Question: What is the primary purpose of creating an association between the SGSN (Serving GPRS Support Node) and MSC/VLR (Mobile Switching Center/Visitor Location Register) when the optional Gs interface is installed?
Option 1: To enable coordination of MSs (Mobile Stations) that are both GPRS-attached and IMSI-attached, facilitating combined procedures to save radio resources.
Option 2: To exclusively manage E-UTRAN access for MSs, ensuring seamless handovers between different network modes.
Option 3: To isolate GPRS traffic from CS (Circuit Switched) traffic, improving network security.
Option 4: To bypass the SGSN for direct communication between the MS and MSC/VLR for certain services.
Explanation: The correct answer is Option 1 because the association between SGSN and MSC/VLR is utilized to coordinate activities of Mobile Stations that are attached to both GPRS (General Packet Radio Service) and IMSI (International Mobile Subscriber Identity) networks. This coordination enables combined attach/detach procedures, updates (e.g., Location Area/Routeing Area), paging for CS connections, and other informational procedures, all of which contribute to efficient use of radio resources. The mention of independence from E-UTRAN access support in the MS (Option 2) is a note but not the primary purpose. Options 3 and 4 misinterpret the role of the SGSN-MSC/VLR association.