1.
Telecommunication
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Telecommunication is the transmission of signs, signals, messages, writings, images and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic systems. Telecommunication occurs when the exchange of information between communication participants includes the use of technology and it is transmitted either electrically over physical media, such as cables, or via electromagnetic radiation. Such transmission paths are divided into communication channels which afford the advantages of multiplexing. The term is used in its plural form, telecommunications. Early means of communicating over a distance included visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, other examples of pre-modern long-distance communication included audio messages such as coded drumbeats, lung-blown horns, and loud whistles. Zworykin, John Logie Baird and Philo Farnsworth, the word telecommunication is a compound of the Greek prefix tele, meaning distant, far off, or afar, and the Latin communicare, meaning to share. Its modern use is adapted from the French, because its use was recorded in 1904 by the French engineer. Communication was first used as an English word in the late 14th century, in the Middle Ages, chains of beacons were commonly used on hilltops as a means of relaying a signal. Beacon chains suffered the drawback that they could pass a single bit of information. One notable instance of their use was during the Spanish Armada, in 1792, Claude Chappe, a French engineer, built the first fixed visual telegraphy system between Lille and Paris. However semaphore suffered from the need for skilled operators and expensive towers at intervals of ten to thirty kilometres, as a result of competition from the electrical telegraph, the last commercial line was abandoned in 1880. Homing pigeons have occasionally used throughout history by different cultures. Pigeon post is thought to have Persians roots and was used by the Romans to aid their military, frontinus said that Julius Caesar used pigeons as messengers in his conquest of Gaul. The Greeks also conveyed the names of the victors at the Olympic Games to various cities using homing pigeons, in the early 19th century, the Dutch government used the system in Java and Sumatra. And in 1849, Paul Julius Reuter started a service to fly stock prices between Aachen and Brussels, a service that operated for a year until the gap in the telegraph link was closed. Sir Charles Wheatstone and Sir William Fothergill Cooke invented the telegraph in 1837. Also, the first commercial electrical telegraph is purported to have constructed by Wheatstone and Cooke. Both inventors viewed their device as an improvement to the electromagnetic telegraph not as a new device, samuel Morse independently developed a version of the electrical telegraph that he unsuccessfully demonstrated on 2 September 1837
2.
Mobile telephony
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Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Mobile phones connect to a cellular network of base stations. Both networks are interconnected to the switched telephone network to allow any phone in the world to be dialed. In 2010 there were estimated to be five billion mobile cellular subscriptions in the world. S, public mobile phone systems were first introduced in the years after the Second World War and made use of technology developed before and during the conflict. The first system opened in St Louis, Missouri, USA in 1946 whilst other countries followed in the succeeding decades, the UK introduced its System 1 manual radiotelephone service as the South Lancashire Radiophone Service in 1958. Calls were made via an operator using handsets identical to ordinary phone handsets, the phone itself was a large box located in the boot of the vehicle containing valves and other early electronic components. Although an uprated manual service was extended to cover most of the UK and these cellular systems were based on US Advanced Mobile Phone Service technology, the modified technology being named Total Access Communication System. In 1947 Bell Labs was the first to propose a cellular telephone network. In 1956 the MTA system was launched in Sweden, both problems were solved by Bell Labs employee Amos Joel who, in 1970 applied for a patent for a mobile communications system. However, a consulting firm calculated the entire U. S. As a consequence, Bell Labs concluded that the invention was of little or no consequence, the invention earned Joel induction into the National Inventors Hall of Fame in 2008. The first call on a mobile phone was made on April 3,1973 by Martin Cooper. Bell Labs went on to install the first trial cellular network in Chicago in 1978. This trial system was licensed by the FCC to ATT for commercial use in 1982 and, as part of the arrangements for the breakup of ATT. The first commercial system opened in Chicago in October 1983, a system designed by Motorola also operated in the Washington D. C. /Baltimore area from summer 1982 and became a full public service later the following year. Japans first commercial service was launched by NTT in 1978. The first fully automatic first generation system was the Nordic Mobile Telephone system, simultaneously launched in 1981 in Denmark, Finland, Norway. NMT was the first mobile phone network featuring international roaming, the Swedish electrical engineer Östen Mäkitalo started to work on this vision in 1966, and is considered as the father of the NMT system and some consider him also the father of the cellular phone
3.
