4G, we are more common is LTE, and LTE has two branches, LTE-TDD (also known as TD-LTE) and LTE-FDD (also known as FDD-LTE).
TD-LTE and FDD-LTE occupy different working frequencies respectively, and also divide the wireless frequency into different frequency bands. Among them, TD-LTE has only a single frequency because it is time-division duplex, and does not distinguish between uplink and downlink. In FDD-LTE, the uplink and downlink are separated, so the frequency band specifies both the uplink and downlink usage ranges. 4G LTE 725-770MHz is the most commonly used frequency band in 4G communication networks. Of course, it is also distributed in the jammer frequency band. As the most commonly used frequency band, 725-770MHz has always been the most important frequency band before 5G distribution.