Cellular network

A cellular network or mobile network (sometimes known as cellular communication network or mobile communication network) is a telecommunications network where the link to and from end nodes is 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, these cells provide radio coverage over a wide geographic area. This enables numerous devices, such as mobile phones, tablets, laptops equipped with mobile broadband modems, and wearable devices such as smartwatches, to communicate with each other and with fixed transceivers and telephones anywhere in the network, via base stations, even if some of the devices are moving through more than one cell during transmission. The design of cellular networks allows for seamless handover, enabling uninterrupted communication when a device moves from one cell to another.…

A cellular network or mobile network (sometimes known as cellular communication network or mobile communication network) is a telecommunications network where the link to and from end nodes is 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, these cells provide radio coverage over a wide geographic area. This enables numerous devices, such as mobile phones, tablets, laptops equipped with mobile broadband modems, and wearable devices such as smartwatches, to communicate with each other and with fixed transceivers and telephones anywhere in the network, via base stations, even if some of the devices are moving through more than one cell during transmission. The design of cellular networks allows for seamless handover, enabling uninterrupted communication when a device moves from one cell to another. Modern cellular networks utilize advanced technologies such as Multiple Input Multiple Output (MIMO), beamforming, and small cells to enhance network capacity and efficiency. Cellular networks can offer a number of desirable features: More capacity than a single large transmitter, since the same frequency can be used for multiple links as long as they are in different cells Mobile devices use less power than a single transmitter or satellite since the cell towers are closer Larger coverage area than a single terrestrial transmitter, since additional cell towers can be added indefinitely and are not limited by the horizon Capability of utilizing higher frequency signals (and thus more available bandwidth / faster data rates) that are not able to propagate at long distances With data compression and multiplexing, several video (including digital video) and audio channels may travel through a higher frequency signal on a single wideband carrier Major telecommunications providers have deployed voice and data cellular networks over most of the inhabited land area of Earth. This allows mobile phones and other devices to be connected to the public switched telephone network and public Internet access. In addition to traditional voice and data services, cellular networks now support internet of things (IoT) applications, connecting devices such as smart meters, vehicles, and industrial sensors. The evolution of cellular networks from 1G to 5G has progressively introduced faster speeds, lower latency, and support for a larger number of devices, enabling advanced applications in fields such as healthcare, transportation, and smart cities. Private cellular networks can be used for research or for large organizations and fleets, such as dispatch for local public safety agencies or a taxicab company, as well as for local wireless communications in enterprise and industrial settings such as factories, warehouses, mines, power plants, substations, oil and gas facilities and ports. In September 1981, Jan Stenbeck, a financier and businessman, launched Comvik, a Swedish telecommunications company. Comvik was the first European telecommunications firm to challenge the state's telephone monopoly on the industry. According to sources, Comvik was the first to launch a commercial automatic cellular system before Televerket launched its own in October 1981. However, at the time of the new network's release, the Swedish Post and Telecom Authority threatened to shut down the system after claiming that the company had used an unlicensed automatic gear that could interfere with its own networks. In December 1981, Sweden awarded Comvik with a license to operate its own automatic cellular network in the spirit of market competition. The Bell System had developed cellular technology since 1947, and had cellular networks in operation in Chicago, Illinois, and Dallas, Texas, prior to 1979; however, regulatory battles delayed AT&T's deployment of cellular service to 1983, when its Regional Holding Company Illinois Bell first provided cellular service. First-generation cellular network technology continued to expand its reach to the rest of the world. In 1990, Millicom Inc., a telecommunications service provider, strategically partnered with Comvik's international cellular operations to become Millicom International Cellular SA. The company went on to establish a 1G systems foothold in Ghana, Africa under the brand name Mobitel. In 2006, the company's Ghana operations were renamed to Tigo. The wireless revolution