Enhanced Data Rates for GSM Evolution
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Enhanced Data rates for GSM Evolution is a digital mobile phone technology that allows improved data transmission rates as a backward-compatible extension of GSM. EDGE is considered a pre-3G radio technology and is part of ITUs 3G definition, EDGE was deployed on GSM networks beginning in 2003 – initially by Cingular in the United States. EDGE is standardized also by 3GPP as part of the GSM family, a variant, so called Compact-EDGE, was developed for use in a portion of Digital AMPS network spectrum. EDGE can be used for any packet switched application, such as an Internet connection, Evolved EDGE continues in Release 7 of the 3GPP standard providing reduced latency and more than doubled performance e. g. to complement High-Speed Packet Access. Peak bit-rates of up to 1 Mbit/s and typical bit-rates of 400 kbit/s can be expected, eDGE/EGPRS is implemented as a bolt-on enhancement for 2. 5G GSM/GPRS networks, making it easier for existing GSM carriers to upgrade to it. EDGE is a superset to GPRS and can function on any network with GPRS deployed on it, EDGE requires no hardware or software changes to be made in GSM core networks. EDGE-compatible transceiver units must be installed and the base station needs to be upgraded to support EDGE. If the operator already has this in place, which is often the case today, today EDGE is supported by all major chip vendors for both GSM and WCDMA/HSPA. In addition to Gaussian minimum-shift keying, EDGE uses higher-order PSK/8 phase shift keying for the five of its nine modulation. EDGE produces a 3-bit word for every change in carrier phase and this effectively triples the gross data rate offered by GSM. It introduces a new technology not found in GPRS, Incremental Redundancy and this increases the probability of correct decoding. EDGE can carry a bandwidth up to 236 kbit/s for 4 timeslots in packet mode and this means it can handle four times as much traffic as standard GPRS. EDGE meets the International Telecommunications Unions requirement for a 3G network and it also enhances the circuit data mode called HSCSD, increasing the data rate of this service. In GPRS, the Coding Schemes CS-1 to CS-4 specify the number of parity bits generated by the cyclic code, in GPRS Coding Schemes CS-1 through CS-3, the convolutional code is of rate 1/2, i. e. each input bit is converted into two coded bits. In Coding Schemes CS-2 and CS-3, the output of the code is punctured to achieve the desired code rate. In GPRS Coding Scheme CS-4, no coding is applied. In EGPRS/EDGE, the Modulation and Coding Schemes MCS-1 to MCS-9 take the place of the Coding Schemes of GPRS, MCS-1 through MCS-4 use GMSK and have performance similar to GPRS, while MCS-5 through MCS-9 use 8PSK. In all EGPRS Modulation and Coding Schemes, a code of rate 1/3 is used
4.
GSM
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As of 2014 it has become the de facto global standard for mobile communications – with over 90% market share, operating in over 219 countries and territories. This expanded over time to include communications, first by circuit-switched transport, then by packet data transport via GPRS. Subsequently, the 3GPP developed third-generation UMTS standards followed by fourth-generation LTE Advanced standards, GSM is a trademark owned by the GSM Association. It may also refer to the most common voice codec used, the decision to develop a continental standard eventually resulted in a unified, open, standard-based network which was larger than that in the United States. In February 1987 Europe produced the very first agreed GSM Technical Specification, the MoU drew-in mobile operators from across Europe to pledge to invest in new GSM networks to an ambitious common date. In 1989, the Groupe Spécial Mobile committee was transferred from CEPT to the European Telecommunications Standards Institute, in parallel, France and Germany signed a joint development agreement in 1984 and were joined by Italy and the UK in 1986. In 1986 the European Commission proposed reserving the 900 MHz spectrum band for GSM, the former Finnish prime minister Harri Holkeri made the worlds first GSM call on July 1,1991, calling Kaarina Suonio using a network built by Telenokia and Siemens and operated by Radiolinja. In the following year,1992, saw the sending of the first short messaging service message, work began in 1991 to expand the GSM standard to the 1800 MHz frequency band and the first 1800 MHz network became operational in the UK by 1993 called and DCS1800. Also that year, Telecom Australia became the first network operator to deploy a GSM network outside Europe and the first practical hand-held GSM mobile phone became available. In 1995, fax, data and SMS messaging services were launched commercially, in the same year, the GSM Association formed. Pre-paid GSM SIM cards were launched in 1996 and worldwide GSM subscribers passed 100 million in 1998, in 2000 the first commercial GPRS services were launched and the first GPRS-compatible handsets became available for sale. In 2001 the first UMTS network was launched, a 3G technology that is not part of GSM, worldwide GSM subscribers exceeded 500 million. In 2002 the first Multimedia Messaging Service were introduced and the first GSM network in the 800 MHz frequency band became operational, EDGE services first became operational in a network in 2003 and the number of worldwide GSM subscribers exceeded 1 billion in 2004. By 2005, GSM networks accounted for more than 75% of the cellular network market. In 2005 the first HSDPA-capable network also became operational, the first HSUPA network launched in 2007. Worldwide GSM subscribers exceeded three billion in 2008, GSM is a second-generation standard employing time-division multiple-Access spectrum-sharing, issued by the European Telecommunications Standards Institute. GSM, for the first time, set a standard for Europe for wireless networks. It was also adopted by many countries outside Europe and this allowed subscribers to use other GSM networks that have roaming agreements with each other
5.
