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GSM-R Sharks Fin Mobile Antenna
GSM-R, Global System for Mobile Communications – Railway or GSM-Railway is an international wireless communications standard for railway communication and applications. A sub-system of European Rail Traffic Management System (ERTMS), it is used for communication between train and railway regulation control centers. The system is based on GSM and ''EIRENE – MORANE'' specifications which guarantee performance at speeds up to 500 km/h (310 mph), without any communication loss. GSM-R could be supplanted by LTE-R, with the first production implementation being in South Korea. However, LTE is generally considered to be a " 4G" protocol, and the UIC's Future Railway Mobile Communication System (FRMCS) program is considering moving to something " 5G"-based (specifically 3GPP R15/16), thus skipping two technological generations. History GSM-R is built on GSM technology, and benefits from the economies of scale of its GSM technology heritage, aiming at being a cost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wireless
Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most common wireless technologies use radio waves. With radio waves, intended distances can be short, such as a few meters for Bluetooth or as far as millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of applications of radio ''wireless technology'' include GPS units, garage door openers, wireless computer mouse, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones. Somewhat less common methods of achieving wireless communications involve other electromagnetic phenomena, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circuit Switching
Circuit switching is a method of implementing a telecommunications network in which two network nodes establish a dedicated communications channel ( circuit) through the network before the nodes may communicate. The circuit guarantees the full bandwidth of the channel and remains connected for the duration of the communication session. The circuit functions as if the nodes were physically connected as with an electrical circuit. Circuit switching originated in analog telephone networks where the network created a dedicated circuit between two telephones for the duration of a telephone call. It contrasts with message switching and packet switching used in modern digital networks in which the trunklines between switching centers carry data between many different nodes in the form of data packets without dedicated circuits. Description The defining example of a circuit-switched network is the early analog telephone network. When a call is made from one telephone to another, swit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classification Yard
A classification yard (American and Canadian English ( Canadian National Railway use)), marshalling yard (British, Hong Kong, Indian, Australian, and Canadian English ( Canadian Pacific Railway use)) or shunting yard (Central Europe) is a railway yard found at some freight train stations, used to separate railway cars onto one of several tracks. First the cars are taken to a track, sometimes called a ''lead'' or a ''drill''. From there the cars are sent through a series of switches called a ''ladder'' onto the classification tracks. Larger yards tend to put the lead on an artificially built hill called a ''hump'' to use the force of gravity to propel the cars through the ladder. Freight trains that consist of isolated cars must be made into trains and divided according to their destinations. Thus the cars must be shunted several times along their route in contrast to a unit train, which carries, for example, cars from the plant to a port, or coal from a mine to the power plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class 25 Gsmr Cab Radio
Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differently from such group phenomena as "types" or "kinds" * Class (set theory), a collection of sets that can be unambiguously defined by a property that all its members share * Hazard class, a dangerous goods classification * Social class, the hierarchical arrangement of individuals in society, usually defined by wealth and occupation * Working class, can be defined by rank, income or collar Arts, entertainment, and media * "The Class" (song), 1959 Chubby Checker song *Character class in role-playing games and other genres *Class 95 (radio station), a Singaporean radio channel Films * ''Class'' (film), 1983 American film * ''The Class'' (2007 film), 2007 Estonian film * ''The Class'' (2008 film), 2008 film (''Entre les murs'') Television * ''C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3GPP Long Term Evolution
In telecommunications, long-term evolution (LTE) is a standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA standards. It improves on those standards' capacity and speed by using a different radio interface and core network improvements. LTE is the upgrade path for carriers with both GSM/UMTS networks and CDMA2000 networks. Because LTE frequencies and bands differ from country to country, only multi-band phones can use LTE in all countries where it is supported. The standard is developed by the 3GPP (3rd Generation Partnership Project) and is specified in its Release 8 document series, with minor enhancements described in Release 9. LTE is also called 3.95G and has been marketed as "4G LTE" and "Advanced 4G"; but it does not meet the technical criteria of a 4G wireless service, as specified in the 3GPP Release 8 and 9 document series for LTE Advanced. The requirements were set forth by the ITU-R organisation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-division Multiple Access
