Question: What is the primary purpose of the 'UE RADIO CAPABILITY MATCH REQUEST' message in UTRAN's Iu interface, as initiated by the Serving GPRS Support Node (SGSN)?
Option 1: To request compatibility checks between User Equipment (UE) radio capabilities and the network's current configuration.
Option 2: To update the Radio Network Controller (RNC) with new UE location information for handover preparation.
Option 3: To establish a connectionless signalling bearer for efficient data transmission.
Option 4: To notify the RNC about changes in SGSN's capacity for load balancing.
Explanation: The correct answer, Option 1, aligns with the purpose of ensuring compatibility between the UE's radio capabilities and the network's setup, which is crucial for maintaining seamless and efficient communication services. This process helps in preventing potential connectivity issues that could arise from mismatches between UE capabilities and network expectations.