A Realistic Coordinated Scheduling Scheme for the Next-Generation RAN

The design of the 5G next-generation radio access network (NG-RAN) proposes the division of the next- generation eNodeB (gNB) into centralized and distributed units. Centralization should facilitate coordination of RAN functions between gNBs, but the actual benefits of it are still unclear. In this paper, we provide a study of the feasibility and benefits of coordinated downlink scheduling. We first analyze the time constraints that a coordinated scheduler has to face from a theoretical perspective, and we back them with an experimental proof-of-concept. Then, we present a lightweight scheme for coordinated link adaptation that matches the previous constraints. We show that coordination is indeed feasible with state- of-the-art technology, although very limited by time constraints. Finally, we show the results of our experimental testbed, which successfully implemented the described coordination scheme under the predicted constraints.