By Topic

Mobile Ad Hoc and Sensor Systems, 2008. MASS 2008. 5th IEEE International Conference on

Date Sept. 29 2008-Oct. 2 2008

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Displaying Results 1 - 25 of 132
  • Duty cycle control for low-power-listening MAC protocols

    Publication Year: 2008 , Page(s): 497 - 502
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2166 KB) |  | HTML iconHTML  

    Energy efficiency is of the utmost importance in wireless sensor networks. The family of low-power-listening MAC protocols was proposed to reduce one form of energy dissipation-idle listening, a radio state for which the energy consumption cannot be neglected. Low-power-listening (also called channel probing) MAC protocols are characterized by a duty cycle: a node probes the channel every ti s of sleep. A low duty cycle favors receiving nodes because they may sleep for longer periods of time, but at the same time, contention may increase locally, thereby reducing the number of packets that can be sent. We propose a new approach to dynamically control the duty cycle so that the target rate of transmitted packets is reached, while the consumed energy is minimized. Our approach utilizes control theory and adapts it to the control of ti for low-power-listening MAC protocols in wireless sensor networks. Results show that this approach can appropriately adjust ti to the current network conditions. View full abstract»

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  • Node synchronization for minimizing delay and energy consumption in low-power-listening MAC protocols

    Publication Year: 2008 , Page(s): 265 - 274
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4486 KB) |  | HTML iconHTML  

    Low-power-listening MAC protocols were designed to reduce idle listening, a major source of energy consumption in energy starved wireless sensor networks. Low-power-listening is a MAC strategy that allows nodes to sleep for ti s (the ldquointer-listeningrdquo time) when there is no activity concerning them. It follows that a node has to occupy the medium for at least ti s to guarantee that its destination will probe the channel at some point during the transmission. Low-power-listening protocols have evolved with the introduction of new radios, and the most recent contributions propose to interrupt communication between the sender and the receiver after the data packet has been successfully received and acknowledged. This results in significant energy savings because a sending node does not need to send for full ti periods. We propose a new and simple approach to synchronize nodes on a slowly changing routing tree so that energy consumption is further reduced at the sending node, and the delay is considerably less. Our method allows the nodes to use a lower duty cycle, at no cost of overhead in most cases. Simulation and implementation results show that energy consumption can be reduced by a significant factor (dependant on ti) and delay by at least 18%. View full abstract»

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  • Scalable multicast routing in MANETs using sender-initiated multicast meshes

    Publication Year: 2008 , Page(s): 1 - 12
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2958 KB) |  | HTML iconHTML  

    We present Hydra, the first multicast routing protocol for MANETs that establishes a multicast routing structure approximating the set of source-rooted shortest-path trees from multicast sources to receivers, without requiring the dissemination of control packets from each source of a multicast group. Hydra accomplishes this by dynamically electing a core for the mesh of a multicast group among the sources of the group, and aggregating multicast routing state in the nodes participating in multicast meshes, so that only control packets from the core are disseminated towards the receivers of a group. We prove that Hydra establishes correct routes from senders to receivers of a multicast group when multicast state information is aggregated. We also present simulations results illustrating that Hydra attains comparable or higher delivery ratios than ODMRP, but with considerably lower end-to-end delays and far less communication overhead. Results are shown for scenarios using 802.11 and TDMA as the MAC layer protocols. View full abstract»

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  • Assured Forwarding in multi-hop wireless networks

    Publication Year: 2008 , Page(s): 416 - 421
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1617 KB) |  | HTML iconHTML  

    The assured forwarding (AF) service in a differentiated services network offers different levels of forwarding assurance for IP packets. Several studies have proposed to manipulate the contention window size to provide service differentiation in wireless networks. However, since network congestion in multi-hop wireless networks causes packet losses at the link layer, the contention window size based differentiation scheme is not sufficient to provide the AF service. In this paper, we propose a rate control scheme to control load on the shared channel by adjusting sending rate according to the estimated channel state and the amount of AF traffic. We further propose a RTS retry limit adaptation scheme to compensate the rate control scheme when the accurate estimation of the channel state is not easy. Throughout extensive simulations, we show that proposed schemes are effective to differentiate forwarding assurance in multi-hop wireless networks. View full abstract»

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  • Connectivity monitoring in wireless sensor networks

    Publication Year: 2008 , Page(s): 69 - 79
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2895 KB) |  | HTML iconHTML  

