16.1.8 PUCCH cell switching for TDD cells

To reduce the delay for HARQ-ACK feedback for TDD operation with URLLC services, PUCCH cell switching for TDD cells is supported. The UE can be provided in each PUCCH group with a PUCCH switching SCell (PUCCH sSCell) that can be used for PUCCH transmission in addition to PCell / PSCell / PUCCH SCell. The applicable cell for PUCCH transmission to be either on PCell /PSCell / PUCCH SCell or the PUCCH sSCell at a time is either defined by:

• a higher layer configured semi-static time-domain pattern of the applicable cell for PUCCH transmission; or
• dynamic indication of the cell for PUCCH transmission through a PDCCH scheduling a PUCCH transmission.

The PUCCH cell switching is applicable to all UCI types when using the higher layer configured time-domain pattern, but is only applicable to HARQ feedback for the dynamic indication of the cell for PUCCH transmission through a PDCCH scheduling PUCCH.