ARFCN
Encyclopedia
In GSM cellular networks, an absolute radio-frequency channel number (ARFCN) is a code that specifies a pair of physical radio carriers and channels used for transmission and reception on the Um interface
, one for the uplink signal and one for the downlink signal. ARFCNs are defined in GSM Specification 45.005 Section 2.
Each ARFCN has a bandwidth of 270.833 kHz. ARFCNs use a channel spacing of 200 kHz in any given GSM band. Uplink-downlink spacing is typically 45 or 50 MHz.
Different frequencies (ARFCNs) are used for the frequency-based component of GSMs multiple access scheme (FDMA — frequency-division multiple access
). Together with the time-based component (TDMA — time division multiple access
) the physical channel is defined by selecting a certain ARFCN and a certain time slot. Note not to confuse this physical channel with the logical channels (e.g. BCH — Broadcast Control Channel
) that are time-multiplexed onto it under the rules of GSM Specification 05.03.
Um Interface
The Um interface is the air interface for the GSM mobile telephone standard. It is the interface between the mobile station and the Base transceiver station . It is called Um because it is the mobile analog to the U interface of ISDN. Um is defined in the GSM 04.xx and 05.xx series of...
, one for the uplink signal and one for the downlink signal. ARFCNs are defined in GSM Specification 45.005 Section 2.
Each ARFCN has a bandwidth of 270.833 kHz. ARFCNs use a channel spacing of 200 kHz in any given GSM band. Uplink-downlink spacing is typically 45 or 50 MHz.
Different frequencies (ARFCNs) are used for the frequency-based component of GSMs multiple access scheme (FDMA — frequency-division multiple access
Frequency-division multiple access
Frequency Division Multiple Access or FDMA is a channel access method used in multiple-access protocols as a channelization protocol. FDMA gives users an individual allocation of one or several frequency bands, or channels. It is particularly commonplace in satellite communication. FDMA, like...
). Together with the time-based component (TDMA — time division multiple access
Time division multiple access
Time division multiple access is a channel access method for shared medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This...
) the physical channel is defined by selecting a certain ARFCN and a certain time slot. Note not to confuse this physical channel with the logical channels (e.g. BCH — Broadcast Control Channel
Broadcast Control Channel
The broadcast control channel is a point to multipoint, unidirectional channel used in the Um Interface of the GSM cellular standard....
) that are time-multiplexed onto it under the rules of GSM Specification 05.03.