Base station (or base radio station) is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR)– a "land station in the land mobile service."
The International Telecommunication Union, originally the International Telegraph Union, is a specialized agency of the United Nations (UN) that is responsible for issues that concern information and communication technologies. It is the oldest among all the 15 specialised agencies of UN.
The ITU Radio Regulations regulates on law of nations scale radiocommunication services and the utilisation of radio frequencies. It is the supplementation to the Constitution and Convention of the International Telecommunication Union. In line to the ITU Constitution and Convention and the ITU International Telecommunication Regulations (ITR), this ITU Radio Regulations belong to the basic documents of the International Telecommunication Union. The ITU Radio Regulations comprise and regulate the part of the allocated electromagnetic spectrum from 9 kHz to 275 GHz.
Land station is – according to Article 1.69 of the International Telecommunication Union´s (ITU) ITU Radio Regulations (RR) – defined as «A radio station in the mobile service not intended to be used while in motion.»
The term is used in the context of mobile telephony, wireless computer networking and other wireless communications and in land surveying. In surveying, it is a GPS receiver at a known position, while in wireless communications it is a transceiver connecting a number of other devices to one another and/or to a wider area. In mobile telephony, it provides the connection between mobile phones and the wider telephone network. In a computer network, it is a transceiver acting as a switch for computers in the network, possibly connecting them to a/another local area network and/or the Internet. In traditional wireless communications, it can refer to the hub of a dispatch fleet such as a taxi or delivery fleet, the base of a TETRA network as used by government and emergency services or a CB shack.
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 terrestrial cellular network of base stations, whereas satellite phones connect to orbiting satellites. Both networks are interconnected to the public switched telephone network (PSTN) to allow any phone in the world to be dialed.
A transceiver is a device comprising both a transmitter and a receiver that are combined and share common circuitry or a single housing. When no circuitry is common between transmit and receive functions, the device is a transmitter-receiver. The term originated in the early 1920s. Similar devices include transponders, transverters, and repeaters.
A mobile phone, cell phone, cellphone, or hand phone, sometimes shortened to simply mobile, cell or just phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular network architecture, and, therefore, mobile telephones are called cellular telephones or cell phones, in North America. In addition to telephony, 2000s-era mobile phones support a variety of other services, such as text messaging, MMS, email, Internet access, short-range wireless communications, business applications, video games, and digital photography. Mobile phones offering only those capabilities are known as feature phones; mobile phones which offer greatly advanced computing capabilities are referred to as smartphones.
In the context of external land surveying, a base station is a GPS receiver at an accurately-known fixed location which is used to derive correction information for nearby portable GPS receivers. This correction data allows propagation and other effects to be corrected out of the position data obtained by the mobile stations, which gives greatly increased location precision and accuracy over the results obtained by uncorrected GPS receivers.
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for international shortwave broadcasters, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems.
In the area of wireless computer networking, a base station is a radio receiver/transmitter that serves as the hub of the local wireless network, and may also be the gateway between a wired network and the wireless network. It typically consists of a low-power transmitter and wireless router.
A wireless router is a device that performs the functions of a router and also includes the functions of a wireless access point. It is used to provide access to the Internet or a private computer network. Depending on the manufacturer and model, it can function in a wired local area network, in a wireless-only LAN, or in a mixed wired and wireless network.
In radio communications, a base station is a wireless communications station installed at a fixed location and used to communicate as part of one of the following:
A two-way radio is a radio that can both transmit and receive a signal, unlike a broadcast receiver which only receives content. It is an audio (sound) transceiver designed for bidirectional person-to-person voice communication with other users with similar radios using the same radio frequency (channel). Two-way radios are available in mobile, stationary base and hand-held portable configurations. Hand-held two-way radios are often called walkie-talkies, handie-talkies or hand-helds.
A radiotelephone is a communications system for transmission of speech over radio. Radiotelephone systems are very rarely interconnected with the public switched telephone network, and in some radio services, including GMRS, such interconnection is prohibited. "Radiotelephony" means transmission of sound (audio) by radio, in contrast to radiotelegraphy or video transmission. Where a two-way radio system is arranged for speaking and listening at a mobile station, and where it can be interconnected to the public switched telephone system, the system can provide mobile telephone service.
GSM is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile devices such as mobile phones and tablets. It was first deployed in Finland in December 1991. As of 2014, it has become the global standard for mobile communications – with over 90% market share, operating in over 193 countries and territories.
