Efficient downstream data dissemination in IAB networks with DAG-based topology

Integrated access and backhaul (IAB) is a key technology to extend network coverage for fifth-generation (5G) mobile networks. To reduce the deployment cost, in an IAB network, base stations can be connected wirelessly. Previous studies propose to use a tree structure to construct route paths between base stations. We observe that by the tree structure, network congestion may occur and thus delay of disseminating downstream data will be lengthened. In this work, we connect base stations using a directed acyclic graph (DAG) topology. By the DAG, each base station can have multiple parents. We design a two-phase scheduling method to decide routing paths and assign radio resources to disseminate downstream data. The simulation results indicate that the proposed method can effectively reduce dissemination delay and increase network throughput.