What's EARFCN

EARFCN stands for "E-UTRA Absolute Radio Frequency Channel Number". It is a channel identification number used in the LTE (Long-Term Evolution) mobile communication system to identify a specific radio frequency channel.

Unlike the ARFCN used in GSM and UMTS, the EARFCN in LTE is not a direct representation of the frequency. Instead, it is a virtual channel number that represents the carrier frequency in relation to a reference frequency. The reference frequency is the center frequency of the baseband signal, which is fixed and known in the LTE system.

The EARFCN is used to identify the uplink and downlink frequency for a given LTE channel. Each EARFCN corresponds to a specific uplink and downlink frequency pair and a specific channel bandwidth. The channel bandwidths for LTE are typically 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz.

For example, EARFCN 650 corresponds to an uplink frequency of 1710 MHz and a downlink frequency of 2110 MHz, with a channel bandwidth of 10 MHz.

In summary, EARFCN is a channel identification number used in the LTE mobile communication system to identify a specific radio frequency channel. It is a virtual channel number that represents the carrier frequency in relation to a reference frequency, and it corresponds to a specific uplink and downlink frequency pair and a specific channel bandwidth.