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Scaling Properties of Delay Tolerant Networks with Correlated Motion Patterns


Mobile wireless networks with intermittent connectivity, often called Delay/Disruption Tolerant Networks (DTNs), have recently received a lot of attention because of their utility in various application scenarios where delay is noncritical. DTN routing and transport protocols effectively overcome partial connectivity by letting the nodes carry-and-forward data. The scalability of DTN protocols is very important for protocol design and evaluation. In particular, we need models that allow us to predict the performance of DTNs as a function of node mobility behavior (e.g., inter-contact times). Yet so far little work has been done to develop a unified framework that formalizes DTN performance as a function of motion behavior. In this paper, we represent DTNs as a class of wireless mobile networks with intermittent connectivity, where the inter-contact behavior of an arbitrary pair of nodes can be described by a generalized twophase distribution consisting of a power-law head with an exponential tail, which represents correlated node mobility. Recent experiments have confirmed that such a two-phase distribution is a more realistic model for real traces collected from vehicular and pedestrian scenarios than the previous models based on random mobility and Poisson assumptions. Using this DTN model, we make the following contributions. First, we extend the throughput and delay scaling results of Grossglauser and Tse (originally derived for an exponential inter-contact time distribution) to a more general mobility model with a two-phase distribution. Second, we analyze the impact of finite buffer on the capacity scaling properties † This work was done while the author was affiliated with UCLA. ∗This research is supported through participation in the International Technology Alliance sponsored by the U.S. Army Research Laboratory and the U.K. Ministry of Defense under Agreement Number W911NF-06-3-0001, and; by ARMY MURI under funding W911NF0510246. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. CHANTS’09, September 25, 2009, Beijing, China. Copyright 2009 ACM 978-1-60558-741-7/09/09 ...$10.00. of DTNs, again for different correlation behaviors. Finally, we validate our analytical results with a simulation study.

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Information & Date

In ACM MobiCom Workshop on Challenged Networks (Chants 2009), Beijing, China, September. 2009


Uichin Lee
Soon Young Oh
Kang-Won Lee
Mario Gerla