Research On Repair Strategy Of Satellite IoT Mobile Cache System Based On Fault-tolerant Codes

With the rapid development of mobile terminals and network technologies,the IoT technology has attracted wide attention of researchers,and people are expecting the arrival of the Internet of Everything.However,Io T technologies that rely on wireless communication technologies are still difficult to implement in a cross-regional,large-scale and harsh environment.Therefore,the use of satellite networking instead of terrestrial base stations to provide services to IoT terminals is a trend in the development of the IoT.At the same time,with the advent of the era of big data,the types of business and the amount of data contained in the global IoT are exploding,which will bring pressure and challenge s to the storage and processing capabilities of data in the satellite IoT.Aiming at the reliable storage problem of massive data in the satellite IoT,the data is cached to multiple mobile terminals by using the excess or idle storage capacity of the mobile terminal to meet the data collection of any mobile terminal within the satellite coverage and improve the data transmission efficiency.In the satellite IoT,when the mobile terminal is exhausted or leaves the satellite coverage,the failed data needs to be repaired to ensure the integrity and reliability of the stored data.Therefore,fault-tolerant coding has potential application value in the mobile IoT mobile cache system.Traditional fault-tolerant coding schemes such as copy backup,erasure code,and regenerating code have problems in storage,bandwidth cost,and the number of help nodes required for repair.For the application of the above fault-tolerant coding in the satellite IoT mobile cache system,this paper aims to reduce the overall communication power cost of the system and introduce the Adaptive Minimum Storage Regenerating(AMSR)code into the satellite IoT mobile cache system.In order to solve the problem of reliable storage and timely repair of data in the satellite IoT cache system.The main research contents and contributions are as follows:A satellite IoT mobile cache scenario consisting of IoT terminals without communication distance limitation within satellite coverage.According to the characteristics of the AMSR code to help the number of nodes variable,a threshold-based adaptive repair strategy is designed.Firstly,the system model is modeled,and then based on the threshold repair strategy,the power cost formula o f system data collection and repair is derived and the repair t hreshold point is optimized.The simulation results verify that the overall communication power co st can be minimized when the repair process is initiated at the optimal threshold point.For the mobile cache scenario of the Unmanned Aerial Vehicle(UAV)-satellite IoT application with storage distance limitation,the deployment distribution of the terminal device storage node is based on the Poisson point process to establish a system model.System power cost expressions for each fault-tolerant coding scheme,and new evaluation indicators such as system availability and system power consumption are proposed.By finding the fault-tolerant codes scheme,codes parameters and system parameters suitable for the system through simulation,the system needs to have high availability and low power consumption characteristics.