Question: In Dual Connectivity (DC) scenarios with the Secondary Cell Group (SCG) bearer option, what is the primary purpose of the Master eNB (MeNB) communicating path updates to the Mobility Management Entity (MME) during bearer context transfer between eNBs?
Option 1: To trigger a Serving Gateway (S-GW) relocation for all affected E-RABs.
Option 2: To update the downlink path for relevant E-RABs towards the Evolved Packet Core (EPC) without altering the uplink endpoint.
Option 3: To initiate a handover procedure for UEs connected to the target eNB.
Option 4: To request additional radio resources from the target eNB for the transferred bearer contexts.
Explanation: In DC scenarios with the SCG bearer option, when bearer contexts are transferred between eNBs, the MeNB must update the EPC on the new downlink path for the affected E-RABs. This ensures seamless data delivery without necessarily changing the Serving Gateway's uplink endpoint, which would otherwise alter the network's routing configuration unnecessarily.