ARFCN
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 05.05 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.
Referensi
- http://en.wikipedia.org/wiki/Absolute_radio-frequency_channel_number
- http://www.aubraux.com/design/arfcn-calculator.php