Question: In E-UTRA, when using ROHC for header compression on a DAPS (Dual Active Protocol Stack) bearer, how does the PDCP entity determine which cell's ROHC configuration to use for compressing a PDCP SDU?
Option 1: Based on whether the PDCP SDU is transmitted to the source cell or the target cell.
Option 2: Always based on the source cell's ROHC configuration, regardless of transmission direction.
Option 3: Always based on the target cell's ROHC configuration, regardless of transmission direction.
Option 4: Randomly selects between the source and target cell's ROHC configurations for each PDCP SDU.
Explanation: This is because, according to the specifications, for DAPS bearers, the PDCP entity shall perform header compression using the ROHC protocol configured for either the source cell or the target cell, based on to which cell the PDCP SDU is transmitted. This ensures seamless handover and optimal performance by adapting to the current transmission context.