    Connectivity monitoring is useful in practical deployment of wireless sensor network. In order to understand the behavior and performance bottleneck, knowledge of the network connectivity is crucial. In this paper, we propose a flexible and efficient connectivity monitoring algorithm (H2CM) that has three components and operates in a divide and conquer manner. The components include hop vector distance based filtering, Bloom filters and signature hashing and are designed to work with different combinations of network and neighbor set sizes. In simulation, communication cost reduction of H2CM compare to maximal compression of neighborhood information varies from 65% to 85% for large networks (> 1000 nodes) and from 40% to 70% for a medium size network (a few hundred nodes). We have also implemented the algorithm in TinyOS and evaluated its performance on a testbed with 34 motes. View full abstract»

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  • Enforcing cooperation in ad hoc networks with unreliable channel

    Publication Year: 2008 , Page(s): 456 - 462
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1468 KB) |  | HTML iconHTML  

    An inherent assumption for packet forwarding in ad hoc networks is that the nodes will cooperate i.e., nodes can rely in each other. Thus, it is extremely important that cooperation is induced and achieved in the network. In this paper, we use game theory to analyze the necessary and sufficient conditions to enforce cooperation enforced, especially when a node cannot perfectly monitor other nodespsila behaviors. We analyze a credit exchange method under a general unreliable channel and show that the packet forwarding probability can be adjusted through proper design of incentives, which in turn can be used to attain the desired Nash Equilibrium. We extend our discussion to repeated games and take several well-known strategy profiles and derive the conditions under which the cooperation can lead to a subgame perfect Nash equilibrium. In particular, we show how the unreliable channel can affect the conditions and how a reputation based strategy leads to subgame perfection even under imperfect monitoring. We further investigate collusion resistance and cooperation coalition formation using evolutionary game theory. Mathematical proofs show the existence of an upper bound on the population share of the non-cooperative nodes for an evolutionarily non-stable strategy that enforces full cooperation. This bound is shown to depend on the nodespsila belief on the continuity of the game. View full abstract»

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  • A low-cost, low-data-rate rapid structural assessment network: Design, implementation, and experimentation

    Publication Year: 2008 , Page(s): 173 - 182
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (7403 KB) |  | HTML iconHTML  

    We present the design, implementation, and experimental evaluation of a wireless sensor network for near real-time structural health monitoring. We use simple custom-built gages to unequivocally detect cracks in critical structural elements. The main data reports have a low data rate and are naturally resilient to loss. We show how a variety of low-cost, off-the-shelf data acquisition/communication devices can be used to support remote monitoring by a control center. The heterogeneous hardware is accommodated by the use of open technology standards, and a software architecture that is portable, modular, and highly configurable. We present an experimental evaluation of our structural assessment network, using a full-scale three-story reinforced concrete building, subjected to lateral forces emulating forces induced by earthquakes. Our results show that a set of 12 strategically positioned sensors on the three floors achieved a zero false-alarm rate, in the sense that each reported breakage can be traced to cracks exceeding the specified total width, and a 100% detection rate for cracks that are covered by a sensor. View full abstract»

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  • Broadcast capacity for wireless ad hoc networks

    Publication Year: 2008 , Page(s): 114 - 123
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2047 KB) |  | HTML iconHTML  

    The capacity of a wireless network has been widely studied in the literature, including the capacity for unicast and the capacity for broadcast. In this paper, we studied the capacity of a wireless network for broadcast. Previous studies on broadcast capacity either assume that all links in the wireless network has the same channel capacity, or assume that the transmission ranges of a wireless node can be arbitrarily large. In this paper we derive analytical upper bounds and lower bounds on broadcast capacity of a wireless network when all nodes in the network has the same bounded transmission power P and all nodes are placed in a square of side-length a. When the fixed data rate channel is used (each node can send W bits/second to nodes within its transmission range if no interference happened), we prove that the broadcast capacity is Theta(W) under the physical interference model. When the Gaussian channel capacity is used, we show that the total broadcast capacity is only Theta((alpharadic(log n/n))-beta) when alpharadic(log n/n) rarr infin. When a alpharadic(log n/n) rarr O(1), we show that the broadcast capacity is Theta(1). We also generalize our results to multicast capacity for physical interference model. View full abstract»

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  • Topology characterization of high density airspace aeronautical ad hoc networks

    Publication Year: 2008 , Page(s): 295 - 304
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5040 KB) |  | HTML iconHTML  

