Absolute Radio Frequency Channel Number. An ARFCN defines a pair of Radio Frequency (RF) channel frequencies for uplink and downlink use. See 3GPP TS45.005 Section 2 for the ARFCN for GSM, TS25.101 Section 5.4 for the UARFCN for UMTS and TS36.101 Section 5.4 for the EARFCN for LTE. ARFCN and UARFCN are based on a 200 kHz channel raster, while EARFCN is based on a 100 kHz channel raster.