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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.
TACO-DTN: A Time-Aware COntent-based dissemination system for Delay Tolerant Networks
- in Proceedings of the First International Workshop on Mobile Opportunistic Networking (Mobiopp), Puerto Rico
, 2007
"... Content dissemination applications are becoming more and more popular on fixed infrastructure: in this paper we introduce TACO-DTN, a content dissemination system which, by virtue of being time-aware in terms of subscriptions and events, is appropriate for delay tolerant networks, where a number of ..."
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Cited by 31 (1 self)
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Content dissemination applications are becoming more and more popular on fixed infrastructure: in this paper we introduce TACO-DTN, a content dissemination system which, by virtue of being time-aware in terms of subscriptions and events, is appropriate for delay tolerant networks, where a number of nodes act as infostations, enjoying some form of connectivity to the backbone, and other nodes are mobile devices, reachable sometimes only through intermittent connectivity of carriers. Examples of applications benefiting from such a system could be travel information dissemination systems in large cities (exploiting infostations at bus stops) or on highways, advertisements dissemination at specific times, and information dissemination to remote villages. The approach is based on a novel concept of temporal utility of subscriptions and events. The temporal utility is used to govern the routing of the events to the right infostation (i.e., the one reached by the interested subscribers at the right time), avoiding unnecessary information transfer on slow links and the buffer management, in case buffer limitations are an issue. We give a description of our protocol and discuss its validation through simulation.
Optimal Activation and Transmission Control in Delay Tolerant Networks ⋄
"... Abstract—Much research has been devoted to maximize the life time of mobile ad-hoc networks. Life time has often been defined as the time elapsed until the first node is out of battery power. In the context of static networks, this could lead to disconnectivity. In contrast, Delay Tolerant Networks ..."
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Cited by 12 (5 self)
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Abstract—Much research has been devoted to maximize the life time of mobile ad-hoc networks. Life time has often been defined as the time elapsed until the first node is out of battery power. In the context of static networks, this could lead to disconnectivity. In contrast, Delay Tolerant Networks (DTNs) leverage the mobility of relay nodes to compensate for lack of permanent connectivity, and thus enable communication even after some nodes deplete their stored energy. One can thus consider the lifetimes of nodes as some additional parameters that can be controlled to optimize the performance of a DTN. In this paper, we consider two ways in which the energy state of a mobile can be controlled. Both listening and transmission require energy, besides each of these has a different type of effect on the network performance. Therefore we consider a joint optimization problem consisting of: i) activation, which determines when a mobile will turn on in order to receive packets, and ii) transmission control, which regulates the beaconing. The optimal solutions are shown to be of the threshold type. The findings are validated through extensive simulations. Index Terms—Optimal control, fluid models, delay tolerant networks, threshold policies I.
Quantifying Impact of Mobility on Data Availability in Mobile Ad Hoc Networks”, IEEE www.ijsrp.org Journal of Scientific and Research Publications, Volume 3, Issue 11, November 2013 5 ISSN 2250-3153 Transactions on mobile computing, vol. 9, no. 2, Februar
- Baskaran.P received the Bachelor Degree in Computer science and Engineering from Selvam College of Technology, affiliated to Anna University Chennai, India in 2010, Masters degree in Software Engineering at the Anna University, Coimbatore in
, 2013
"... Abstract—In mobile ad hoc networks, there are many applications in which mobile users share information, e.g., collaborative rescue operations at a disaster site and exchange of word-of-mouth information in a shopping mall. For such applications, improving data availability is a significant issue an ..."
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Abstract—In mobile ad hoc networks, there are many applications in which mobile users share information, e.g., collaborative rescue operations at a disaster site and exchange of word-of-mouth information in a shopping mall. For such applications, improving data availability is a significant issue and various studies have been conducted with this aim. However, each of these conventional works assumed a particular mobility model and did not fully investigate the influence of the mobility on the proposed approach. In this paper, we aim to quantify the influences of mobility on data availability from various perspectives. We assume neither specific applications nor specific protocols but we propose and quantify several metrics that affect data availability. We also report results of some experiments that measure the proposed metrics assuming several typical mobility models. Index Terms—Mobile ad hoc networks, data availability, data replication, data diffusion, pervasive computing. Ç
When cars start gossiping
- in Proceedings of the 6th workshop on Middleware for
, 2008
"... ABSTRACT Vehicular ad hoc networks present challenging characteristics, such as very dynamic behavior and sparse connectivity, that need to be taken into account in designing adequate communication support. Gossip-based protocols have recently emerged as an effective approach to providing reliable ..."
