Question: In E-UTRA and EPC conformance testing for User Equipment (UE), what distinguishes the Paging test procedure for the PS (Packet Switched) domain from the initial assumption for the CS (Circuit Switched) domain?
Option 1: The use of a specific S-TMSI (Serving Temporary Mobile Subscriber Identity) for both domains.
Option 2: The PS domain uses an explicitly specified S-TMSI, while the CS domain's procedure is currently undefined (FFS - For Further Study).
Option 3: The number of retransmissions allowed before the test is considered failed.
Option 4: The type of NAS (Non-Access Stratum) messages exchanged during the test.
Explanation: This question requires understanding of the nuances between Packet Switched (PS) and Circuit Switched (CS) domains in E-UTRA and EPC testing. The correct answer highlights that for PS domain testing, a specific S-TMSI is used, whereas for CS domain, the test procedure itself is currently undefined, implying a significant distinction in how these domains are approached in paging tests.