Packet Level Resilience for the User Plane in 5G Networks

TL;DR

This work tackles URLLC reliability in private 5G networks by preventing user-plane packet loss through packet-level redundancy. It leverages PREOF to realize a $1+1$ protection scheme across disjoint paths, with replication at a local edge (gNB or UE) and elimination plus in-order delivery at the tail end; reordering is offloaded to an external server (PTE-O). An optional protection proxy enables traffic engineering in the UPF, and two deployment paths—gNB-based and UE-based PTI—are analyzed for tradeoffs in latency, energy, and complexity. The authors outline a roadmap toward practical evaluation using open-source cores (e.g., free5GC), P4-based hardware, and DPDK/eBPF offloading to quantify feasibility in real networks.

Abstract

The growing demands of ultra-reliable and low-latency communication (URLLC) in 5G networks necessitate enhanced resilience mechanisms to address user plane failures caused by outages, hardware defects, or software bugs. An important aspect for achieving ultra-reliable communication is the redundant transmission of packets, as also highlighted in 3GPP Release 18. This paper explores leveraging the Packet Replication, Elimination, and Ordering Function (PREOF) to achieve 1+1 path protection within private 5G environments. By extending existing 5G components with mechanisms for packet level redundancy and offloading the reordering mechanism to external servers, the proposed approach ensures minimal packet loss in case of a failure. A conceptual integration of redundant paths and programmable elements is presented, with considerations for deployment in existing 5G infrastructures and the trade-offs of latency versus enhanced traffic engineering. Future work aims to evaluate practical implementations using an open source 5G core, P4-based hardware and offloading technologies like DPDK and eBPF.

Figures (1)

• Figure 1: Overview of a 5G core network incorporating redundant data paths and UPF using the PREOF mechanism.