In professional two-way radio systems, a base station is used to maintain contact with a dispatch fleet of hand-held or mobile radios, and/or to activate one-way paging receivers. The base station is one end of a communications link. The other end is a movable vehicle-mounted radio or walkie-talkie.Examples of base station uses in two-way radio include the dispatch of tow trucks and taxicabs.
Dispatch is a procedure for assigning employees (workers) or vehicles to customers. Industries that dispatch include taxicabs, couriers, emergency services, as well as home and commercial services such as maid services, plumbing, HVAC, pest control and electricians.
Mobile radio or mobiles refer to wireless communications systems and devices which are based on radio frequencies(using commonly UHF or VHF frequencies), and where the path of communications is movable on either end. There are a variety of views about what constitutes mobile equipment. For US licensing purposes, mobiles may include hand-carried,, equipment. An obsolete term is radiophone.
A tow truck is a truck used to move disabled, improperly parked, impounded, or otherwise indisposed motor vehicles. This may involve recovering a vehicle damaged in an accident, returning one to a drivable surface in a mishap or inclement weather, or towing or transporting one via flatbed to a repair shop or other location.
Professional base station radios are often one channel. In lightly used base stations, a multi-channel unit may be employed.In heavily used systems, the capability for additional channels, where needed, is accomplished by installing an additional base station for each channel. Each base station appears as a single channel on the dispatch center control console. In a properly designed dispatch center with several staff members, this allows each dispatcher to communicate simultaneously, independently of one another, on a different channel as necessary. For example, a taxi company dispatch center may have one base station on a high-rise building in Boston and another on a different channel in Providence. Each taxi dispatcher could communicate with taxis in either Boston or Providence by selecting the respective base station on his or her console.
In dispatching centers it is common for eight or more radio base stations to be connected to a single dispatching console. Dispatching personnel can tell which channel a message is being received on by a combination of local protocol, unit identifiers, volume settings, and busy indicator lights. A typical console has two speakers identified as select and unselect. Audio from a primary selected channel is routed to the select speaker and to a headset. Each channel has a busy light which flashes when someone talks on the associated channel.
Base stations can be local controlled or remote controlled. Local controlled base stations are operated by front panel controls on the base station cabinet. Remote control base stations can be operated over tone- or DC-remote circuits. The dispatch point console and remote base station are connected by leased private line telephone circuits, (sometimes called RTO circuits), a DS-1, or radio links.The consoles multiplex transmit commands onto remote control circuits. Some system configurations require duplex, or four wire, audio paths from the base station to the console. Others require only a two-wire or half duplex link.
Interference could be defined as receiving any signal other than from a radio in your own system. To avoid interference from users on the same channel, or interference from nearby strong signals on another channel, professional base stations use a combination of:
Base stations are sometimes called control or fixed stations in US Federal Communications Commission licensing. These terms are defined in regulations inside Part 90 of the commissions regulations. In US licensing jargon, types of base stations include:
In amateur radio, a base station also communicates with mobile rigs but for hobby or family communications. Amateur systems sometimes serve as dispatch radio systems during disasters, search and rescue mobilizations, or other emergencies.
An Australian UHF CB base station is another example of part of a system used for hobby or family communications.
Wireless telephone differ from two-way radios in that:
A wireless telephone base station communicates with a mobile or hand-held phone. For example, in a wireless telephone system, the signals from one or more mobile telephones in an area are received at a nearby base station, which then connects the call to the land-line network. Other equipment is involved depending on the system architecture. Mobile telephone provider networks, such as European GSM networks, may involve carrier, microwave radio, and switching facilities to connect the call. In the case of a portable phone such as a US cordless phone, the connection is directly connected to a wired land line.
While low levels of radio-frequency power are usually considered to have negligible effects on health, national and local regulations restrict the design of base stations to limit exposure to electromagnetic fields. Technical measures to limit exposure include restricting the radio frequency power emitted by the station, elevating the antenna above ground level, changes to the antenna pattern, and barriers to foot or road traffic. For typical base stations, significant electromagnetic energy is only emitted at the antenna, not along the length of the antenna tower.
Because mobile phones and their base stations are two-way radios, they produce radio-frequency (RF) radiation in order to communicate, exposing people near them to RF radiation giving concerns about mobile phone radiation and health. Hand-held mobile telephones are relatively low power so the RF radiation exposures from them are generally low.
The World Health Organization has concluded that "there is no convincing scientific evidence that the weak RF signals from base stations and wireless networks cause adverse health effects."
