5G On-Demand SI Acquisition Framework and Performance Evaluation

In LTE, the system information (SI) is periodically broadcast to UEs. To improve the utilization of wireless resources and the latency of SI acquisition, SI is categorized into minimum SI and other SI in the 5G NR network. Moreover, a new approach, on-demand SI delivery, is also specified in NR. This enables gNBs to transmit other SI only when the UEs request it.In this paper, the MSG1-based and MSG3-based on-demand SI delivery designs are discussed.Besides, the effects of the beam sweeping and the UE behavior, “Listen Before Request”, are also considered. Therefore, up to 10 design options are introduced. The corresponding analytical models of signaling overhead, delay and UE power consumption are also proposed.On the basis of analysis and simulation results, the SI delivery policies for the cases with different arrival rates of SI demands and the number of the base station (BS) beams are also proposed.