Feedback Control for QoS-Aware Radio Resource Allocation in Adaptive RAN

In order to meet the quality requirements of various communication services in the advanced 5G era around 2025, the authors have proposed an Adaptive radio access network (RAN) that changes the placement of virtualized base station functions according to the services. In Adaptive RAN, each base station function has its own scheduler, and multiple schedulers share common radio resources. Therefore, in order to guarantee communication quality for more users, it is necessary to control the allocation of the radio resources required for scheduling to each base station function with neither excess nor deficiency. This allocation control is performed based on the information collected from the base station functions by the RAN intelligent controller (RIC). If a large amount of information is used for control, allocation can be performed with higher accuracy, but the collection of information overuses the limited bandwidth of the network. Therefore, it is necessary to reduce the information volume required for control while at the same time guaranteeing communication quality. In this paper, we propose a method that guarantees communication quality while reducing the information volume required for control by combining a required resource estimation control in a long cycle and a resource allocation modification control based on feedback information related to communication quality in a short cycle. We evaluated the impact of the proposed method on communication quality compared to conventional methods through simulation, and verified that the proposed method can guarantee better communication quality than conventional methods while suppressing the increase in information volume.