QoS Assurance in IAB Network

The 5th generation (5G) of wireless communications have stringent requirements on latency and data rate. To support this, the millimeter wave (mmWave) bands above 10 GHz have gained great attraction. However, considering the severe isotropic path loss and the harsh propagation experienced at such high frequencies, a dense base station deployment is required, which may be unrealistic due to the unavailability of fiber drops to provide wired backhauling. Integrated access and backhaul (IAB), where the wireless connection is used for the backhaul connection of base stations instead of fiber, is an attractive solution which could allow easier deployment of a dense network. In IAB, packets may be forwarded by multiple IAB nodes before arriving at the base station. Thus, how to guarantee the Quality of Service (QoS) requirement needs to be studied. In this work, we propose some QoS assurance methods based on three scenarios in IAB network. The first one is integration case, and we propose some methods to accelerate the access of IAB node. We consider that the IAB node is able to forward data for the others in the second scenario. To ensure the QoS requirements for different forwarded packets, we optimize the backhaul radio link control channel setup/modification procedure, and put forward some bearer mapping schemes. IAB node migration is considered as the third scenario due to the vulnerable wireless backhaul links. Simulation results demonstrate that some assistant information, e.g. hop count and load information, may help the integrated IAB node select a suitable parent node and thus satisfy the access latency requirement.