Two stage downlink scheduling for balancing QoS in multihop IAB networks

The 3GPP has envisioned Integrated Access and Backhaul (IAB) as a key enabler to support the flexible and ultra-dense deployment of 5G cells with significantly reduced deployment costs. However, IAB introduces new research challenges, especially when studying multihop topology. This paper presents a QoS-based downlink scheduler designed explicitly for IAB networks. The scheduler is devised after considering multihop relaying topology, QoS requirements, and backhaul constraints. We investigate its performance using system-level simulations under diverse IAB topologies. The performance results show that the scheduler is capable of fulfilling QoS requirements for different types of services, even at heavy network load. The scheduler also maintains excellent fairness among QoS flows belonging to the same service type.