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A Novel Onboard-gateway-based Mechanism to Improve TCP Performance in Aeronautical Satellite Networks 总被引:1,自引:1,他引:0
GU Ming ZHANG Jun 《中国航空学报》2007,20(3):260-265
The IP-based networks on aircraft serve to support Internet services via satellites. However, in aeronautical satellite hybrid net- works,the TCP protocol performance often deteriorates due to improper decreases and slow recovery of the congestion window. This paper proposes a window size determination and notification mechanism, onboard-gateway-based mechanism (OGBM), which is based on the onboard gateway in the networks on aircraft. A cross-layer approach is adopted by the onboard gateway to obtain the satellite link bandwidth information. And then, by the gateway, through changing the receiver’s advertised window field in ACK packets, TCP sources are notified of the window size of each TCP source calculated on the ground of bandwidth delay product and flow numbers. The mechanism is able to avoid improper changes of TCP window and serve multiple users. Simulation results show that the mechanism with the fairness index close to 1 improves TCP performance in aeronautical satellite networks. 相似文献
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介绍了欧空局的自动转移飞行器(ATV)的轨道控制方案和技术。给出了ATV的飞行方案、测量敏感器和执行机构的配置,以及在空间站调相段、寻的段、接近段和最终逼近段的轨控策略。 相似文献
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Hongliang Xu Jinling Wang Xingqun Zhan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
Integrity is the ability of Global Navigation Satellite Systems (GNSS) to detect faults in measurements and provide timely warnings to users and operators when the navigation system cannot meet the defined performance standards, which is of great importance for safety of life critical applications. Compared with both Receiver Autonomous Integrity Monitoring (RAIM) and ground based GNSS Integrity Channel (GIC) methods which are widely adopted nowadays, the Satellite Autonomous Integrity Monitoring (SAIM) method can be used to monitor orbit/ephemeris and clock errors, and has advantages in monitoring orbit and clock quality and providing instantaneous responses when faults happen. 相似文献
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