Research On SCPS-TP Congestion Control In Satellite Communication Network

The advent of the Internet has greatly facilitated people's work and life,and the network has entered a period of rapid development.However,some regions are difficult to be covered by terrestrial networks because of geographical location and terrain environment.In order to build a globally interconnected network architecture,satellite communications are objectively needed to supplement and improve.At first,the emergence and development of satellite communications played an irreplaceable role in military communications and aerospace communications based on national strategic resources,especially in the construction of space and space integration as well as aerospace security.With the improvement of the quality of wireless communication and the increasing number and types of application services,the bandwidth of the current satellite communication network is somewhat deficient,and due to the high bit error rate of satellite communication network,the problem of asymmetric bandwidth has become an important issue that hinders the improvement of the bandwidth utilization of satellite networks.Therefore,how to improve the bandwidth utilization rate of the satellite forward link in this environment has become an issue that people urgently need to solveIn this paper,the SCPS protocol suitable for satellite communication is introduced first,and the SCPS-TP protocol and some improved algorithms are analyzed in detail.Analysis found that the reverse link ACK congestion in SCPS-TP,congestion window lag adjustment and other issues still affect the forward data transmission efficiency.According to the existing problems,this paper proposes a Vegas_pre algorithm that can shield the positive data transmission due to the reverse link congestion.This algorithm adds a new prediction mechanism for the data link status in the forward link.Under the control of the congestion window for the predictive adjustment.Increase the stability of data transmission,and to a certain extent,improve the bandwidth utilization of satellite networks.The data arrival time record part is added into both ends of the sending and receiving ends to obtain the time when the data arrives at the sending end and the time is sent back to the sending end together with the confirmation frame so as to keep only the forward link transmission delay through the difference between the two ends,It is possible to mask some of the factors that the reverse link may affect the efficiency of forward link transmission.On the forward link,the source end adds the storage function of the round-trip delay,and uses the change of multiple transmission delays to accurately adjust the change of the congestion window and reduce the risk of reducing the transmission efficiency due to the large change of the window.The opnet simulation software is used to simulate the improved protocol,and different simulation factors are used to simulate the different factors.The simulation results show that the improved protocol can obtain a better bandwidth utilization rate in this high bit error rate and high delay environment,which is greatly improved compared with the performance of the original protocol.