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EDACS
The Enhanced Digital Access Communication System (EDACS) is a radio communications protocol and product family invented in the General Electric Corporation in the mid 1980s. History A young designer, Jeff Childress, created an autonomous radio base-station controller, known as the GETC (General Electric Trunking Card). The GETC was a general-purpose controller with input/output optimized for radio system applications. Childress and the team demonstrated that a smart controller could be adapted to a variety of applications, but his interest was really in fault tolerance. The competition dealt with fault tolerance by means of the "brute force and ignorance" approach, deploying double the hardware for their controllers, and interconnecting them with massive and problematic relay banks . The EDACS system architecture supported large communications footprints. By making the GETC's "trunk" among themselves, one GETC per channel, the system was designed to be inherently fault-t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trunked Radio Systems
A trunked radio system is a two-way radio system that uses a control channel to automatically assign frequency channels to groups of user radios. In a traditional half-duplex land mobile radio system a group of users (a ''talkgroup'') with mobile and portable two-way radios communicate over a single shared radio channel, with one user at a time talking. These systems typically have access to multiple channels, up to 40-60, so multiple groups in the same area can communicate simultaneously. In a conventional (non-trunked) system, channel selection is done manually; before use the group must decide which channel to use, and manually switch all the radios to that channel. This is an inefficient use of scarce radio channel resources because the user group must have exclusive use of their channel regardless of how much or how little they are transmitting. There is also nothing to prevent multiple groups in the same area from choosing the same channel, causing conflicts and 'cross-talk'. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M/A-COM Inc
MACOM Technology Solutions is a developer and producer of radio, microwave, and millimeter wave semiconductor devices and components. The company is headquartered in Lowell, Massachusetts, and in 2005 was Lowell's largest private employer. MACOM is certified to the ISO 9001 international quality standard and ISO 14001 environmental standard. The company has design centers and sales offices in North America, Europe, Asia and Australia. History Early history MACOM was founded in the 1950s as Microwave Associates by the engineers Vessarios Chigas, Louis Roberts, Hugh Wainwright and Richard M. Walker. The company was initially a small supplier of magnetrons to the U.S. Army Signal Corps. The name was changed to M/A-COM in 1978 to reflect the company's growing involvement in the telecommunication industry and the merger with DCC, Digital Communications Corporation. During this timeframe, the company produced low power wideband RF amplifier modules for use in test & measurement. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M/A-COM
MACOM Technology Solutions is a developer and producer of radio, microwave, and millimeter wave semiconductor devices and components. The company is headquartered in Lowell, Massachusetts, and in 2005 was Lowell's largest private employer. MACOM is certified to the ISO 9001 international quality standard and ISO 14001 environmental standard. The company has design centers and sales offices in North America, Europe, Asia and Australia. History Early history MACOM was founded in the 1950s as Microwave Associates by the engineers Vessarios Chigas, Louis Roberts, Hugh Wainwright and Richard M. Walker. The company was initially a small supplier of magnetrons to the U.S. Army Signal Corps. The name was changed to M/A-COM in 1978 to reflect the company's growing involvement in the telecommunication industry and the merger with DCC, Digital Communications Corporation. During this timeframe, the company produced low power wideband RF amplifier modules for use in test & measurement. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenSky
OpenSky is a registered trademark of Harris Corporation and is the trade name for a wireless communication system, invented by M/A-COM Inc., that is now a division of Harris RF Communications. OpenSky technology applies voice over IP transport to radio communications applications in a unique architecture. In the mid-1990s Federal Express invited proposals for a data and voice network to the vehicular level. As the world's largest shipper, FedEx was a key opportunity, and major market players presented their existing product offerings over some time. M/A-COM presented their concept, and won the business. They delivered a standards-based infrastructure that attempted to leverage open systems to the largest degree possible, while adapting specific input/output to meet the customer's exact requirements. OpenSky received the direct attention of Tyco Electronics when they acquired it along with AMP Inc. Tyco Electronics funded the company to acquire the EDACS radio system team and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Voice Systems
Digital usually refers to something using discrete digits, often binary digits. Technology and computing Hardware *Digital electronics, electronic circuits which operate using digital signals **Digital camera, which captures and stores digital images ***Digital versus film photography **Digital computer, a computer that handles information represented by discrete values **Digital recording, information recorded using a digital signal Socioeconomic phenomena *Digital culture, the anthropological dimension of the digital social changes * Digital divide, a form of economic and social inequality in access to or use of information and communication technologies * Digital economy, an economy based on computing and telecommunications resources Other uses in technology and computing * Digital data, discrete data, usually represented using binary numbers *Digital marketing, search engine & social media presence booster, usually represented using online visibility. * Digital media, media ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vocoder