General Packet Radio Service
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General Packet Radio Service is a packet oriented mobile data service on the 2G and 3G cellular communication systems global system for mobile communications. GPRS was originally standardized by European Telecommunications Standards Institute in response to the earlier CDPD and it is now maintained by the 3rd Generation Partnership Project. GPRS usage is typically charged based on volume of data transferred, contrasting with circuit switched data, sometimes billing time is broken down to every third of a minute. Usage above the cap is charged per megabyte, speed limited. In 2G systems, GPRS provides data rates of 56–114 kbit/second, 2G cellular technology combined with GPRS is sometimes described as 2. 5G, that is, a technology between the second and third generations of mobile telephony. It provides moderate-speed data transfer, by using unused time division multiple access channels in, for example, GPRS is integrated into GSM Release 97 and newer releases. The GPRS core network allows 2G, 3G and WCDMA mobile networks to transmit IP packets to external networks such as the Internet, the GPRS system is an integrated part of the GSM network switching subsystem. This is much faster using the ordinary SMS over GSM. GPRS supports the protocols, Internet Protocol. In practice, built-in mobile browsers use IPv4 since IPv6 was not yet popular, in this mode PPP is often not supported by the mobile phone operator but if the mobile is used as a modem to the connected computer, PPP is used to tunnel IP to the phone. This allows an IP address to be assigned dynamically to the mobile equipment and this is typically used for applications like wireless payment terminals, although it has been removed from the standard. When TCP/IP is used, each phone can have one or more IP addresses allocated, GPRS will store and forward the IP packets to the phone even during handover. The TCP handles any packet loss, devices supporting GPRS are divided into three classes, Class A Can be connected to GPRS service and GSM service, using both at the same time. Such devices are known to be available today, Class B Can be connected to GPRS service and GSM service, but using only one or the other at a given time. During GSM service, GPRS service is suspended, and then resumed automatically after the GSM service has concluded, most GPRS mobile devices are Class B. Class C Are connected to either GPRS service or GSM service, must be switched manually between one or the other service. A true Class A device may be required to transmit on two different frequencies at the time, and thus will need two radios. To get around this requirement, a GPRS mobile may implement the dual transfer mode feature
6.
