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145
MaxProp: Routing for Vehicle-Based Disruption-Tolerant Networks
- In Proc. IEEE INFOCOM
, 2006
"... Abstract — Disruption-tolerant networks (DTNs) attempt to route network messages via intermittently connected nodes. Routing in such environments is difficult because peers have little information about the state of the partitioned network and transfer opportunities between peers are of limited dura ..."
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Cited by 488 (12 self)
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Abstract — Disruption-tolerant networks (DTNs) attempt to route network messages via intermittently connected nodes. Routing in such environments is difficult because peers have little information about the state of the partitioned network and transfer opportunities between peers are of limited duration. In this paper, we propose MaxProp, a protocol for effective routing of DTN messages. MaxProp is based on prioritizing both the schedule of packets transmitted to other peers and the schedule of packets to be dropped. These priorities are based on the path likelihoods to peers according to historical data and also on several complementary mechanisms, including acknowledgments, a head-start for new packets, and lists of previous intermediaries. Our evaluations show that MaxProp performs better than protocols that have access to an oracle that knows the schedule of meetings between peers. Our evaluations are based on 60 days of traces from a real DTN network we have deployed on 30 buses. Our network, called UMassDieselNet, serves a large geographic area between five colleges. We also evaluate MaxProp on simulated topologies and show it performs well in a wide variety of DTN environments. I.
A Survey of Practical Issues in Underwater Networks
- In Proc. ACM WUWNet
, 2006
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An Energy-Efficient Architecture for DTN Throwboxes
- In Proc. IEEE Infocom
, 2007
"... Abstract—Disruption Tolerant Networks rely on intermittent contacts between mobile nodes to deliver packets using storecarry-and-forward paradigm. The key to improving performance in DTNs is to engineer a greater number of transfer opportunities. We earlier proposed the use of throwbox nodes, which ..."
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Cited by 61 (10 self)
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Abstract—Disruption Tolerant Networks rely on intermittent contacts between mobile nodes to deliver packets using storecarry-and-forward paradigm. The key to improving performance in DTNs is to engineer a greater number of transfer opportunities. We earlier proposed the use of throwbox nodes, which are stationary, battery powered nodes with storage and processing, to enhance the capacity of DTNs. However, the use of throwboxes without efficient power management is minimally effective. If the nodes are too liberal with their energy consumption, they will fail prematurely. However if they are too conservative, they may miss important transfer opportunities, hence increasing lifetime without improving performance. In this paper, we present a hardware and software architecture for energy efficient throwboxes in DTNs. We propose a hardware platform that uses a multi-tiered, multi-radio, scalable, solar powered platform. The throwbox employs an approximate heuristic for solving the NP-Hard problem of meeting an average power constraint while maximizing the number of bytes forwarded by it. We built and deployed prototype throwboxes in UMassDieselNet – a bus DTN testbed. Through extensive trace-driven simulations and prototype deployment we show that a single throwbox with a 270 cm 2 solar panel can run perpetually while improving packet delivery by 37 % and reducing message delivery latency by at least 10 % in the network.
Controlled sink mobility for prolonging wireless sensor networks lifetime
, 2008
"... This paper demonstrates the advantages of using controlled mobility in wireless sensor networks (WSNs) for increasing their lifetime, i.e., the period of time the network is able to provide its intended functionalities. More specifically, for WSNs that comprise a large number of statically placed s ..."
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Cited by 52 (1 self)
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This paper demonstrates the advantages of using controlled mobility in wireless sensor networks (WSNs) for increasing their lifetime, i.e., the period of time the network is able to provide its intended functionalities. More specifically, for WSNs that comprise a large number of statically placed sensor nodes transmitting data to a collection point (the sink), we show that by controlling the sink movements we can obtain remarkable lifetime improvements. In order to determine sink movements, we first define a Mixed Integer Linear Programming (MILP) analytical model whose solution determines those sink routes that maximize network lifetime. Our contribution expands further by defining the first heuristics for controlled sink movements that are fully distributed and localized. Our Greedy Maximum Residual Energy (GMRE) heuristic moves the sink from its current location to a new site as if drawn toward the area where nodes have the highest residual energy. We also introduce a simple distributed mobility scheme (Random Movement or
Theoretical Results on Base Station Movement Problem for Sensor Network
- In Proc. IEEE INFOCOM
, 2008
"... The benefits of using mobile base station to prolong sensor network lifetime have been well recognized. However, due to the complexity of the problem (time-dependent network topology and traffic routing), theoretical performance limit and provably optimal algorithms remain difficult to develop. This ..."
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Cited by 46 (5 self)
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The benefits of using mobile base station to prolong sensor network lifetime have been well recognized. However, due to the complexity of the problem (time-dependent network topology and traffic routing), theoretical performance limit and provably optimal algorithms remain difficult to develop. This paper fills this important gap by contributing theoretical results regarding the optimal movement of a mobile base station. Our main result hinges upon a novel transformation of the joint base station movement and flow routing problem from time domain to space domain. Based on this transformation, we first show if the base station is allowed to be present only on a set of pre-defined points, then we can find the optimal time duration for the base station on each of these points so that the overall network lifetime is maximized. Based on this finding, we show that when the location of the base station is un-constrained (i.e., can move to any point in the two-dimensional plane), we can develop an approximation algorithm for the joint mobile base station location and flow routing problem such that the network lifetime is guaranteed to be at least of the maximum network lifetime, where can be made arbitrarily small depending on required precision.
