techniques. The benefit of automation includes labor savings, reducing waste, savings in electricity costs, savings in material costs, and improvements to quality, accuracy, and precision. Automation includes the use of various equipment and control systems such as machinery, processes in factories, boilers, and heat-treating ovens, switching on telephone networks, steering, stabilization of ships, aircraft and other applications and vehicles with reduced huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Digital Enhanced Network
Integrated Digital Enhanced Network (iDEN) is a mobile telecommunications technology, developed by Motorola, which provides its users the benefits of a trunked radio and a cellular telephone. It was called the first mobile social network by many technology industry analysts. iDEN places more users in a given spectral space, compared to analog cellular and two-way radio systems, by using speech compression and time-division multiple access (TDMA). History The iDEN project originally began as MIRS (Motorola Integrated Radio System) in early 1991. The project was a software lab experiment focused on the utilization of discontiguous spectrum for GSM wireless. GSM systems typically require 24 contiguous voice channels, but the original MIRS software platform dynamically selected fragmented channels in the radio frequency (RF) spectrum in such a way that a GSM telecom switch could commence a phone call the same as it would in the contiguous channel scenario. Operating frequenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sprint Nextel
Sprint Corporation was an American telecommunications company. Before being Merger of Sprint Corporation and T-Mobile US, acquired by T-Mobile US on April 1, 2020, it was the fourth-largest mobile network operator in the United States, serving 54.3 million customers as of June 30, 2019. The company also offered wireless voice, messaging, and broadband services through its various subsidiaries under the Boost Mobile and Open Mobile brands and wholesale access to its wireless networks to mobile virtual network operators. In July 2013, majority ownership of the company was purchased by the Japanese telecommunications company SoftBank Group. Sprint used CDMA2000, CDMA, EvDO and 4G LTE networks, and formerly operated iDEN, WiMAX, and 5G NR networks. Sprint was incorporated in Kansas. Sprint traced its origins to the Brown Telephone Company, which was founded in 1899 to bring telephone service to the rural area around Abilene, Kansas, Abilene, Kansas. In 2006, Sprint left the local la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 department, fire departments, and emergency medical services, emergency medical services departments as well as civilian organizations such as motorcycle couriers, taxicab providers, Truck driver, trucking companies, railroads, bus systems, and public utility companies, use dispatchers to relay information, direct personnel, and coordinate their operations. Types of dispatchers Emergency dispatchers An emergency dispatcher, also known as public safety dispatcher, 9-1-1 dispatcher, or public safety telecommunicator www.bls.gov ''Occupational Employment and Wages May 2020''. URL accessed on August 19, 2021 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Call Center
A call centre (English in the Commonwealth of Nations, Commonwealth spelling) or call center (American English, American spelling; American and British English spelling differences#-re, -er, see spelling differences) is a managed capability that can be centralised or remote that is used for receiving or transmitting a large volume of enquiries by telephone. An inbound call centre is operated by a company to administer incoming product or service support or information inquiries from consumers. Outbound call centres are usually operated for sales purposes such as telemarketing, for solicitation of charitable or political donations, debt collection, market research, emergency notifications, and urgent/critical needs blood banks. A contact centre is a further extension of call centres telephony based capabilities, administers centralised handling of individual communications, including Letter (message), letters, faxes, live support software, social media, instant message, and email ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acknowledgement (data Networks)
In data networking, telecommunications, and computer buses, an acknowledgement (ACK) is a signal that is passed between communicating processes, computers, or devices to signify acknowledgment, or receipt of message, as part of a communications protocol. Correspondingly a negative-acknowledgement (NAK or NACK) is a signal that is sent to reject a previously received message or to indicate some kind of error. Acknowledgments and negative acknowledgments inform a sender of the receiver's state so that it can adjust its own state accordingly. Acknowledgment signal types The ASCII code point for ACK is 0x06 (binary 0000 0110). By convention a receiving device sends an ACK to indicate it successfully received a message. ASCII also provides a NAK code point (0x15, binary 0001 0101) which can be used to indicate the receiving device cannot, or will not, comply with the message. Unicode provides visible symbols for these ASCII characters, U+2406 (␆) and U+2415 (␕). ACK and NAK s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thoroughfare
A thoroughfare is a primary passage or way of transport, whether by road on dry land or, by extension, via watercraft or aircraft. Originally, the word referred to a main road or open street which was frequented thoroughly. Different terms *Roads, route or way on land between two places that has been paved or otherwise improved for travel * Boardwalk * Boulevard, particularly in North American usage * Bridle path, for equestrian use * Canopy walkway * Cycleway, for use by cyclists *Footpath, for use only by pedestrians * Foreshoreway, a greenway along the edge of the sea, open to both walkers and cyclists * Greenway, a wilderness area intended for "passive use" * Highway, depending on jurisdiction, anything from a path (England) to a road restricted to fast motor vehicles * Hiking trail, trails (footpaths), in the countryside *Long-distance trail, recreational trail of exceptional length (between 50 km and 1,000 km or more) mainly through rural areas used for hiking, backpacking, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transponder
In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a flight transponder is an automated transceiver in an aircraft that emits a coded identifying signal in response to an interrogating received signal. In a communications satellite, a satellite transponder receives signals over a range of uplink frequencies, usually from a satellite ground station; the transponder amplifies them, and re-transmits them on a different set of downlink frequencies to receivers on Earth, often without changing the content of the received signal or signals. Satellite/broadcast communications A communications satellite’s channels are called transponders because each is a separate transceiver or repeater. With digital video data compression and multiplexing, several video and audio channels may travel through a single tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trolley Pole
A trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" (electrified) overhead line, overhead wire to the control and the electric traction motors of a tram or trolley bus. It is a type of current collector. The use of overhead wire in a system of current collection is reputed to be the 1880 invention of Frank J. Sprague, but the first working trolley pole was developed and demonstrated by Charles Joseph Van Depoele, Charles Van Depoele, in autumn 1885.William D. Middleton, Middleton, William D. (1967). ''The Time of the Trolley'', pp. 63–65, 67. Milwaukee: Kalmbach Publishing. . History An early development of an experimental tramway in Toronto, Ontario, was built in 1883, having been developed by John Joseph Wright (inventor), John Joseph Wright, brother of swindler Whitaker Wright. While Wright may have assisted in the installation of electric railways at the Canadian National Exhibition (CNE), and may even have used a pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise
Noise is sound, chiefly unwanted, unintentional, or harmful sound considered unpleasant, loud, or disruptive to mental or hearing faculties. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arises when the brain receives and perceives a sound. Acoustic noise is any sound in the acoustic domain, either deliberate (e.g., music or speech) or unintended. In contrast, noise in electronics may not be audible to the human ear and may require instruments for detection. In audio engineering, noise can refer to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as a hiss. This signal noise is commonly measured using A-weighting or ITU-R 468 weighting. In experimental sciences, noise can refer to any random fluctuations of data that hinders perception of a signal. Measurement Sound is measured based on the amplitude and frequency of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
