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GSM
The Global System for Mobile Communications (GSM) is a family of standards to describe the protocols for second-generation (2G) digital cellular networks, as used by mobile devices such as mobile phones and Mobile broadband modem, mobile broadband modems. GSM is also a trade mark owned by the GSM Association. "GSM (codec), GSM" may also refer to the voice codec initially used in GSM. 2G networks developed as a replacement for first generation (1G) analog cellular networks. The original GSM standard, which was developed by the European Telecommunications Standards Institute (ETSI), originally described a digital, circuit-switched network optimized for Duplex (telecommunications)#Full duplex, full duplex voice telephony, employing time division multiple access (TDMA) between stations. This expanded over time to include data communications, first by Circuit Switched Data, circuit-switched transport, then by Network packet, packet data transport via its upgraded standards, General Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSM Frequency Bands
GSM frequency bands or frequency ranges are the cellular frequencies designated by the International Telecommunication Union, ITU for the operation of GSM mobile phones and other mobile devices. Frequency bands GSM frequency usage around the world A dual-band 900/1800 device is required to be compatible with most networks apart from deployments in ITU Region 2. GSM-900, EGSM/EGSM-900 and GSM-1800 GSM-900 and GSM-1800 are used in most parts of the world (ITU-Regions 1 and 3): Africa, Europe, Middle East, Asia (apart from Japan and South Korea where GSM has never been introduced) and Oceania. In common GSM-900 is most widely used. Fewer operators use GSM-1800. Mobile phones on aircraft, Mobile Communication Services on Aircraft (MCA) uses GSM-1800. In some countries GSM-1800 is also referred to as "Digital Cellular System" (DCS). GSM-850 and GSM-1900 GSM-1900 and GSM-850 are used in most of North, South and Central America (ITU-Region 2). In North America, GSM operate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UMTS
The Universal Mobile Telecommunications System (UMTS) is a 3G mobile cellular system for networks based on the GSM standard. UMTS uses Wideband Code Division Multiple Access, wideband code-division multiple access (W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators compared to previous 2G systems like GPRS and Circuit Switched Data, CSD. UMTS on its provides a peak theoretical data rate of 2 Data-rate units, Mbit/s. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the International Telecommunication Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing IS-95, cdmaOne technology. The technology described in UMTS is sometimes also referred to as Freedom of Mobile Multimedia Access (FOMA) or 3GSM. UMTS specifies a complete network system, which includes the radio access network (UMTS Terrestrial Radio Access Network, or U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Packet Radio Service
General Packet Radio Service (GPRS), also called 2.5G, is a mobile data standard on the 2G cellular communication network's global system for mobile communications (GSM). Networks and mobile devices with GPRS started to roll out around the year 2001; it offered, for the first time on GSM networks, seamless data transmission using packet data for an "always-on" connection (eliminating the need to "dial-up"), so providing improved Internet access for web, email, WAP services, Multimedia Messaging Service (MMS) and others. Up until the rollout of GPRS, only circuit switched data was used in cellular networks, meaning that one or more radio channels were occupied for the entire duration of a data connection. On the other hand, on GPRS networks, data is broken into small packets and transmitted through available channels. This increased efficiency also gives it theoretical data rates of 56–114 kbit/s, significantly faster than the preceding Circuit Switched Data (CSD) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSM Association
The GSM Association (GSMA) is a non-profit trade association that represents the interests of mobile network operators worldwide. More than 750 mobile operators are full GSMA members and a further 400 companies in the broader mobile ecosystem are associate members. History The GSMA was formed in 1995 as the GSM MoU Association as a body to support and promote mobile operators using the GSM (Global System for Mobile communications) standard for cellular networks. It traces its history back to a memorandum of understanding signed in 1987 by 13 operators in 12 countries that committed to deploying GSM for mobile services. Membership and governance Full membership of the GSMA is open to licensed mobile operators using a GSM family technology. Approximately 750 such operators around the world are full GSMA members. Associate membership of the GSMA is open to non-operator companies active in the mobile ecosystem. These include handset and device makers, software companies, equi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSM (codec)
Full Rate (FR), also known as GSM-FR or GSM 06.10 (sometimes simply GSM), was the first digital speech coding standard used in the GSM digital mobile phone system. It uses linear predictive coding (LPC). The bit rate of the codec is 13 kbit/s, or 1.625 bits/audio sample (often padded out to 33 bytes/20 ms or 13.2 kbit/s). The quality of the coded speech is quite poor by modern standards, but at the time of development (early 1990s) it was a good compromise between computational complexity and quality, requiring only on the order of a million additions and multiplications per second. The codec is still widely used in networks around the world. Gradually FR will be replaced by Enhanced Full Rate (EFR) and Adaptive Multi-Rate (AMR) standards, which provide much higher speech quality with lower bit rate. Technology ''GSM-FR'' is specified in ETSI 06.10 (ETS 300 961) and is based on RPE-LTP ( Regular Pulse Excitation - Long Term Prediction) speech coding paradigm. Like m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circuit Switched Data
