Question: What is the purpose of the reverse mapping procedure performed by the MME in order to find the UE context?
Option 1: To create a new GUTI and send it to the SGSN.
Option 2: To retrieve information regarding the UE from the old SGSN.
Option 3: To map the RAI, P-TMSI (or TLLI) and the P-TMSI Signature sent by the SGSN to create the GUTI and compare it with the stored GUTI.
Option 4: To update the UE context in the MME.
Explanation: The reverse mapping procedure is performed by the MME to map the RAI, P-TMSI (or TLLI) and the P-TMSI Signature sent by the SGSN to create the GUTI and compare it with the stored GUTI. This allows the MME to find the UE context and retrieve information regarding the UE.