How to deploy MEC NEs conveniently and quickly, and realize flexible and efficient traffic offloading is a key issue for carriers to consider. At present, there are three mainstream 5G distribution technologies: LADN (Local Area Data Network) solution, UL-CL (Uplink Classifier) solution and Multi-homing solution.
Based on the C/U separation architecture of the 5G core network, the UPF needs to be deployed at the network edge to reduce the transmission delay and implement local distribution of data traffic. Control-plane functional NEs, such as the SMF, is deployed in the central DC in a centralized manner to control the UPF deployed in the MEC, configure and deliver traffic distribution policies.
Figure 1 UPF Distribution
5G user plane UPF is deployed to implement traffic offloading. Local MEC AF informs the PCF of the UPF traffic offloading rule through the N5/N33 interface. PCF configures the traffic distribution policy to the SMF, and SMF performs centralized scheduling of all traffic. It uses such solutions as LADN, UL-CL or Multi-Homing to implement the traffic offloading of the edge UPF, and unload the local traffic to be distributed through the local edge UPF. Non-local traffic is sent to the central UPF through the local UPF for processing. This avoids alternative traffic to central networks, reduces the pressure of backbone network transmission and network construction costs, and improves on-net packet data bearing efficiency and user experience.