Question: What is the main function of the ESM sublayer in EPS session management?
Option 1: To support the EPS bearer context handling in the UE and in the MME.
Option 2: To manage the radio resources between the UE and the eNodeB.
Option 3: To handle the user data transmission via the user plane between the UE and the PDN.
Option 4: To perform the authentication and authorization of the UE.
Explanation: The ESM sublayer plays a crucial role in EPS session management, primarily focusing on supporting the EPS bearer context handling in both the User Equipment (UE) and the Mobility Management Entity (MME). This involves managing the activation, deactivation, and modification of EPS bearer contexts, which are essential for establishing and maintaining connections between the UE and the Packet Data Network (PDN).