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Voice Group Call Service
The voice group call service (VGCS) is a mobile communication service for GSM, that allows subscribers to communicate to multiple other subscribers at the same time. For this special mobiles are required that support this function. A first deployment was seen with European Railways. This service is a feature of ASCI (Advanced Speech Call Items) in GSM. Description This service allows speech conversation of a predefined group of service subscribers in half duplex mode on the radio link taking into account multiple mobile service subscribers involved in the VGCS call per cell. The VGCS is applicable to all mobile stations in a certain network and area which have the technical capability and the corresponding subscription, respectively, to participate in a VGCS call. Background The first commercial use was for Railways. For GSM-Railway this is one of the most important features. VGCS is important to compete with TETRA for Professional Mobile Radio (PMR). This service is location de ... [...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] |
Professional Mobile Radio
Professional mobile radio (also known as private mobile radio (PMR) in the UK) are person-to-person two-way radio voice communications systems which use portable, mobile, base station, and dispatch console radios. PMR radio systems are based on such standards as MPT-1327, TETRA, APCO 25, and DMR which are designed for dedicated use by specific organizations, or standards such as NXDN intended for general commercial use. These systems are used by police, fire, ambulance, and emergency services, and by commercial firms such as taxis and delivery services. Most systems are half-duplex, in which multiple radios share a common radio channel, and only one can transmit at a time. Transceivers are normally in receive mode, the user presses a push-to-talk button on his microphone when he wants to talk, which turns on his transmitter and turns off his receiver. They use channels in the VHF and UHF bands, giving them a limited range, usually depending on terrain. Output power is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSM-R
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] |
