Question: For a User Equipment (UE) reporting its sTTI-SupportedCombinations-r15, how are the TTI length combinations ordered when indicated for two PUCCH groups?
Option 1: UL first followed by DL for both primary and secondary PUCCH groups.
Option 2: Primary PUCCH group's DL and UL together, then secondary PUCCH group's DL and UL together.
Option 3: Secondary PUCCH group's DL and UL reported before the primary PUCCH group's.
Option 4: DL first followed by UL for each PUCCH group, starting with the primary PUCCH group.
Explanation: According to the specifications, when reporting sTTI-SupportedCombinations-r15 for two PUCCH groups, the support for the primary PUCCH group is indicated first. A TTI length combination is reported with DL (Downlink) first followed by UL (Uplink), ensuring clarity in capability reporting per band or band combination, including non-CA bands. Thus, the correct sequence is Downlink followed by Uplink for each group, prioritizing the primary PUCCH group.