A Joint Optimization Scheme for Hybrid MAC Layer in LEO Satellite Supported IoT

The Internet of Things (IoT) aims to interconnect and converge the physical world and cyberspace. It represents the future of networking, and leads the wave of the third industrial revolution. As IoT applications evolve, more and more regions lacking infrastructures are also experiencing an urgent need to deploy and connect IoT devices into the network. Low earth orbit satellites, due to its wide coverage and relatively low latency, can provide network access for IoT system. In this article, we propose a low-latency heterogeneous network MAC approach for space-earth integrated IoT network, which can significantly reduce network latency, improve system scalability and balance total system load. Specifically, we design a geographic priority time slot allocation strategy which ensures optimal load and latency, besides, we also design a continuous forward time slot allocation strategy, which guarantees data timeliness while reducing the utilization of satellite resources. Then we design three algorithms based on above strategies, which can effectively reduce network latency and balance the satellite resources. The simulation experimental results are consistent with the theoretical results, which embodies the effectiveness of the algorithm.