Time-division multiple access (TDMA) is a channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This allows multiple stations to share the same transmission medium (e.g. radio frequency channel) while using only a part of its channel capacity. Dynamic TDMA is a TDMA variant that dynamically reserves a variable number of time slots in each frame to variable bit-rate data streams, based on the traffic demand of each data stream. TDMA is used in the digital 2G cellular systems such as Global System for Mobile Communications (GSM), IS-136, Personal Digital Cellular (PDC) and iDEN, and in the Digital Enhanced Cordless Telecommunications (DECT) standard for portable phones. TDMA was first used in satellite communication systems by Western Union in its Westar 3 communications satellite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum-shift Keying
In digital modulation, minimum-shift keying (MSK) is a type of continuous-phase frequency-shift keying that was developed in the late 1950s by Collins Radio employees Melvin L. Doelz and Earl T. Heald. Similar to OQPSK, MSK is encoded with bits alternating between quadrature components, with the Q component delayed by half the symbol period. However, instead of square pulses as OQPSK uses, MSK encodes each bit as a half sinusoid. This results in a constant-modulus signal (constant envelope signal), which reduces problems caused by non-linear distortion. In addition to being viewed as related to OQPSK, MSK can also be viewed as a continuous-phase frequency-shift keyed ( CPFSK) signal with a frequency separation of one-half the bit rate. In MSK the difference between the higher and lower frequency is identical to half the bit rate. Consequently, the waveforms used to represent a 0 and a 1 bit differ by exactly half a carrier period. Thus, the maximum frequency deviation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Railways
Indian Railways (IR) is a statutory body under the ownership of Ministry of Railways, Government of India that operates India's national railway system. It manages the fourth largest national railway system in the world by size, with a total route length of . or 83% of all the broad-gauge routes are electrified with 25 kV 50 Hz AC electric traction . In 2020, Indian Railways carried 808.6 crore (8.086 billion) passengers and in 2022, Railways transported 1418.1 million tonnes of freight. It runs 13,169 passenger trains daily, on both long-distance and suburban routes, covering 7,325 stations across India. Mail or Express trains, the most common types of trains, run at an average speed of . Suburban EMUs run at an average speed of . Ordinary passenger trains (incl. mixed) run at an average speed of . The maximum speed of passenger trains varies, with the Vande Bharat Express running at a peak speed of . In the freight segment, IR runs 8,479 trains daily. The a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trunked Radio System
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] |
European Conference Of Postal And Telecommunications Administrations
The European Conference of Postal and Telecommunications Administrations (CEPT) was established on June 26, 1959, by nineteen European states in Montreux, Switzerland, as a coordinating body for European state telecommunications and postal organizations. The acronym comes from the French version of its name ''Conférence européenne des administrations des postes et des télécommunications''. CEPT was responsible for the creation of the European Telecommunications Standards Institute (ETSI) in 1988. CEPT is organised into three main components: * Electronic Communications Committee (ECC) - responsible for radiocommunications and telecommunications matters and formed by the merger of ECTRA (European Committee for Telecommunications Regulatory Affairs) and ERC (European Radiocommunications Committee) in September 2001 **The permanent secretariat of the ECC is the European Communications Office (ECO) * European Committee for Postal Regulation (CERP, after the French ''"Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Range
A frequency band is an interval in the frequency domain, delimited by a lower frequency and an upper frequency. The term may refer to a radio band or an interval of some other spectrum. The frequency range of a system is the range over which it is considered to provide satisfactory performance, such as a useful level of signal with acceptable distortion characteristics. A listing of the upper and lower limits of frequency limits for a system is not useful without a criterion for what the range represents. Many systems are characterized by the range of frequencies to which they respond. Musical instruments produce different ranges of notes within the hearing range. The electromagnetic spectrum can be divided into many different ranges such as visible light, infrared or ultraviolet radiation, radio waves, X-rays and so on, and each of these ranges can in turn be divided into smaller ranges. A radio communications signal must occupy a range of frequencies carrying most of its ener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
