Mobile Ad-hoc Networks: Mobility-induced Metrics, Performance Analysis, and System Design

time and space scaling;convex ordering;failure rate;aging property;exponential vs. power-law;mobile ad-hoc network;inter-meeting time distribution

Cai, Han ; Do Young Eun, Committee Chair,Michael Devetsikiotis, Committee Member,Mihail Sichitiu, Committee Member,Min Kang, Committee Member,Cai, Han ; Do Young Eun ; Committee Chair ; Michael Devetsikiotis ; Committee Member ; Mihail Sichitiu ; Committee Member ; Min Kang ; Committee Member

University:North Carolina State University

关键词: time and space scaling;    convex ordering;    failure rate;    aging property;    exponential vs. power-law;    mobile ad-hoc network;    inter-meeting time distribution;   

Others  :  https://repository.lib.ncsu.edu/bitstream/handle/1840.16/5783/etd.pdf?sequence=1&isAllowed=y

美国|英语

来源: null

【 摘 要 】

Mobile Ad-hoc Network (MANET), a type of self-configuring wireless ad-hoc network,comprises of mobile elements equipped with wireless communication devices.The mobility pattern of mobile nodes and the packet forwarding strategy cruciallydecide MANET performance. The node mobility leads to time-varying network topology.Conventional routing schemes fails due to the infeasibility to set up the end-toendpath before data transmission. The mobility pattern affects system performancethrough mobility-induced metrics such as contact time and inter-meeting time. Thesemetrics are critical in determining the MANET performance, as well as choosing variousscheduling/forwarding algorithms.In this dissertation, we study the effect of mobility patterns on the MANET performancethrough the mobility-induced metrics, e.g., inter-meeting time. The intermeetingtime is typically assumed to be exponentially distributed in MANET performancestudies. However, recent empirical results disclose clear power-law behavior ofinter-meeting time distribution. This outright discrepancy potentially undermines ourunderstanding of the performance tradeoffs in MANET obtained under the assumedinter-meeting time with exponential distribution, and thus calls for further study onthe power-law (or more generally, non-exponential) inter-meeting time including itsfundamental cause, mobility modeling, and its effect.We first prove that the finite/infinite domain with respect to the time scale ofinterest critically decides the exponential/power-law tail of the inter-meeting timedistribution. We then show a convex ordering relationship among inter-meeting times of various mobility models indexed by their degrees of correlation, which is in goodagreement with the ordering of network performance under a set of mobility patternswhose inter-meeting time distributions have power-law ‘head’ followed by exponential‘tail’. Finally, we analyze various characteristics of the relative mobility of a randompair of nodes in MANET to show that they produce inter-meeting time with differentaging properties. The aging property allows us to establish for the first time thatthe approach based on exponential inter-meeting time assumption can always underestimateor over-estimate the actual system performance, under stochastic mobilitypatterns with specific aging properties. Our results also provide theoretic guidelineson how to exploit the memory structure toward better design of protocols undergeneral mobility.