Base transceiver station

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BTS device, model "BS11µBTS" from Siemens
BTS antenna mast

A Base Transceiver Station ( BTS ; German base transceiver station ) is a network element in the base station subsystem of the digital GSM - the mobile radio network . It is also known as a GSM base station . The correspondence to the BTS in a UMTS -Netz is the Node-B .

A BTS supplies at least one radio cell . In practice, systems are usually set up that combine 3 or 6, but rarely also 4, radio cells. In these cases, sector antennas are used that specifically supply an area usually between 60 ° and 120 °, the so-called sector.

One to five frequencies are usually used in a radio cell , rarely up to eight. The theoretical, technical-related maximum is 18 frequencies in a radio cell.

The range of a BTS is under practical conditions, due to the path loss , between a few hundred meters and a few kilometers. Since the signal propagation time between base station and mobile station has to be compensated for by the parameter timing advance , the theoretically maximum reachable range is 35.41 km, with GSM 400 121.73 km. By means of a special configuration, which however has an influence on the cell capacity, the increased range of a GSM 400 cell can also be achieved in the cells of all other GSM standards.

The base station is mainly used for transmission over the air interface; the control and monitoring functions are largely performed by the base station controller (BSC).


The tasks of a BTS are:

  • Provision of signals to enable end devices to be synchronized with the station ( frequency correction bursts in FCCH , synchronization bursts in SCH )
  • Activation and deactivation of the assigned frequency channels
  • Implementation of frequency hopping
  • Encryption and decryption of transmission and control channels using A5
  • Determination and assignment of timing advance
  • Determination of the reception level and the reception quality
  • Signal adaptation to the PCM interface via which the connection to the BSC and the MSC is established.

Web links

Commons : Cellular Base Stations  - Collection of pictures, videos and audio files

Individual evidence

  1. Nortel Networks: Technical Specifications of the GSM Base Transceiver Station (BTS) 18000 ( English ) Archived from the original on 13 November 2006. Accessed September 15, 2009: "Up to 18 TRX in one single cabinet, Up to 3 radio cabinets "
  2. 3GPP TS 45.002: Multiplexing and multiple access on the radio path ( English , ZIP / DOC; 610 kB) December 18, 2009. Accessed January 24, 2010.
  3. 3GPP TS 45.010: Radio subsystem synchronization ( English , ZIP / DOC; 209 kB) December 18, 2009. Accessed January 5, 2010.
  4. a b 3GPP TR 43.030: Radio network planning aspects ( English , ZIP / DOC; 184 kB) December 18, 2009. Accessed January 24, 2010.