低轨卫星物联网数据传输流程设计

Design of Segmented LEO Satellite IoT Data Transmission Process

低轨卫星物联网是解决全球物联网无缝覆盖的唯一手段,但由于低轨卫星通信信道的特殊性,尤其是在低轨卫星通信过程中动态的星际链路造成不连续性等问题导致现有地面物联网协议并不能简单地应用到低轨卫星物联网中,必须要对现有地面物联网协议进行修改才能满足低轨卫星物联网的应用环境,因此,提出了基于窄带物联网的分段式低轨卫星物联网数据传输流程。该流程采用分段的方式,将终端与基站之间的数据传输与卫星数据下发信关站进入核心网的数据传输过程作为两段,在信关站中设立数据处理网关模拟终端与基站之间的信令交互,从而减少链路不连续造成的时延大的问题。仿真验证了改进后数据传输流程在低轨卫星物联网坏境下的适用性以及在吞吐量、丢包率和传输时延上的改进。

The LEO satellite IoT is the only means to solve the seamless coverage of the global Internet of Things. However,due to the particularity of the LEO satellite communication channel,especially discontinuity caused by dynamic interstellar link in the process of the LEO satellite communication which has resulted in existing ground IoT protocol cannot be simply applied to the LEO satellite IoT,the existing ground IoT protocol must be modified to meet the application environment of LEO satellite IoT.Therefore,the segmental data transmission process of LEO satellite IoT is proposed based on NB-IoT. Adopting a segmentation method,the data transmission process between the UE and eNodeB,and the data transmission process of the satellite data sending the gateway to the core network are taken as two segments,and the data processing gateway is set up in the gateway to simulate the signaling interaction between the UE and the eNodeB,thereby reducing the large delay caused by the discontinuity of the link.The simulation verifies the applicability of the improved data transmission process in the LEO satellite IoT environment and the improvement in throughput,packet loss rate and transmission delay.