A vocoder (, a portmanteau of ''voice'' and ''encoder'') is a category of speech coding that analyzes and synthesizes the human voice signal for audio data compression, multiplexing, voice encryption or voice transformation. The vocoder was invented in 1938 by Homer Dudley at Bell Labs as a means of synthesizing human speech. This work was developed into the channel vocoder which was used as a voice codec for telecommunications for speech coding to conserve bandwidth in transmission. By encrypting the control signals, voice transmission can be secured against interception. Its primary use in this fashion is for secure radio communication. The advantage of this method of encryption is that none of the original signal is sent, only envelopes of the bandpass filters. The receiving unit needs to be set up in the same filter configuration to re-synthesize a version of the original signal spectrum. The vocoder has also been used extensively as an electronic musical instrument. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
APCO-25
Project 25 (P25 or APCO-25) is a suite of standards for interoperable digital two-way radio products. P25 was developed by public safety professionals in North America and has gained acceptance for public safety, security, public service, and commercial applications worldwide. P25 radios are a direct replacement for analog UHF (typically FM) radios, but add the ability to transfer data as well as voice, allowing for more natural implementations of encryption and text messaging. P25 radios are commonly implemented by dispatch organizations, such as police, fire, ambulance and emergency rescue service, using vehicle-mounted radios combined with repeaters and handheld walkie-talkie use. Starting around 2012, products became available with the newer phase 2 modulation protocol, the older protocol known as P25 became P25 phase 1. P25 phase 2 products use the more advanced AMBE2+ vocoder, which allows audio to pass through a more compressed bitstream and provides two TDMA voice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IMBE
Imbe may refer to: * Imbe (tree), a fruit tree native to Africa * Imbe, Okayama, a township in Japan ** Imbe Station is a railway station in Imbe, Bizen, Okayama Prefecture, Japan. Lines *West Japan Railway Company ** Akō Line Layout *Kan'i itaku station A , sometimes abbreviated as , is a form of railway station in Japan which is operated by an entit ... * Imbé, a municipality in Rio Grande do Sul, Brazil * Imbé de Minas, a municipality in Minas Gerais, Brazil * Imbé River, a river in Rio de Janeiro, Brazil * Improved multi-band excitation, or IMBE, a speech coding standard {{Disambiguation, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TETRA
Terrestrial Trunked Radio (TETRA; formerly known as Trans-European Trunked Radio), a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification. TETRA was specifically designed for use by government agencies, emergency services, (police forces, fire departments, ambulance) for public safety networks, rail transport staff for train radios, transport services and the military. TETRA is the European version of trunked radio, similar to Project 25. TETRA is a European Telecommunications Standards Institute (ETSI) standard, first version published 1995; it is mentioned by the European Radiocommunications Committee (ERC). Description TETRA uses time-division multiple access (TDMA) with four user channels on one radio carrier and 25 kHz spacing between carriers. Both point-to-point and point-to-multipoint transfer can be used. Digital data transmission is also included in the standard though at a low data rate. TETRA Mob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project 25
Project 25 (P25 or APCO-25) is a suite of standards for interoperable digital two-way radio products. P25 was developed by public safety professionals in North America and has gained acceptance for public safety, security, public service, and commercial applications worldwide. P25 radios are a direct replacement for analog UHF (typically FM) radios, but add the ability to transfer data as well as voice, allowing for more natural implementations of encryption and text messaging. P25 radios are commonly implemented by dispatch organizations, such as police, fire, ambulance and emergency rescue service, using vehicle-mounted radios combined with repeaters and handheld walkie-talkie use. Starting around 2012, products became available with the newer phase 2 modulation protocol, the older protocol known as P25 became P25 phase 1. P25 phase 2 products use the more advanced AMBE2+ vocoder, which allows audio to pass through a more compressed bitstream and provides two TDMA voice ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyco Electronics
TE Connectivity is an American Swiss-domiciled technology company that designs and manufactures connectors and sensors for several industries, such as automotive, industrial equipment, data communication systems, aerospace, defense, medical, oil and gas, consumer electronics and energy. TE Connectivity has a global workforce of 89,000 employees, including more than 8,000 engineers. The company serves customers in approximately 140 countries. History In 1941, Aircraft and Marine Products (AMP) was founded with solderless electrical connections for quick and removable wire connection used for aircraft and ships. After the war time boom the company had to adapt to post war economy and in 1956 the name was changed to AMP Incorporated when it incorporated. In 1999, Tyco International acquired American electronics connector manufacturer AMP Incorporated. In September 2002 the CEO ( L. Dennis Kozlowski) and CFO (Mark H. Swartz) of Tyco International Ltd. were indicted on charges i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is very widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like aircraft, ships, spacecraf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
