Research And Simulations Of Resource Allocation And Transmission Protocol In Satellite Networks

With the rapid development of communication technologies in recent years,the satellite systems have gained the characteristics of high-speed information exchange,global coverage and high quality communication,making it a hot research topic in many countries.At the same time,with the explosion of people's demand for information exchange,the ground communication network fails to enable global seamless coverage in future communications.Consequently,it is significantly important to study and build the satellite communication system.This thesis focuses on satellite communication network system,and mainly studies spot-beam communication resource allocation and network transmission protocol.A resource allocation algorithm based on the service classification model and a communication protocol based on the Genetic Algorithm have been designed for satellite networks,both of which are respectively verified by simulation.Furthermore,the thesis establishes a simulation platform for satellite communication networks.Firstly,this thesis studies the service types and communication service requirements in satellite communication scenarios,and sorts out the communication resources and network status of the satellite system,such as beam,bandwidth and power.A service classification model based on communication service requirements has been introduced,and a communication resource allocation algorithm for satellite system based on Genetic Algorithm has been designed.The algorithm is implemented and simulated on MATLAB platform,with the comparison the existing algorithm.Secondly,the thesis studies the communication protocol for satellite network,and analyzes the limitations of utilizing ground communication protocols in satellite networks and the extension to these protocols.A satellite network communication and transmission protocols also designed in this thesis,capable of distinguishing the reason of packet loss between bit error and network congestion,and dynamically adjusting network parameters accordingly.NS-2 simulation platform has been used to simulate the network performance of the designed protocol.The thesis compares it with existing protocols in terms of link throughput,packet loss rate and transmission delay.Finally,the thesis designs and establishes a satellite network communication simulation platform based on OPNET platform.The simulation process is designed,the simulating satellite network is built,and the functions of nodes such as satellite and network control center are realized the platform.Besides the satellite communication resource allocation algorithm and the satellite network communication protocol are deployed on the platform for performance verification.A prototype user interface for the satellite network simulation platform is also developed to facilitate the user to operate the platform.