A Novel Probabilistic Access Scheme for NB-IoT in 5G Networks

As one of the emerging technologies of Low-Power Wide-Area Internet of Things, Narrow-Band Internet of Things (NB-IoT), is facing more and more challenges of massive terminal connections. Aiming at practical application scenarios, a preamble allocation scheme based on Beta distribution is proposed. This scheme first calculates the energy consumption of equipment's each time slot, and divides the equipment into high energy consumption equipment group and low energy consumption equipment group based on the average energy consumption and cumulative energy consumption. And then assign the preamble to the group of high energy consumption devices preferentially, then assign the remaining preamble and the conflicting preamble of the high energy consumption device group will be assigned to low energy consumption device group. The simulation result shows that, compared with traditional random allocation scheme, the proposed scheme can effectively improve NB-IoT, in terms of average access success rate and average throughput of the system, also can effectively reduce the back-off time.