Joint Routing and Packet Scheduling For URLLC and eMBB traffic in 5G O-RAN

Open Radio Access Network (O-RAN) is an innovative RAN architecture designed to revolutionize 5G-and-beyond mobile networks. O-RAN virtualizes the fronthaul network functions into Open Centralized Unit (O-CU), Open Distributed Unit (O-DU) and Open Radio Unit (O-RU). Unfortunately, there is no standard data communication mechanism to disaggregate Quality of Service (QoS) flow traffic into multiple routes to access O-DUs to leverage the distributed computing capability. Furthermore, there is no centralized scheduler to coordinate processors that are processing O-DU functions efficiently to meet fifth generation (5G) QoS services. Therefore, O-RAN performance is still questionable. This paper investigates an optimized solution for joint Routing and Packet Scheduling (RPS) which is implemented in the O-DU pool to replace individual O-DUs. We formulate two joint RPS problems to coordinate multiple routes and multiple parallel processors in the centralized O-DU pool to accommodate the Ultra-Reliable Low Latency Communications (URLLC) and enhanced Mobile Broadband (eMBB) services. We propose a greedy algorithm and a Min-Max algorithm to approximate the optimal result. Numerical results show that our proposed solution improves significantly system processing delay compared with a scheme of individual O-DUs which are selfishly maximized.