Accuracy Enhancement for Contact Graph Routing in Space Delay Tolerant Networks

作者：Shi Wenfeng; Zhou Huachun^*; Gao Deyun

来源：Journal of the China Railway Society, 2017, 39(7): 87-97.

DOI：10.3969/j.issn.1001-8360.2017.07.013

• Accuracy enhancement
• Contact graphs
• Forwarding mechanisms
• Notification mechanism
• Recovery detection
• Transmission protocols
• Unpredictable contact disruption
• Utility based bundle forwarding

Using the preconfigured contact information of space nodes such as the start time, end time and communication rate, CGR (contact graph routing) can calculate a delivery path from the source to destination conveniently. However, this requires high accuracy of contact graph. Due to the complexity of the space network, satellite may suffer node failure and its associated links suffer from the electromagnetic interference frequently and this may lead to unpredictable contact disruption. Bundles sent by the source using the initially configured contact information cannot be transmitted successfully. Furthermore, CGR's failure to consider the impact of queuing delay on the bundles with low TTL may lead to expiration of these bundles in intermediary nodes. To address these issues, proposed a scheme to improve the accuracy of contact graph routing, including contact failure discovery mechanism, contact recovery detection mechanism, contact failure and recovery notification mechanism, contact graph updating mechanism and routing computing mechanism that considers contact failure. At the same time, a utility function based bundle forwarding mechanism was used. Experiments showed that the accuracy enhancement scheme could improve the delivery ratio and reduce delivery delay in the case of unexpected contact disruption.

• 出版日期2017
• 单位北京交通大学