Rethinking the PDU Session Management Design in the Next Generation Mobile Networks

Traditionally, the design of Packet Data Unit (PDU) session management has been based on the premise that the Radio Access Network (RAN) and core networks are separate domains. In the 5G architecture, although sessions are managed by the Session Management Function (SMF), all relevant messages are funneled through the Access and Mobility Management Function (AMF), which acts as a single anchor point connecting to the RAN. This introduces several issues in terms of signaling performance and implementation. With the convergence of the RAN and core networks, parts of the RAN can now be software-defined and deployed in cloud data centers, while core networks can be distributed to the edge to reduce latency. This work is the first attempt to explore a new design of PDU session management to leverage these architectural changes. By incorporating the RAN into the current service-based architecture, session management procedures can bypass the AMF. We implement a proof-of-concept (PoC) system and conduct an initial experiment to demonstrate the benefits of this new approach. The experiment results show that the new design significantly reduces PDU session establishment time.