Multi-UE 5G RAN Measurements: A Gamut of Architectural Options
Andreas Ingo Grohmann, Mauri Seidel, Sebastian A.W. Itting, Ray‐Guang Cheng, Martin Reisslein, Frank H. P. Fitzek
Abstract
The Radio Access Network (RAN) of Fifth Generation (5G) communication systems critically influences the overall performance and cost of a 5G system. 5G RANs allow for a gamut of implementations ranging from closed (carrier-grade) implementations by traditional vendors that are expensive and configured by the vendor to RANs that are compliant with the specifications of the O-RAN ALLIANCE, i.e., to so-called O-RANs. O-RANs are available in closed-source and open-source implementations; O-RANs can be configured by the operator and are cheaper than the closed RANs. Understanding the packet-level performance characteristics of these different 5G RAN implementations is a prerequisite for informed network planning and deployment, particularly for Non-Public Networks (NPNs) for specific use cases. Existing measurement studies have mainly considered a single User Equipment (UE); however, practical networks typically operate with multiple UEs. We conduct packet-level measurements for concurrent over-the-air transmissions to (downstream) and from (upstream) multiple UEs for a wide range of packet transmission rates. We consider current representative implementations of three RAN architectural options: closed RAN (based on Nokia system), closed-source O-RAN (based on Airspan system), and open-source O-RAN (based on srsRAN Project system). We find that the one-way packet delays and the packet loss probabilities can vary sharply among the multiple concurrently operating UEs (which are identical in model and configuration) in the closed RAN and open-source O-RAN; whereas, the packet-level performance tends to be more consistent among the UEs in the closed-source O-RAN. Our measurement results provide a baseline for future research on refining RAN operations for multiple concurrent packet flows.