Research On Network AQM And Protocol Optimization For Mobile Monitoring

With the development of Internet, various kinds of new applications appear constantly.They all have high requirements to the time delay,throughput,especially strong real-time applications such as mobile monitoring,video calls.The Satellite networks,which is necessary for the mobile monitoring,has many disadvantages such as Asymmetric bandwidth,unstable network,high bit error rate and so on.This is a new challenge to The existing congestion control method.In order to improve the performance of congestion control mechanism,this paper put forward TCP-QS and ASRED from two aspects of the TCP protocol control and intermediate node control.TCP-QS algorithm mainly optimize the slow start stage.At the beginning of the connection,the cwnd is set as a a larger value according to the detected network bandwidth.in which way,the time of the slow start stage is shortened.during the transmission, Adjust the ssthresh dynamically According to the change of network.When packet loss occurs,take different methods According to the different reasonsBasing on the framework of RED,ASRED uses a new function to calculate the discarding probability.In addition, the adaptive adjustment of maxp mechanism is added into the algorithm. Packet loss probability grows in different ways according to the average queue length, in which way ASRED can avoid congestion, and guarantees the full use of bandwidth.the adaptive adjustment of maxp reduce the sensitivity of the parameter Settings and Improve the robustness of the algorithm.the simulation of NS2 network simulation software shows that, TCP- QS algorithm has increased significantly in time complexity and throughput.ASRED algorithm makes the queue length more stable, improves the Bandwidth utilization and reduce the sensitivity to parameters.