Xiaoguo Ye

Dynamic channel reservation scheme based on priorities in LEO satellite systems

According to low earth orbit (LEO) satellite systems with users of different levels, a dynamic channel reservation scheme based on priorities is proposed. Dynamic calculation of the thresholds for reserved channels is the key of this strategy. In order to obtain the optimal thresholds, the traffic is predicted based on the high-speed deterministic movement property of LEO satellites firstly. Then, a channel allocation model based on Markov is established. Finally, the solution of the model is obtained based on the genetic algorithm. Without user location, this strategy effectively reduces handover failures and improves channel utilization by adjusting dynamically the thresholds according to traffic conditions. The simulation results show that the systems overall quality of service can be improved by this strategy.

A New TCP Design for Satellite-HAP Networks

In recent years, several new TCP congestion control algorithms have been proposed to improve TCP performance for networks of high bandwidth delay products. Satellite-HAP networks providing high-speed data transmissions (up to 1 Gb/s). This article aims to show that the proposed new TCP, as a modification of TCPs congestion control mechanism, allows it to achieve reasonable performance in Satellite-HAP networks. In this paper, we implement the performance simulation in NS-2, and the results demonstrate that the proposed new TCP for Satellite-HAP networks has a considerable performance improvement comparing with the other variations of TCP.

The Research of Routing Forwarding Strategies in DTNs Based on Convergence Point

DTN is developed as an emerging network technology which is mainly used in network with long waiting time, intermittent connectivity, and other extreme environments network. It has be favored in the military, transportation, marine monitoring, wildlife tracking, satellites communications and have been applied in some aspects. Currently, there is a lot of research about the DTN. The study includes three hot issues: the routing nodes, DTN-based mobility model and the data distribution and retrieval. To better solve the problem of data distribution and retrieval in DTN, an improved routing algorithm is proposed in this paper.