In communications, Circuit Switched Data (CSD) (also named GSM data) is the original form of data transmission developed for the time-division multiple access (TDMA)-based mobile phone systems like Global System for Mobile Communications (GSM). In later years, High Speed Circuit Switched Data (HSCSD) was developed providing increased data rates over conventional CSD. After 2010 many telecommunication carriers dropped support for CSD and HSCSD, having been superseded by GPRS and EDGE (E-GPRS). Technical CSD uses a single radio time slot to deliver 9.6 kbit/s data transmission to the GSM network switching subsystem where it could be connected through the equivalent of a normal modem to the Public Switched Telephone Network (PSTN), allowing direct calls to any dial-up service. For backwards compatibility, the IS-95 standard also supports CDMA Circuit Switched Data. However, unlike TDMA, there are no time slots, and all CDMA radios can be active all the time to deliver up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enhanced Data Rates For GSM Evolution
Enhanced Data rates for GSM Evolution (EDGE), also known as 2.75G and under various other names, is a 2G digital mobile phone technology for packet switched data transmission. It is a subset of General Packet Radio Service (GPRS) on the GSM network and improves upon it offering speeds close to 3G technology, hence the name 2.75G. EDGE is standardized by the 3GPP as part of the GSM family and as an upgrade to GPRS. EDGE was deployed on GSM networks beginning in 2003 – initially by Cingular (now AT&T) in the United States. It could be readily deployed on existing GSM and GPRS cellular equipment, making it an easier upgrade for cellular companies compared to the UMTS 3G technology that required significant changes. Through the introduction of sophisticated methods of coding and transmitting data, EDGE delivers higher bit-rates per radio channel, resulting in a threefold increase in capacity and performance compared with an ordinary GSM/GPRS connection - originally a max ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3GPP
The 3rd Generation Partnership Project (3GPP) is an umbrella term for a number of standards organizations which develop protocols for mobile telecommunications. Its best known work is the development and maintenance of: * GSM and related 2G and 2.5G standards, including GPRS and EDGE * UMTS and related 3G standards, including HSPA and HSPA+ * LTE and related 4G standards, including LTE Advanced and LTE Advanced Pro * 5G NR and related 5G standards, including 5G-Advanced * An evolved IP Multimedia Subsystem (IMS) developed in an access independent manner 3GPP is a consortium with seven national or regional telecommunication standards organizations as primary members ("organizational partners") and a variety of other organizations as associate members ("market representation partners"). The 3GPP organizes its work into three different streams: Radio Access Networks, Services and Systems Aspects, and Core Network and Terminals. The project was established in Decembe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellular Network
A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless network, wireless and the network is distributed over land areas called ''cells'', each served by at least one fixed-location transceiver (such as a base station). These base stations provide the cell with the network coverage which can be used for transmission of voice, data, and other types of content via radio waves. Each cell's coverage area is determined by factors such as the power of the transceiver, the terrain, and the frequency band being used. A cell typically uses a different set of frequencies from neighboring cells, to avoid interference and provide guaranteed service quality within each cell. When joined together, these cells provide radio coverage over a wide geographic area. This enables numerous Mobile device, devices, including mobile phones, Tablet computer, tablets, laptops equipped with mobile broadband modems, and Wearable technology, wea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philippe Dupuis (engineer)
Philippe Dupuis (; 1931-2019) was a French post-war telecommunications engineer, polytechnician, and a radiocommunications expert born in Saint Romain de Colbosc, Normandy, France. He co-invented Global System for Mobile Communications (GSM). He was on the ETSI Technical Committee and also served as the president of the GSM group. Early life and education Dupuis received a laureate in mathematics in the general competition of high schools and colleges in 1949. He graduated from Polytechnique in 1956. Career Dupuis started his career at PTT or "Postes, Télégraphes et Téléphones de France," in 1956. He supervised the launch of the first French mobile VHF telephony network covering Paris. Dupuis joined France Câbles & Radio, a state-owned company in 1962. The company sent him to Senegal for three years to oversee the activities in West Africa. In 1973, Dupuis led the creation of the Telecommunications Department for external networks. He re-joined PTT as the head of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobile Phones
A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This radio frequency link connects to the switching systems of a mobile phone operator, providing access to the public switched telephone network (PSTN). Modern mobile telephony relies on a cellular network architecture, which is why mobile phones are often referred to as 'cell phones' in North America. Beyond traditional voice communication, digital mobile phones have evolved to support a wide range of additional services. These include text messaging, multimedia messaging, email, and internet access (via LTE, 5G NR or Wi-Fi), as well as short-range wireless technologies like Bluetooth, infrared, and ultra-wideband (UWB). Mobile phones also support a variety of multimedia capabilities, such as digital photography, video recording, and gaming ... [...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 digital 2G cellular systems such as Global System for Mobile Communications (GSM), IS-136, Personal Digital Cellular (PDC) and iDEN, in the Maritime Automatic Identification System, and in the Digital Enhanced Cordless Telecommunications (DECT) standard for portable phones. TDMA was first used in satellite communication systems by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
