Slicing and scheduling conflicts in 5G networks reduce unmet demand
Experimental Classification of xApp Conflicts in O-RAN: Slicing vs. Per-UE Scheduling
Networking and Internet Architecture
Summary
In 5G networks, different applications controlling the radio resources can accidentally ask for conflicting allocations that cannot all be satisfied at once. The authors studied how controlling resource slices and individual user scheduling can clash and cause inefficiencies. They built and tested a system that reallocates capacity dynamically from underused to busy slices, measuring conflicts and improvements on real hardware and simulations. Their method reduced unmet demand by up to a third and lowered wasted allocation, showing practical ways to detect and handle such conflicts in live 5G systems.
What this means in practice
- •For network operators: Improve dynamic resource management for 5G slices and users by detecting and reducing conflicting resource demands.
- •For telecom equipment developers: Integrate conflict detection logic for multi-granularity resource controls in 5G gNB software to enhance scheduler reliability.
Authors
Rashmi Sharan Sinha, Merim Dzaferagic, Marco Ruffini, Nima Afraz
Abstract
Concurrent applications (xApps) in the Near-Real-Time RAN Intelligent Controller (Near-RT RIC) of the Open Radio Access Network (O-RAN) can issue control intents that are jointly infeasible when they act on hierarchically coupled radio resources. This paper experimentally studies an interaction between slice-level physical resource block (PRB) allocation and per-user-equipment (UE) scheduling. We implement a utilisation-aware slicing control (the spectral-efficiency xApp) that reclaims a fixed fraction of the baseline allocation from under-utilised slices and redistributes pooled capacity to saturated slices. The control logic is exercised in simulation and on a 5G testbed comprising an OCUDU-based next-generation NodeB (gNB), an Open5GS core, a Universal Software Radio Peripheral (USRP) X310, and five commercial off-the-shelf (COTS) UEs. Because the gNB counters available in this testbed are UE-keyed but not slice-labelled, the slicing control derives a per-slice throughput proxy from core-side traffic measurements. A command-bus detector evaluates explicitly defined control-intent conditions: a per-UE floor above its parent-slice cap, aggregate UE floors above the cell budget, and repeated slice-target changes within a specified window. Over a 276-cycle continuous run, the detector logged 147 per-slice floor--cap violations, 49 shared-budget over-subscription episodes, and 11 allocation-oscillation episodes. Against the conventional static slice split replayed on the same load trace, the slicing control reduces unmet demand by 12--33\,\% and idle allocation by 21--23\,\%. The results demonstrate reproducible cross-granularity control-intent interactions on real hardware and provide an experimental basis for analysing conflict detection in O-RAN.