The consensus of the scientific community is that the power from these mobile phone base station antennas is too low to produce health hazards as long as people are kept away from direct access to the antennas. However, current international exposure guidelines (ICNIRP) are based largely on the thermal effects of base station emissions, considering the non-thermal effects harmless.
Fuel cell backup power systems are added to critical base stations or cell sites to provide emergency power.
Communication problems and successes played an important role in the September 11, 2001, attacks and their aftermath. Systems were variously destroyed or overwhelmed by loads greater than they were designed to carry, or failed to operate as intended or desired.
A wireless network is a computer network that uses wireless data connections between network nodes.
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction.
Enhanced 911, E-911 or E911 is a system used in North America to automatically provide the caller's location to 911 dispatchers. 911 is the universal emergency telephone number in the region. In the European Union, a similar system exists known as E112 and known as eCall when called by a vehicle.
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter. Radio waves with frequencies above the UHF band fall into the super-high frequency (SHF) or microwave frequency range. Lower frequency signals fall into the VHF or lower bands. UHF radio waves propagate mainly by line of sight; they are blocked by hills and large buildings although the transmission through building walls is strong enough for indoor reception. They are used for television broadcasting, cell phones, satellite communication including GPS, personal radio services including Wi-Fi and Bluetooth, walkie-talkies, cordless phones, and numerous other applications.
A call box or callbox is a box containing a special-purpose direct line telephone or other telecommunications device, which has been used by various industries and institutions as a way for employees or clients at a remote location to contact a central dispatch office.
A cell site, cell tower, or cellular base station is a cellular-enabled mobile device site where antennae and electronic communications equipment are placed — typically on a radio mast, tower, or other raised structure — to create a cell in a cellular network. The raised structure typically supports antennae and one or more sets of transmitter/receivers transceivers, digital signal processors, control electronics, a GPS receiver for timing, primary and backup electrical power sources, and sheltering.
Professional mobile radio 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 3 to 20 miles depending on terrain. Output power is typically limited to 4 watts. Repeaters installed on tall buildings, hills or mountain peaks are used to increase the range of systems.
A cellular network or mobile network is a communication network where the last link is wireless. The network is distributed over land areas called cells, each served by at least one fixed-location transceiver, but more normally three cell sites or base transceiver stations. These base stations provide the cell with the network coverage which can be used for transmission of voice, data, and other types of content. A cell typically uses a different set of frequencies from neighboring cells, to avoid interference and provide guaranteed service quality within each cell.
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow for simultaneous communication in both directions between two connected parties or to provide a reverse path for the monitoring and remote adjustment of equipment in the field. There are two types of duplex communication systems: full-duplex (FDX) and half-duplex (HDX).
Diversity combining is the technique applied to combine the multiple received signals of a diversity reception device into a single improved signal.
An amateur radio repeater is an electronic device that receives a weak or low-level amateur radio signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. Many repeaters are located on hilltops or on tall buildings as the higher location increases their coverage area, sometimes referred to as the radio horizon, or "footprint". Amateur radio repeaters are similar in concept to those used by public safety entities, businesses, government, military, and more. Amateur radio repeaters may even use commercially packaged repeater systems that have been adjusted to operate within amateur radio frequency bands, but more often amateur repeaters are assembled from receivers, transmitters, controllers, power supplies, antennas, and other components, from various sources.
A radio repeater is a combination of a radio receiver and a radio transmitter that receives a signal and retransmits it, so that two-way radio signals can cover longer distances. A repeater sited at a high elevation can allow two mobile stations, otherwise out of line-of-sight propagation range of each other, to communicate. Repeaters are found in professional, commercial, and government mobile radio systems and also in amateur radio.
Remote controls are used any time a two-way radio base station is located away from the desk or office where communication originates. For example, a dispatch center for taxicabs may have an office downtown but have a base station on a distant mountain top. A Tone remote, also known as an EIA Tone remote, is a signaling system used to operate a two-way radio base station by some form of remote control.
Bridging Systems Interface is a standard protocol for communicating with physical interfaces which attach analog or digital voice radios to digital data networks—known as 'Radio over IP'--to make easier the use of remote radios by local users, and the sharing of radios by multiple users, in the service of improving emergency communications interoperability. The standard is promulgated by the SAFECOM program in the US Department of Homeland Security's Office for Interoperability and Compatibility, specifically, the VoIP Working Group.
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