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Cited by 5 (0 self)
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ABSTRACT Vehicular ad hoc networks present challenging characteristics, such as very dynamic behavior and sparse connectivity, that need to be taken into account in designing adequate communication support. Gossip-based protocols have recently emerged as an effective approach to providing reliable and efficient communication in this domain. Nonetheless, despite the preliminary encouraging results, to the best of our knowledge, no previous work has systematically analyzed how gossip protocols are affected by the intrinsic characteristics of vehicular networks such as the very specific mobility patterns of vehicles, the relative abundance of memory and computational resources that vehicles offer, and the availability of geographical information through GPS receivers. In this paper, we aim at filling this gap by examining core requirements of vehicular network applications and analyzing the research challenges that gossip-based communication protocols need to address.
Epidemic Models, Algorithms and Protocols in Wireless Sensor and Ad-hoc Networks
"... Sensor networks are composed of a large number of sensing devices, which are equipped with limited computing and radio communication capabilities. They have diverse application areas, ranging from tracking and intrusion detection for security purposes to environment monitoring and traffic and locati ..."
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Cited by 2 (0 self)
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Sensor networks are composed of a large number of sensing devices, which are equipped with limited computing and radio communication capabilities. They have diverse application areas, ranging from tracking and intrusion detection for security purposes to environment monitoring and traffic and location systems. However, with the steady advancements in processor, memory, communication and sensing technology, and a drive towards a
Routing and quality of service . . .
, 2006
"... Wireless networks have become a common means of communication, and their popularity continues to rise as they enable communication in locations and settings where it was previously unfeasible. While promising many advantages, these networks also pose new challenges. The limited radio coverage, unrel ..."
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Cited by 1 (0 self)
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Wireless networks have become a common means of communication, and their popularity continues to rise as they enable communication in locations and settings where it was previously unfeasible. While promising many advantages, these networks also pose new challenges. The limited radio coverage, unreliable nature of the wireless channel, and mobility of network nodes can lead to frequent disruption of communication links, dynamic network topology, variable bandwidth availability, and high channel error rates. These challenges seek novel solutions to allow a growing number of wireless, mobile users to run applications and avail network services in ways similar to that in wired networks. This thesis makes contributions to three research areas related to wireless and disruption tolerant networks: (1) routing and forwarding to enable disruption tolerant communication in intermittently connected networks, (2) analysis of properties of human mobility and their effect on network protocols in disruption tolerant networks, and (3) quality of service mechanisms for wireless and
Scheduling of multi-stream gossip systems
, 2007
"... Many distributed applications are employing gossip-based message dissemination, where the burden of message distribution is placed on recipient nodes. We are concerned with emerg-ing systems (e.g., peer-to-peer designs for RSS dissemination, queries and code propagation in stationary wireless sensor ..."
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Cited by 1 (1 self)
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Many distributed applications are employing gossip-based message dissemination, where the burden of message distribution is placed on recipient nodes. We are concerned with emerg-ing systems (e.g., peer-to-peer designs for RSS dissemination, queries and code propagation in stationary wireless sensor network systems) that are multiple-source, multiple-recipient systems, where each recipient node is interested in all the streams. Default gossip-based ap-proaches tend to treat each stream independently of the others, overloading each node with message overhead summed from all streams. In this thesis, we apply intelligent schedul-ing strategies for gossip forwarding, effectively piggybacking streams atop one another, to address this significant message overhead. Our problem formulation introduces a new con-cept called the “semblance graph” among gossip streams, based on streams’ frequencies. Our solution consists of two new heuristic algorithms to solve the semblance graph prob-lem. Both heuristics are inspired by Minimum Spanning Tree algorithms. Our semblance graph evaluation shows that the performance of these two heuristics is within 3.5 % of the optimal solution. Our distributed systems simulations show that these scheduling strategies
