Research Of MAC Layer Protocol On Satellite Side In Satellite Iot System

With the arrival of 5G,the Internet of Things has become a popular topic.How to provide communication service for large number of IoT terminals has become a reserch hotspot.5G has given the solution to deploy communication network for the Internet of Things on the basis of the terrestrial network.The coverage of terrestrial network is achieved by building base stations,which is limited by geographical factors.And the base stations will be destroyed in natrual disasters.In order to cover the remote areas such as ocean,desert and forest,and to provide all-weather,anti-destructive communication service,many countries are building satellite IoT systems.Communication between satellites and terminals in satellite IoT systems needs supporting of matched protocol.This paper reserches on MAC layer protocol on satellite side in satellite IoT system.And this paper focuses on multiple access method,and proposes a novel method.Then a MAC layer protocol on satellite side is designed and implimented in combination with the proposed access method.At first,this paper irnvestigates and analyzes the characteristics of the satellite IoT system and the research status of satellite IoT multiple access technology in recent years.Then,the multiple access technology using cooperation between multi-receiver is deeply studied.Combined with the multi-satellite characteristics of satellite IoT system,a cooperative slotted ALOHA with reservation for multi-receiver satelite IoT system is proposed.The principle and mechanism of the proposed multiple access method are elaborated by constructing the system model.Then,the performance of the algorithm is theoretically analyzed,and finally the MATLAB simulation is used to compare the performance of the proposed algorithm with the existing algorithms.The simulation results show that the proposed multiple access method can effectively solve the collision problem of ALOHA in multi-satellite systems,and it outperforms the comparison algorithm in terms of throughput and packet loss ratio.Then,combined with the multiple access algorithm proposed in this paper,the functional modules of MAC layer protocol on satellite side are designed.And the protocol architecture and interface are designed in combination with the inter-layer interaction of the protocol.Finally,the protocol is implemented in C language programming on Windows OS,and the designed protocol is verified.The running results show that the designed MAC layer protocol can operate correctly.