A base transceiver station (BTS) is a piece of equipment that facilitates
wireless communication between
user equipment (UE) and a network. UEs are devices like
mobile phone
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket 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 whil ...
s (handsets),
WLL phones, computers with
wireless Internet connectivity, or antennas mounted on buildings or telecommunication towers.
The network can be that of any of the wireless communication technologies like
GSM,
CDMA,
wireless local loop,
Wi-Fi
Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wave ...
,
WiMAX
Worldwide Interoperability for Microwave Access (WiMAX) is a family of wireless broadband communication standards based on the IEEE 802.16 set of standards, which provide physical layer (PHY) and media access control (MAC) options.
The WiMAX ...
or other
wide area network
A wide area network (WAN) is a telecommunications network that extends over a large geographic area. Wide area networks are often established with leased telecommunication circuits.
Businesses, as well as schools and government entities, us ...
(WAN) technology.
BTS is also referred to as the ''
node B
{{Unreferenced, date=May 2019, bot=noref (GreenC bot)
Node B is the telecommunications node in particular mobile communication networks, namely those that adhere to the UMTS standard. The Node B provides the connection between mobile phones ( UEs) ...
'' (in
3G networks) or, simply, the ''
base station
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 term is used in the context of mobile telephony, wireless com ...
'' (BS). For discussion of the
LTE
LTE may refer to:
Science and technology
* LTE (telecommunication) (Long-Term Evolution), a telephone and mobile broadband standard
** LTE Advanced, an enhancement
*** LTE Advanced Pro
* Compaq LTE, a line of laptop computers produced by Compaq
* ...
standard the abbreviation ''
eNB'' for evolved node B is widely used, and GNodeB for
5G.
Though the term BTS can be applicable to any of the wireless communication standards, it is generally associated with mobile communication technologies like
GSM and
CDMA. In this regard, a BTS forms part of the
base station subsystem (BSS) developments for system management. It may also have equipment for
encrypting and decrypting communications, spectrum filtering tools (band pass filters) and so on.
Antennas may also be considered as components of BTS in general sense as they facilitate the functioning of BTS. Typically a BTS will have several transceivers (TRXs) which allow it to serve several different frequencies and different sectors of the cell (in the case of sectorised base stations). A BTS is controlled by a parent
base station controller via the base station control function (BCF). The BCF is implemented as a discrete unit or even incorporated in a TRX in compact base stations. The BCF provides an operations and maintenance (O&M) connection to the
network management system
Network monitoring is the use of a system that constantly monitors a computer network for slow or failing components and that notifies the network administrator (via email, SMS or other alarms) in case of outages or other trouble. Network monitorin ...
(NMS), and manages operational states of each TRX, as well as software handling and alarm collection. The basic structure and functions of the BTS remains the same regardless of the wireless technologies.
General architecture
A BTS is usually composed of:
; Transceiver (TRX): Provides transmission and reception of signals. It also does sending and reception of signals to and from higher network entities (like the base station controller in mobile telephony).
; Power amplifier (PA): Amplifies the signal from TRX for transmission through antenna; may be integrated with TRX.
; Combiner: Combines feeds from several TRXs so that they could be sent out through a single antenna. Allows for a reduction in the number of antenna used.
; Multiplexer: For separating sending and receiving signals to/from antenna. Does sending and receiving signals through the same antenna ports (cables to antenna).
; Antenna: This is the structure that the BTS lies underneath; it can be installed as it is or disguised in some way (concealed
cellular sites).
; Alarm extension system: Collects working status alarms of various units in the BTS and extends them to operations and maintenance (O&M) monitoring stations.
; Control function: Controls and manages the various units of BTS, including any software. On-the-spot configurations, status changes, software upgrades, etc. are done through the control function.
; Baseband receiver unit (BBxx): Frequency hopping, signal DSP.
Terms regarding a mobile BTS
; Diversity techniques: To improve the quality of the received signal, often two receiving antennas are used, placed at a distance equal to an odd multiple of a quarter of the corresponding wavelength. For 900 MHz, this wavelength is 33 cm. This technique, known as antenna diversity or
space diversity
Antenna diversity, also known as space diversity or spatial diversity, is any one of several wireless diversity schemes that uses two or more antennas to improve the quality and reliability of a wireless link. Often, especially in urban and ind ...
, avoids interruption caused by path
fading
In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process. A fading channel is a ...
. The antennas can be spaced horizontally or vertically. Horizontal spacing requires more complex installation, but brings better performance.
: Other than antenna or space diversity, there are other
diversity techniques such as frequency/time diversity, antenna pattern diversity, and polarization diversity.
: Splitting refers to the flow of power within a particular area of the cell, known as a sector. Every field can therefore be considered like one new cell.
Directional antennas reduce LoRa (long-range) interference. If not sectorised, the cell will be served by an
omnidirectional antenna, which radiates in all directions. A typical structure is the trisector, also known as clover, in which there are three sectors served by separate antennas. Each sector has a separate direction of tracking, typically of 120° with respect to the adjacent ones. Other orientations may be used to suit the local conditions. Bisectored cells are also implemented. These are most often oriented with the antennas serving sectors of 180° separation to one another, but again, local variations do exist.
Gallery
See also
*
Mobile cell sites
Mobile cell sites are infrastructures transportable on trucks, allowing fast and easy installation in restricted spaces. Their use is strategic for the rapid expansion of cellular networks putting into service point-to-point radio connections as w ...
*
OpenBTS
*
Cell ID
A GSM Cell ID (CID) is a generally unique number used to identify each base transceiver station (BTS) or sector of a BTS within a location area code (LAC) if not within a GSM network.
In some cases the first or last digit of CID represents cells ...
Further reading
*
External links
*
References
{{Reflist
Wireless networking