23.1 General

Sub-Band Full Duplex (SBFD) operation is supported for a TDD carrier, enabling simultaneous downlink transmission and uplink reception at the gNB on their non-overlapping respective sub-bands. From UE perspective, full duplex is not supported. The configurations of cell-specific SBFD time and frequency resources are provided through SIB1 or dedicated signalling.

A UE can be semi-statically configured with SBFD sub-bands in downlink symbols and flexible symbols provided by tdd-UL-DL-ConfigurationCommon and this UE is referred to as an SBFD aware UE. The maximum number of UL sub-bands for SBFD operation in an SBFD symbol within a TDD carrier is one. The maximum number of DL sub-bands for SBFD operation in an SBFD symbol within a TDD carrier is two. A UE can be configured with SBFD sub-bands in at most one TDD carrier in multi-carrier scenario.

In an SBFD symbol, except for cross-link interference measurements, a UE transmits or receives only in RBs that are both in the active UL BWP and in the UL sub-band, or both in the active DL BWP and the DL sub-band(s), respectively.

A UE can be configured to transmit or receive only in non-SBFD symbols, only in SBFD symbols, or across both SBFD symbols and non-SBFD symbols for multiple transmission or reception occasions.