The base station identity code (BSIC), is a code used in GSM to uniquely identify a

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 ...

. The code is needed because it is possible that mobile stations receive the broadcast channel of more than one base station on the same frequency. This is due to frequency re-use in a

cellular network A cellular network or mobile network is a communication network where the link to and from end nodes is wireless. The network is distributed over land areas called "cells", each served by at least one fixed-location transceiver (typically thre ...

. The BSIC is defined in GSM specification 03.03 section 4.3.2. Each base-station has its own BSIC, this code is at all times transmitted on the broadcast channel, so the mobile stations can distinguish between base stations. The BSIC is composed of a 3-bit network color code (NCC) and a 3-bit base station color code (BCC). The NCC is assigned to each network provider so the MS can sort out which base-stations it is allowed to camp on. The NCC of different providers must be different, also in national border-areas. The BCCHs (broadcast control channel) of each base stations are assigned frequencies by the

network operator A mobile network operator (MNO), also known as a wireless service provider, wireless carrier, cellular company, or mobile network carrier, is a provider of wireless communications services that owns or controls all the elements necessary to sell ...

, and must be assigned such that no neighbor stations have equal BCCH and thus equal BSIC. As long as base stations use different

frequencies Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...

for their broadcasting channel, there is no problem in using the same base station identity code. Unique identification of a base station is especially important in border areas, where at both sides of the border there is a different operator who might use the same broadcasting channel on the same frequency.

References

{{Reflist
3GPP TS 03.03 Numbering, Addressing and Identification

External links

Cellular Signal Booster
GSM standard Mobile telecommunications