began in the early 1990s, leading to the transition from analog to digital networks. The MOSFET invented at Bell Labs between 1955 and 1960, was adapted for cellular networks by the early 1990s, with the wide adoption of power MOSFET, LDMOS (RF amplifier), and RF CMOS (RF circuit) devices leading to the development and proliferation of digital wireless mobile networks. The first commercial digital cellular network, the 2G generation, was launched in 1991. This sparked competition in the sector as the new operators challenged the incumbent 1G analog network operators. D=R\sqrt{3N} , where R is the cell radius and N is the number of cells per cluster. Cells may vary in radius from . The boundaries of the cells can also overlap between adjacent cells and large cells can be divided into smaller cells. The frequency reuse factor is the rate at which the same frequency can be used in the network. It is 1/K (or K according to some books) where K is the number of cells which cannot use the same frequencies for transmission. Common values for the frequency reuse factor are 1/3, 1/4, 1/7, 1/9 and 1/12 (or 3, 4, 7, 9 and 12, depending on notation). In case of N sector antennas on the same base station site, each with different direction, the base station site can serve N different sectors. N is typically 3. A reuse pattern of N/K denotes a further division in frequency among N sector antennas per site. Some current and historical reuse patterns are 3/7 (North American AMPS), 6/4 (Motorola NAMPS), and 3/4 (GSM). If the total available bandwidth is B, each cell can only use a number of frequency channels corresponding to a bandwidth of B/K, and each sector can use a bandwidth of B/NK. Code-division multiple access-based systems use a wider frequency band to achieve the same rate of transmission as FDMA, but this is compensated for by the ability to use a frequency reuse factor of 1, for example using a reuse pattern of 1/1. In other words, adjacent base station sites use the same frequencies, and the different base stations and users are separated by codes rather than frequencies. While N is shown as 1 in this example, that does not mean the CDMA cell has only one sector, but rather that the entire cell bandwidth is also available to each sector individually. Recently also orthogonal frequency-division multiple access based systems such as LTE are being deployed with a frequency reuse of 1. Since such systems do not spread the signal across the frequency band, inter-cell radio resource management is important to coordinate resource allocation between different cell sites and to limit the inter-cell interference. There are various means of inter-cell interference coordination (ICIC) already defined in the standard. Coordinated scheduling, multi-site MIMO or multi-site beamforming are other examples for inter-cell radio resource management that might be standardized in the future. ==See also== Lists and technical information: Mobile technologies 2G networks (the first digital networks, 1G and 0G were analog): GSM Circuit Switched Data (CSD) GPRS EDGE(IMT-SC) Evolved EDGE Digital AMPS Cellular Digital Packet Data (CDPD) cdmaOne (IS-95) Circuit Switched Data (CSD) Personal Handy-phone System (PHS) Personal Digital Cellular 3G networks: UMTS W-CDMA (air interface) TD-CDMA (air interface) TD-SCDMA (air interface) HSPA HSDPA HSPA+ CDMA2000 OFDMA (air interface) EVDO SVDO 4G networks: IMT Advanced LTE (TD-LTE) LTE Advanced LTE Advanced Pro WiMAX WiMAX-Advanced (WirelessMAN-Advanced) Ultra Mobile Broadband (never commercialized) MBWA (IEEE 802.20, Mobile Broadband Wireless Access, HC-SDMA, iBurst, has been shut down) 5G networks: 5G NR 5G-Advanced Starting with EVDO the following techniques can also be used to improve performance: MIMO, SDMA and Beamforming Cellular frequencies CDMA frequency bands GSM frequency bands UMTS frequency bands LTE frequency bands 5G NR frequency bands Deployed networks by technology List of UMTS networks List of CDMA2000 networks List of LTE networks List of deployed WiMAX networks List of 5G NR networks Deployed networks by country (including technology and frequencies) List of mobile network operators of Europe List of mobile network operators of the Americas List of mobile network operators of the Asia Pacific region List of mobile network operators of the Middle East and Africa List of mobile network operators (summary) Mobile country code - code, frequency, and technology for each operator in each country Comparison of mobile phone standards List of mobile phone brands by country (manufacturers) Equipment: Cellular repeater Cellular router Professional mobile radio (PMR) OpenBTS Remote radio head Baseband unit Radio access network Mobile cell sites Other: Antenna diversity Cellular traffic MIMO (multiple-input and multiple-output) Mobile edge computing Mobile phone radiation and health Network simulation Personal Communications Service Radio resource management (RRM) Routing in cellular networks Signal strength Title 47 of the Code of Federal Regulations William C. Y. Lee, Mobile Cellular Telecommunications Systems (1989), McGraw-Hill. .

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