mid gap

The term center gap is used for certain frequency ranges that lie between the uplink and downlink frequencies of mobile communications networks in which no radio transmission has taken place to date.

In mobile communications systems, a security frequency band is located between the transmission frequencies for the uplink and downlink. Since all possible frequencies should be used for radio services in the interests of frequency economy, the German Federal Network Agency(BNetzA) has released the frequency band that serves as the safety margin in Long Term Evolution( LTE) for use for radio microphones.

The various LTE providers use the UHF range between 791 MHz to 861 MHz. Within this range, there is a frequency band gap between 823 MHz and 832 MHz that was released for radio microphones in 2011 and is referred to as the center gap. Another center gap released for radio microphones is between 1,785 MHz and 1,805 MHz. This center gap is defined in the GSM standard between the uplink from 1,710 MHz to 1,785 MHz and the downlink from 1,805 MHz to 1,880 MHz.