Base station (or base radio station) is – according to the
International Telecommunication Union's (ITU)
Radio Regulations (RR) – a "
land station
Land station (also: land radio station) is – according to ''Article 1.69'' of the International Telecommunication Union´s (ITU) ITU Radio Regulations (RR)ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.69, definitio ...
in the
land mobile service
Land mobile service (short: LMS) is – in line to ITU Radio Regulations – a mobile service between base stations and land mobile stations, or between land mobile stations.
In accordance with ''ITU Radio Regulations'' (article 1) variations of ...
."
The term is used in the context of
mobile telephony
Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Telephony is supposed to specifically point to a voice-only service or connection, though sometimes the li ...
,
wireless computer networking
A wireless network is a computer network that uses wireless data connections between network nodes.
Wireless networking is a method by which homes, telecommunications networks and business installations avoid the costly process of introducing c ...
and other
wireless communications and in
land surveying
Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is ca ...
. 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
computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...
s 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
A shack (or, in some areas, shanty) is a type of small shelter or dwelling, often primitive or rudimentary in design and construction.
Unlike huts, shacks are constructed by hand using available materials; however, whereas huts are usually ru ...
.
Land surveying
In the context of external land surveying, a base station is a
GPS
The Global Positioning System (GPS), originally Navstar GPS, is a Radionavigation-satellite service, satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of t ...
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.
Computer networking
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.
Wireless communications
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
push-to-talk two-way radio system, or;
* a
wireless telephone Wireless telephone may refer to:
* Cordless telephone, a telephone in which the handset is portable and communicates with the body of the phone by radio, instead of being attached by a cord
* Mobile phone, a portable telephone that can make and rec ...
system such as
cellular
Cellular may refer to:
*Cellular automaton, a model in discrete mathematics
* Cell biology, the evaluation of cells work and more
* ''Cellular'' (film), a 2004 movie
*Cellular frequencies, assigned to networks operating in cellular RF bands
*Cell ...
CDMA or
GSM cell site
A cell site, cell tower, or cellular base station is a cellular-enabled mobile device site where antennas and electronic communications equipment are placed (typically on a radio mast, tower, or other raised structure) to create a cell, or adjac ...
.
*
Terrestrial Trunked Radio
Base stations use
RF power amplifiers (
radio-frequency power amplifiers) to transmit and receive signals. The most common RF power amplifiers are
metal–oxide–semiconductor field-effect transistors (MOSFETs), particularly
LDMOS
LDMOS (laterally-diffused metal-oxide semiconductor) is a planar double-diffused MOSFET (metal–oxide–semiconductor field-effect transistor) used in amplifiers, including microwave power amplifiers, RF power amplifiers and audio power amplifie ...
(
power MOSFET
A power MOSFET is a specific type of metal–oxide–semiconductor field-effect transistor (MOSFET) designed to handle significant power levels. Compared to the other power semiconductor devices, such as an insulated-gate bipolar transistor (IG ...
) RF amplifiers.
RF LDMOS amplifiers replaced RF
bipolar transistor amplifiers in most base stations during the 1990s,
leading to the
wireless revolution.
Two-way radio
Professional
In professional two-way radio systems, a base station is used to maintain contact with a
dispatch fleet of
hand-held
A mobile device (or handheld computer) is a computer small enough to hold and operate in the hand. Mobile devices typically have a flat LCD or OLED screen, a touchscreen interface, and digital or physical buttons. They may also have a physical ...
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.
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
Providence often refers to:
* Providentia, the divine personification of foresight in ancient Roman religion
* Divine providence, divinely ordained events and outcomes in Christianity
* Providence, Rhode Island, the capital of Rhode Island in the ...
. 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 circuit''s), 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:
* minimum receiver specifications and filtering.
* analysis of other frequencies in use nearby.
* in the US, coordination of shared frequencies by coordinating agencies.
* locating equipment so that terrain blocks interfering signals.
* use of directional antennas to reduce unwanted signals.
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:
* A fixed station is a base station used in a system intended only to communicate with other base stations. A ''fixed'' station can also be radio link used to operate a distant base station by remote control. (No mobile or hand-held radios are involved in the system.)
* A control station is a base station used in a system with a repeater where the base station is used to communicate through the repeater.
* A temporary base is a base station used in one location for less than a year.
* A
repeater is a type of base station that extends the range of hand-held and mobile radios.
Amateur and hobbyist use
In
amateur radio
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communic ...
, 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
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
n
UHF CB base station is another example of part of a system used for hobby or family communications.
Wireless telephone
Wireless telephone Wireless telephone may refer to:
* Cordless telephone, a telephone in which the handset is portable and communicates with the body of the phone by radio, instead of being attached by a cord
* Mobile phone, a portable telephone that can make and rec ...
differ from two-way radios in that:
* wireless telephones are circuit switched: the communications paths are set up by dialing at the start of a call and the path remains in place until one of the callers hangs up.