Decentralized Stochastic Control of Delay Tolerant Networks
"... Abstract—We study in this paper optimal stochastic control issues in delay tolerant networks. We first derive the structure of optimal 2-hop forwarding policies. In order to be implemented, such policies require the knowledge of some system parameters such as the number of mobiles or the rate of con ..."
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Cited by 37 (12 self)
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Abstract—We study in this paper optimal stochastic control issues in delay tolerant networks. We first derive the structure of optimal 2-hop forwarding policies. In order to be implemented, such policies require the knowledge of some system parameters such as the number of mobiles or the rate of contacts between mobiles, but these could be unknown at system design time or may change over time. To address this problem, we design adaptive policies combining estimation and control that achieve optimal performance in spite of the lack of information. We then study interactions that may occur in the presence of several competing classes of mobiles and formulate this as a cost-coupled stochastic game. We show that this game has a unique Nash equilibrium such that each class adopts the optimal forwarding policy determined for the single class problem.
Optimal Monotone Forwarding Policies in Delay Tolerant . . .
, 2008
"... We study in this paper fluid approximations for a class of monotone relay policies in delay tolerant ad-hoc networks. This class includes the epidemic routing and the two-hops routing protocols. We enhance the relay policies with a probabilistic forwarding feature where a message is forwarded to a r ..."
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Cited by 36 (17 self)
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We study in this paper fluid approximations for a class of monotone relay policies in delay tolerant ad-hoc networks. This class includes the epidemic routing and the two-hops routing protocols. We enhance the relay policies with a probabilistic forwarding feature where a message is forwarded to a relay with some probability p. We formulate an optimal control problem where a tradeoff between delay and energy consumption is captured and optimized. We compute both the optimal static value of p as well as the optimal time dependent value of p. We show that the time dependent problem is optimized by threshold type policies and we compute explicitly the value of the optimal threshold for some special cases of relay policies.
Mobility-Sensitive Topology Control in Mobile Ad Hoc Networks
- Proc. IEEE Int’l Parallel and Distributed Processing Symp
, 2004
"... Abstract—In most existing localized topology control protocols for mobile ad hoc networks (MANETs), each node selects a few logical neighbors based on location information and uses a small transmission range to cover those logical neighbors. Transmission range reduction conserves energy and bandwidt ..."
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Cited by 34 (7 self)
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Abstract—In most existing localized topology control protocols for mobile ad hoc networks (MANETs), each node selects a few logical neighbors based on location information and uses a small transmission range to cover those logical neighbors. Transmission range reduction conserves energy and bandwidth consumption, while still maintaining network connectivity. However, the majority of these approaches assume a static network without mobility. In a mobile environment network connectivity can be compromised by two types of “bad ” location information: inconsistent information, which makes a node select too few logical neighbors, and outdated information, which makes a node use too small a transmission range. In this paper, we first show some issues in existing topology control. Then, we propose a mobility-sensitive topology control method that extends many existing mobility-insensitive protocols. Two mechanisms are introduced: consistent local views that avoid inconsistent information and delay and mobility management that tolerate outdated information. The effectiveness of the proposed approach is confirmed through an extensive simulation study. Index Terms—Connectivity, mobile ad hoc networks (MANETs), mobility management, simulation, topology control, view consistency. æ 1
Routing Strategies for Delay-Tolerant Networks
"... Delay-Tolerant Networks (DTNs) have the potential to interconnect devices in regions that current networking technology cannot reach. The idea is that an end-to-end connection may never be present. To make communication possible, intermediate nodes take custody of the data being transferred and forw ..."
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Cited by 34 (0 self)
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Delay-Tolerant Networks (DTNs) have the potential to interconnect devices in regions that current networking technology cannot reach. The idea is that an end-to-end connection may never be present. To make communication possible, intermediate nodes take custody of the data being transferred and forward it as the opportunity arises. Both links and nodes may be inherently unreliable and disconnections may be long-lived. To realize the DTN vision, routes must be found over multiple unreliable, intermittently-connected hops. Many researchers have investigated this fundamental challenge, particularly over the past five years. This paper surveys the area of routing in delay-tolerant networks and presents a system for classifying the proposed routing strategies.
A Hybrid Routing Approach for Opportunistic Networks
- In Proc. of ACM SIGCOMM Workshop on Challenged Networks
, 2006
"... With wireless networking technologies extending into the fabrics of our working and operating environments, proper handling of intermittent wireless connectivity and network disruptions is of significance. As the sheer number of potential opportunistic application continues to surge (i.e. wireless s ..."
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Cited by 32 (7 self)
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With wireless networking technologies extending into the fabrics of our working and operating environments, proper handling of intermittent wireless connectivity and network disruptions is of significance. As the sheer number of potential opportunistic application continues to surge (i.e. wireless sensor networks, underwater sensor networks, pocket switched networks, transportation networks, and etc.), the design for an effective routing scheme that considers and accommodates the various intricate behaviors observed in an opportunistic network is of interest and remained desirable. While previous solutions use either replication or coding techniques to address the challenges in opportunistic networks, the tradeoff of these two techniques only make them ideal under certain network scenarios. In this paper, we propose a hybrid scheme, named H-EC, to deal with a wide variety of opportunistic network cases. H-EC is designed to fully combine the robustness of erasure coding based routing techniques, while preserving the performance advantages of replication techniques. We evaluate H-EC against other similar strategies in terms of delivery ratio and latency, and find that H-EC offers robustness in worst-case delay performance cases while achieving good performance in small delay performance cases. We also discuss the traffic overhead issues associated with H-EC as compared to other schemes, and present several strategies that can potentially alleviate the traffic overhead of H-EC schemes.
