A cleverly mounted base station on top of an Electricity pylon.

A base station disguised as a palm tree in Tucson, Arizona

A cell site is a site where antennas and electronic communications equipment are placed to create a cell in a cellular network for the use of mobile phones. A cell site is composed of a tower or other elevated structure for mounting antennas, and one or more sets of transmitter/receivers transceivers, digital signal processors, control electronics, a GPS receiver for timing (for CDMA2000 or IS-95 systems), regular and backup electrical power sources, and sheltering. Image File history File links Size of this preview: 400 × 600 pixelsFull resolution (1536 × 2304 pixel, file size: 1. ... Image File history File links Size of this preview: 400 × 600 pixelsFull resolution (1536 × 2304 pixel, file size: 1. ... A pylon is a tall steel lattice structure used to support overhead electricity conductors for power transmission. ... Image File history File linksMetadata Size of this preview: 418 × 599 pixel Image in higher resolution (766 × 1098 pixel, file size: 545 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Base station Cell... Image File history File linksMetadata Size of this preview: 418 × 599 pixel Image in higher resolution (766 × 1098 pixel, file size: 545 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Base station Cell... Genera Many; see list of Arecaceae genera Arecaceae (also known as Palmae or Palmaceae), the palm family, is a family of flowering plants, belonging to the monocot order Arecales. ... Nickname: The Old Pueblo Location in Pima County and the state of Arizona Coordinates: Country United States State Arizona Counties Pima Mayor Bob Walkup (R) Area    - City 505. ... Official language(s) English Capital Phoenix Largest city Phoenix Area  Ranked 6th  - Total 113,998 sq mi (295,254 km²)  - Width 310 miles (500 km)  - Length 400 miles (645 km)  - % water 0. ... A cellular network is a radio network made up of a number of radio cells (or just cells) each served by a fixed transmitter, normally known as a cell site or base station. ... A yagi antenna Most simply, an antenna is an electronic component designed to send or receive radio waves. ... A transceiver is a device that has both a transmitter and a receiver which are combined in to one. ... A digital signal processor (DSP) is a specialized microprocessor designed specifically for digital signal processing, generally in real-time. ... CDMA2000 is a family of third-generation (3G) mobile telecommunications standards that use CDMA, a multiple access scheme for digital radio, to send voice, data, and signalling data (such as a dialed telephone number) between mobile phones and cell sites. ... Interim Standard 95 (IS-95), is the first CDMA-based digital cellular standard pioneered by Qualcomm. ...

Cell sites are connected via copper facilities, optical fiber, or microwave. Copper facilities deliver either T1s or E1s, while microwave and optical fiber can offer T3s or Ethernet in addition to T1s or E1s. Copper facilities and optical fiber are usually provided as part of a service from the incumbent telephone company, but microwave is generally self-built by the mobile telephone company. Whatever the connection, the next elements in the mobile telephone network are Base Station Controllers (BSCs) and Radio Network Controllers (RNCs) at the mobile telephone switching office (MTSO). The base station controller is connected to a telephone switch, which is connected to the public switched telephone network (PSTN), while the Radio Network Controller handles 3G service, and is connected to Serving GPRS Support Node (SGSN), which is in turn connected to a data network, a telephone switch, or both. General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic pinkish red Standard atomic weight 63. ... Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by confining as much light as possible in a propagating form. ... Microwaves are electromagnetic waves with wavelengths longer than those of terahertz (THz) frequencies, but relatively short for radio waves. ... Digital signal 1 (DS1, also known as T1, sometimes DS-1) is a T-carrier signaling scheme devised by Bell Labs. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... A Digital Signal 3 (DS3) is a digital signal level 3 T-carrier. ... Ethernet is a large, diverse family of frame-based computer networking technologies that operates at many speeds for local area networks (LANs). ... A telephone company (or telco) provides telecommunications services such as telephony and data communications. ... The Base Station Subsystem (BSS) is the section of a GSM network which is responsible for handling traffic and signaling between a mobile phone and the Network Switching Subsystem. ... The Radio Network Controller (or RNC) is the governing element in the UMTS radio access network (UTRAN) responsible for control of the Node-Bs, that is to say the base stations which are connected to the controller. ... In the field of telecommunications, a central office houses equipment that is commonly known as simply a switch, which is a piece of equipment that connects phone calls. ... It has been suggested that Office classification be merged into this article or section. ... 3G is third-generation technology in the context of mobile phone standards. ... The GPRS system is used by GSM Mobile phones, the most common mobile phone system in the world (as of 2004), for transmitting IP packets. ...

Synonyms for "cell site" include "cell tower" (although many cell site antennas are not mounted on towers), and "mobile phone mast" (British English). "Base station" is sometimes used as a synonym as well, but this overlooks the increasing co-location of multiple mobile operators, and therefore multiple base stations, at a single cell site. Depending on an operator's technology choices, even a cell site hosting one mobile operator may house multiple base stations, each to serve a different air interface technology (TDMA or GSM, for example). British English (BrE, en-GB) is a broad term used to distinguish the forms of the English language used in the United Kingdom from forms used elsewhere. ... The term base station can be used in the context of land surveying, wireless computer networking, and wireless communications. ... Time Division Multiple Access (TDMA) is a technology for shared medium (usually radio) networks. ... Not to be confused with Get Some Mates The Global System for Mobile Communications (GSM) is the most popular standard for mobile phones in the world. ...

A controversial issue is whether there is a correlation between radio transmission and the risk of cancer. Safety regulations exist to protect the public from extensive exposure to radio waves emitted by cell sites.

Cell Site Range

The working range of a cell site - the range within which mobile devices can connect to it reliably is not a fixed figure. It will depend on a number of factors, including

• The type of signal in use (i.e. the underlying technology), similarly to the fact that AM radio waves reach further than FM radio waves.
• The transmitter's rated power.
• The transmitter's height.
• The array setup of panels may cause the transmitter to be directional or omni-directional.
• It may also be limited by local geographical or regulatory factors and weather conditions.

Generally, in areas where there are enough cell sites to cover a wide area, the range of each one will be set to: Log-periodic dipole array A directional antenna is an antenna which transmits or receives maximum power in a particular direction. ... An omnidirectional antenna is an antenna system which radiates power uniformly in one plane with a directive pattern shape in a perpendicular plane. ...

• Ensure there is enough overlap for "handover" to/from other sites (moving the signal for a mobile device from one cell site to another, for those technologies that can handle it - e.g. making a GSM phone call while in a car or train).
• Ensure that the overlap area is not too large, to minimize interference problems with other sites.

The maximum range of a site (where it is not limited by interference with other sites nearby) depends on the same circumstances. Some technologies, such as GSM, have a fixed maximum range of 25 miles (40 km), which is imposed by technical limitations. CDMA and iDEN have no built-in limit, but the limiting factor is really the ability for a low-powered personal cell phone to transmit back to the cell site. As a rough guide, based on a tall site and flat terrain, it is possible to get between 30 to 45 miles (50-70 km). When the terrain is hilly, the maximum distance can vary from as little as 3 to 5 miles (5-8 km). [1]

In practice, cell sites are grouped in areas of high population density, with the most potential users. Cell phone traffic through a single cell site is limited by the site's capacity (there is a finite number of calls that a site can handle at once), and this limitation is another factor affecting the spacing of cell sites. In suburban areas, sites are commonly spaced 1-2 miles apart, and in dense urban areas, sites may be as close as ¼-½ mile apart. Despite reaching traffic limitations, cell sites always reserve available bandwidth for emergency calls.

External link

• FCC: Information On Human Exposure To Radio frequency Fields From Cellular and PCS Radio Transmitters