Question: In a 3GPP network, which of the following scenarios triggers the establishment of a new IP-CAN Session during Gateway Control session setup for a User Equipment (UE)?
Option 1: Handover from a non-3GPP access to a 3GPP access
Option 2: BBERF (BroadBand Edge Router Function) relocation in an existing PDN Connection
Option 3: UE's periodic procedure for updating its location in the EPC (Evolved Packet Core)
Option 4: Initial UE attachment to the EPC or establishment of a new PDN (Packet Data Network) Connection
Explanation: According to telecom network principles, when a UE attaches to the EPC for the first time or establishes a new PDN Connection, it necessitates setting up a new IP-CAN Session as part of the Gateway Control session establishment. This ensures proper allocation of resources and policy enforcement for the new connection. Options 1, 2, and 3 might involve updates or handovers but do not inherently require establishing a new IP-CAN Session in the context of Gateway Control session setup as described.