Question: In the context of SRNS Context Forwarding to Target RNC from CN during a handover via the CN in UTRAN Iu interface, what information is included in the SRNS contexts for each referenced RAB when available?
Option 1: Only the next GTP-PDU sequence numbers for downlink transmission
Option 2: Source RNC PDCP context info exclusively
Option 3: Both GTP-PDU sequence numbers (uplink and downlink) and next PDCP sequence numbers (for sending and receiving data from UE), plus source RNC PDCP context info if available
Option 4: None of the above, only RAB IDs are sent
Explanation: This option is correct because SRNS contexts sent for each referenced RAB include comprehensive sequence number information (both GTP-PDU for uplink and downlink, and next PDCP sequence numbers for data transmission and reception from UE) when available. Additionally, if source RNC PDCP context info is available, it is also included in the forwarding process to ensure seamless handover and maintain data integrity across the network transition.