延迟容忍网络中一种基于拥塞程度的端到端确认机制

Congestion level based end-to-end acknowledgement mechanism in delay tolerant networks

端到端传输的可靠性是传输层的重要问题之一,但是由于网络连接的间歇性,延迟可容忍网络(DTN)往往缺乏稳定的端到端路径,这使得传统的端到端可靠性方法无法直接应用在这类网络之中。分析DTN中端到端可靠性机制的基本原理以及存在的主要问题,提出一种新的基于拥塞程度自适应的端到端确认机制,即APR(Active-Passive Receipt),采用主动反馈与被动反馈相结合的方式,根据网络的拥塞状态自适应地调整确认消息的传输方式,限制网络的总体开销,同时保证较合理的传播延时,以求达到较好的综合性能。模拟结果表明:该方法有效地平衡网络开销和延迟性能,并获得较高的消息到达率。

Transport layer end-to-end reliability is one important issue in delay tolerant networks （DTNs）. Because of the intermittent connectivity, DTNs lack stable end-to-end paths. Thus traditional end-to-end reliability approaches cannot work well in DTNs. The principle of end-to-end acknowledgement and the existing main problems in DTNs are analyzed deeply, and a novel congestion level based end-to-end acknowledgement mechanism--active-passive receipt （APR） is proposed, which combines active manner with passive manner in order to limit the total overhead and guarantee a reasonable transmission delay, and ultimately achieve preferable combination property. Simulation results show that our approach effectively balances the network cost and delay, and achieves higher message delivery rate.