Multiple Resource Units Allocation and Scheduling with QoS Guarantees for NB-IoT systems

In Narrowband Internet-of-Things (NB-IoT) systems, resource units (RUs) including five forms are defined as the scheduling units in narrowband physical uplink shared channel (NPUSCH), which causes resource fragmentation and intolerable delay when the multiple RUs are scheduled in arbitrary manner. In this paper, we propose a multiple RUs allocation and scheduling scheme with quality-of-service (QoS) guarantee for NB-IoT systems, which achieves higher resource efficiency and satisfies access delay requirements in a co-existing environment of both delay-sensitive and delay-tolerant services. Firstly, a multiple RUs allocation criterion depending on the QoS requirements for five types of services is proposed. Secondly, based on the proposed criterion, the multiple RUs scheduling is formulated as a two-dimensional packing problem and an effective multiple RUs placement algorithm with QoS guarantee is designed as an approximate solution to maximize resource efficiency. Finally, simulation results demonstrate that our scheme can significantly improve the resource efficiency and satisfy the access delay for each type of service.