* wireless telephones communicate with other telephones usually over the
public switched telephone network
The public switched telephone network (PSTN) provides Communications infrastructure, infrastructure and services for public Telecommunications, telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks 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
Carrier may refer to:
Entertainment
* ''Carrier'' (album), a 2013 album by The Dodos
* ''Carrier'' (board game), a South Pacific World War II board game
* ''Carrier'' (TV series), a ten-part documentary miniseries that aired on PBS in April 20 ...
,
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.
Emissions issues
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 field
An electromagnetic field (also EM field or EMF) is a classical (i.e. non-quantum) field produced by (stationary or moving) electric charges. It is the field described by classical electrodynamics (a classical field theory) and is the classical c ...
s. 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
Antenna ( antennas or antennae) may refer to:
Science and engineering
* Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves
* Antennae Galaxies, the name of two collid ...
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
In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) li ...
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, NOT considering the
''non-thermal'' effects harmless.
Emergency power
Fuel cell
A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most batteries in requ ...
backup power
An emergency power system is an independent source of electrical power that supports important electrical systems on loss of normal power supply. A standby power system may include a standby generator, batteries and other apparatus. Emergency p ...
systems are added to critical base stations or
cell site
A cell site, cell tower, or cellular base station is a cellular-enabled mobile device site where antennas and electronic communications equipment are placed (typically on a radio mast, tower, or other raised structure) to create a cell, or adjac ...
s to provide emergency power.
India telecoms to get fuel cell power
Media
Image:GaffneySC-CellTower.jpg, A cell tower near Thicketty, South Carolina
Thicketty (''also spelled Thickety'') is an unincorporated community in Cherokee County, South Carolina, United States. It lies between Gaffney and Cowpens along U.S. Route 29. Thicketty is located approximately northeast of Spartanburg
Sp ...
.
Image:BaseStationsBlorg.jpg, Two GSM mobile phone base station towers disguised as trees in Dublin, Ireland.
Image:PalmCellTower.jpg, A base station disguised as a palm tree in Tucson, Arizona.
Image:base station mexico-city.JPG, Close-up of a base station antenna in Mexico City, Mexico. There are three antennas: each serves a 120-degree segment of the horizon. The microwave dish links the site with the telephone network.
Image:iden.JPG, A professional rack-mount iDEN
Integrated Digital Enhanced Network (iDEN) is a mobile telecommunications technology, developed by Motorola, which provides its users the benefits of a trunked radio and a cellular telephone. It was called the first mobile social network by ma ...
Base Radio at a Cell Site.
Image:Trunked 5ch central control.svg, Trunked systems have groups of base stations configured as repeaters
''Repeaters'' is a 2010 Canadian thriller film directed by Carl Bessai, written by Arne Olsen, and starring Dustin Milligan, Amanda Crew, and Richard de Klerk as young drug addicts who find themselves stuck in a time loop.
Plot
Kyle, Sonia, and ...
. The center blocks with frequencies in this trunked block diagram each represent a base station.
File:136 to 174 MHz base station antennas.jpg, 136–174 MHz US professional base station antenna examples.
File:WiMAX equipment.jpg, WiMAX base station equipment with a sector antenna
A sector antenna is a type of directional microwave antenna with a sector-shaped radiation pattern. The word "sector" is used in the geometric sense; some portion of the circumference of a circle measured in degrees of arc. 60°, 90° and 120° ...
and wireless modem on top
File:Base station in Yekaterinburg.jpg, Cellular network base station in Yekaterinburg
See also
* Base transceiver station
* Mobile switching center
Network switching subsystem (NSS) (or GSM core network) is the component of a GSM system that carries out call out and mobility management functions for mobile phones roaming on the network of base stations. It is owned and deployed by mobi ...
* Macrocell
* Microcell
* Picocell
* Femtocell
* Access point base station
* Cell site
A cell site, cell tower, or cellular base station is a cellular-enabled mobile device site where antennas and electronic communications equipment are placed (typically on a radio mast, tower, or other raised structure) to create a cell, or adjac ...
* Cellular repeater
* Mobile phone
* Mobile phone radiation and health
* Portable phone
A cordless telephone or portable telephone has a portable telephone handset that connects by radio to a base station connected to the public telephone network. The operational range is limited, usually to the same building or within some short ...
* Signal strength
In telecommunications, particularly in radio frequency engineering, signal strength refers to the transmitter power output as received by a reference antenna at a distance from the transmitting antenna. High-powered transmissions, such as those us ...
* Audio level compression
* OpenBTS
* Bandstacked
The term bandstacked applies to an antenna or satellite feedhorn (LNBF) that is designed to operate on two or more bands of frequencies. Usually, a portion of the radio frequency spectrum that has been divided into a low band and a high band.
T ...
References
External links
Occupational Safety and Health Admin. Non-Ionizing Radiation Exposure Guidelines.
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{{DEFAULTSORT:Base Station
Surveying
Wireless networking
Telecommunications infrastructure
Radio stations and systems ITU