UMTS
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The Universal Mobile Telecommunications System is a third generation mobile cellular system for networks based on the GSM standard. UMTS uses wideband code division multiple access radio access technology to offer greater spectral efficiency, UMTS specifies a complete network system, which includes the radio access network, the core network and the authentication of users via SIM cards. The technology described in UMTS is sometimes referred to as Freedom of Mobile Multimedia Access or 3GSM. Unlike EDGE and CDMA2000, UMTS requires new base stations and new frequency allocations, UMTS supports maximum theoretical data transfer rates of 42 Mbit/s when Evolved HSPA is implemented in the network. Users in deployed networks can expect a transfer rate of up to 384 kbit/s for Release 99 handsets, since 2006, UMTS networks in many countries have been or are in the process of being upgraded with High-Speed Downlink Packet Access, sometimes known as 3. 5G. Currently, HSDPA enables downlink transfer speeds of up to 21 Mbit/s, work is also progressing on improving the uplink transfer speed with the High-Speed Uplink Packet Access. The first national consumer UMTS networks launched in 2002 with a emphasis on telco-provided mobile applications such as mobile TV. UMTS combines three different terrestrial air interfaces, GSMs Mobile Application Part core, and the GSM family of speech codecs, the air interfaces are called UMTS Terrestrial Radio Access. All air interface options are part of ITUs IMT-2000, in the currently most popular variant for cellular mobile telephones, W-CDMA is used. Please note that the terms W-CDMA, TD-CDMA and TD-SCDMA are misleading, while they suggest covering just a channel access method, they are actually the common names for the whole air interface standards. W-CDMA or WCDMA, along with UMTS-FDD, UTRA-FDD, or IMT-2000 CDMA Direct Spread is an air interface found in 3G mobile telecommunications networks. W-CDMA uses the DS-CDMA channel access method with a pair of 5 MHz wide channels, in contrast, the competing CDMA2000 system uses one or more available 1.25 MHz channels for each direction of communication. W-CDMA systems are criticized for their large spectrum usage, which delayed deployment in countries that acted relatively slowly in allocating new frequencies specifically for 3G services. The specific frequency bands originally defined by the UMTS standard are 1885–2025 MHz for the mobile-to-base, in the US, 1710–1755 MHz and 2110–2155 MHz are used instead, as the 1900 MHz band was already used. Some carriers such as T-Mobile use band numbers to identify the UMTS frequencies, in the late 1990s, W-CDMA was developed by NTT DoCoMo as the air interface for their 3G network FOMA. Later NTT DoCoMo submitted the specification to the International Telecommunication Union as a candidate for the international 3G standard known as IMT-2000. The ITU eventually accepted W-CDMA as part of the IMT-2000 family of 3G standards, as an alternative to CDMA2000, EDGE, later, W-CDMA was selected as an air interface for UMTS. As NTT DoCoMo did not wait for the finalisation of the 3G Release 99 specification, however, this has been resolved by NTT DoCoMo updating their network
7.
High Speed Packet Access
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A further improved 3GPP standard, Evolved High Speed Packet Access, was released late in 2008 with subsequent worldwide adoption beginning in 2010. The newer standard allows bit-rates to reach as high as 337 Mbit/s in the downlink and 34 Mbit/s in the uplink, however, these speeds are rarely achieved in practice. The first HSPA specifications supported increased peak data rates of up to 14 Mbit/s in the downlink and 5.76 Mbit/s in the uplink. It also reduced latency and provided up to five times more capacity in the downlink. HSDPA has been introduced with 3GPP Release 5, which accompanies a improvement on the uplink providing a new bearer of 384 kbit/s. The previous maximum bearer was 128 kbit/s, as well as improving data rates, HSDPA also decreases latency and so the round trip time for applications. HSPA+ introduced in 3GPP Release 7 further increases data rates by adding 64QAM modulation, MIMO and Dual-Cell HSDPA operation, even higher speeds of up to 337.5 Mbit/s are possible with Release 11 of the 3GPP standards. The first phase of HSDPA has been specified in the 3GPP release 5, phase one introduces new basic functions and is aimed to achieve peak data rates of 14.0 Mbit/s with significantly reduced latency. The improvement in speed and latency reduces the cost per bit, further new features are the High Speed Downlink Shared Channels, the adaptive modulation QPSK and 16QAM and the High Speed Medium Access protocol in base station. The upgrade to HSDPA is often just an update for WCDMA networks. In general voice calls are prioritized over data transfer. The following table is derived from table 5. 1a of the release 11 of 3GPP TS25.306 and shows maximum data rates of different device classes and by what combination of features they are achieved. The per-cell per-stream data rate is limited by the Maximum number of bits of an HS-DSCH transport block received within an HS-DSCH TTI, so for example Cat 10 can decode 27952 bits/2 ms =13.976 MBit/s. Categories 1-4 and 11 have inter-TTI intervals of 2 or 3, Dual-Cell and MIMO 2x2 each multiply the maximum data rate by 2, because multiple independent transport blocks are transmitted over different carriers or spatial streams, respectively. The data rates given in the table are rounded to one decimal point, further UE categories were defined from 3GGP Release 7 onwards as Evolved HSPA and are listed in Evolved HSDPA UE Categories. Notes, As of 28 August 2009,250 HSDPA networks have commercially launched mobile services in 109 countries. 169 HSDPA networks support 3.6 Mbit/s peak downlink data throughput, a growing number are delivering 21 Mbit/s peak data downlink and 28 Mbit/s. CDMA2000-EVDO networks had the lead on performance, and Japanese providers were highly successful benchmarks for it
