**2.5 Duplexing schemes in 5G NR**

5G NR supports both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) schemes. TDD is the main duplexing mode for higher frequencies while FDD is used for lower frequencies as the interference problems with large cells is reduced by having different frequencies in UL and DL. FDD is similar to FDM, UL and DL use separate carrier frequencies. Data are transmitted in both directions simultaneously. TDD is similar to TDM, only one carrier frequency is used. Transmission/Reception in UL and DL is assigned by different time slots.
