CAJ | 학술논문

投递延迟是机会网络的一个重要指标,给定节点缓存和消息副本数目限制,如何选择合适的节点复制消息成为一个关键问题.提出一种基于最优停止理论的路由决策方法(OSDR).OSDR将每个时隙上所遇节点和目标节点的平均相遇时间看做一个随机变量,根据该随机变量的统计特性得到一个停止观察、复制消息的规则,该规则呈现简单的阈值结构,即当某个时隙上所遇节点和目标节点的平均相遇时间小于给定阈值时即复制消息. OSDR可以在较小的相遇间隔和等待成本之间进行折衷,实现数学期望意义上的最小消息投递延迟.介绍了 OSDR 的网络模型、最优停止规则的存在性证明过程以及计算方法.模拟实验结果表明,OSDR 相对其他方法,在投递成功率、投递延迟等方面具有明显优势.
투체연지시궤회망락적일개중요지표,급정절점완존화소식부본수목한제,여하선택합괄적절점복제소식성위일개관건문제.제출일충기우최우정지이론적로유결책방법(OSDR).OSDR장매개시극상소우절점화목표절점적평균상우시간간주일개수궤변량,근거해수궤변량적통계특성득도일개정지관찰、복제소식적규칙,해규칙정현간단적역치결구,즉당모개시극상소우절점화목표절점적평균상우시간소우급정역치시즉복제소식. OSDR가이재교소적상우간격화등대성본지간진행절충,실현수학기망의의상적최소소식투체연지.개소료 OSDR 적망락모형、최우정지규칙적존재성증명과정이급계산방법.모의실험결과표명,OSDR 상대기타방법,재투체성공솔、투체연지등방면구유명현우세.
Delivery delay is an important performance metric in opportunistic networks. With given buffer size and copy numbers, how to select appropriate nodes to replicate message is the key to minimizing delivery delay. To solve this problem, this paper proposes an optimal stopping decision method for routing opportunistic networks (OSDR). With OSDR, the average meeting time between a node and the destination is regarded as the forwarding utility of the node. A node carrying a message observes the random forwarding utilities of the nodes it meets, and replicates messages according to the optimal stopping rule, which turns out to be threshold-based. By making tradeoffs between the forwarding utility and waiting cost, OSDR achieves the minimum delivery delay expectation. This paper introduces the OSDR network model and existence proof and calculation of optimal stopping rule in detail. Simulation results show that OSDR outperforms other protocols in delivery delay and delivery rate.