    Aeronautical ad hoc networks represent a special type of ad hoc wireless networks, given their significantly larger scale and the distinct characteristics of their mobile nodes. Aircraft populate the international airspace very heterogeneously. Some regions experience highly dense air traffic, with aircraft headings being largely uncorrelated. Other regions remain only very sparsely populated, with aircraft typically flying parallel to each other. Moreover, the number of airborne aircraft in a given region changes significantly throughout the day. In this paper, we focus on the densely populated European airspace, and investigate the topological behavior of multihop ad hoc wireless networks formed by air-air links of varying communications range. We derive analytical expressions for various topological aspects, such as the lifetime of inter-aircraft links, and the projected hop length using greedy forwarding. These results are in good agreement with the behavior observed in our simulations of the European air traffic scenario. In addition, we assess the performance of greedy forwarding in the aero-nautical environment and show that, under moderate connectivity, this technique delivers almost all packets to their destinations with a minimum hop count. View full abstract»

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  • Distributed roadmap aided routing in sensor networks

    Publication Year: 2008 , Page(s): 347 - 352
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2040 KB) |  | HTML iconHTML  

    Communication between arbitrary pairs of nodes has become critical to support in emerging sensor networking applications. Traditional routing techniques for multi-hop wireless networks either require high control overhead in computing and maintaining routes, or may lead to unbounded route-stretch. In order to bound the route-stretch, we propose a distributed shortest-path roadmap based routing paradigm that embodies two ideas: routing hole approximation that summaries the critical information about hole boundaries and controlled advertisement that advertises the boundary information of each hole within limited neighborhoods. We show that our approach makes a desired tradeoff between the worst case route-stretch and the message overhead through both analysis and simulations. View full abstract»

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  • Performance evaluation of an encountered based multicast scheme for disruption tolerant networks

    Publication Year: 2008 , Page(s): 353 - 358
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2006 KB) |  | HTML iconHTML  

    Some ad hoc network scenarios are characterized by frequent partitions and intermittent connectivity. Hence, existing adhoc routing schemes which assume the existence of end-to-end paths do not work in such challenging networks. Disruption tolerant networking (DTN) technology has been designed for such challenging network environments. Several unicast and multicast routing schemes have been designed for DTNs. However, the existing multicast routing schemes assume a route discovery process that is similar to the existing adhoc network routing approach, and hence will not work well in very sparse network scenarios. Thus, in this paper, we explore an encounter-based multicast routing (EBMR) scheme for DTNs. Our scheme uses fewer hops for message delivery. We present an analytical framework for estimating the delivery performance of the EBMR scheme, and present some analytical and simulation results to show that the EBMR scheme can achieve higher delivery ratio while maintaining high data transmission efficiency compared to other multicast strategies. View full abstract»

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  • Adaptive path accumulation for reactive routing protocols

    Publication Year: 2008 , Page(s): 203 - 212
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3360 KB) |  | HTML iconHTML  

    We study the overhead of some mechanisms for information dissemination. We use reactive routing protocols in mobile ad hoc networks as our illustrative example. However, while reactive routing protocols are the main application for our results, they apply to different settings as well, which include publish/subscribe information dissemination mechanisms, information dissemination in sensor networks, and location services. We use a performance measure, defined in [8], which we call the efficiency xi of the information dissemination process, and use this efficiency to evaluate the overhead. The overhead is influenced by the use of a mechanism to increase the amount of information disseminated, at the cost of a higher overhead, called path accumulation. We compare the overhead of routing protocols with and without path accumulation. We observe that path accumulation is always more efficient at disseminating route information in the network, but the gain in efficiency decreases when it is normalized by the number of extra routes discovered, as more is known about the network. This means that the marginal return of path accumulation decreases over not using path accumulation. We propose a new route discovery mechanism which applies to most of the reactive protocols using a route request/route reply exchange. Our route discovery mechanism, denoted adaptive path accumulation adjusts the accumulated path in order to either: scale its bandwidth overhead down as more information is distributed in the network, or improve the network discovery by carefully selecting the routes to be propagated. We assess a range of adaptive path accumulation policies using numerical evaluation and show the effect of these policies on route discovery and packet overhead. View full abstract»

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  • Using node accountability in credential based routing for mobile ad-hoc networks

    Publication Year: 2008 , Page(s): 503 - 504
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (945 KB) |  | HTML iconHTML  

    This paper propose a secure and efficient routing scheme using a game theoretical approach and trust relationships between the nodes. We assume a ldquoBayesian Gamerdquo model among the nodes to find the optimal behavior of legitimate and malicious nodes. Moreover, using a ldquowatchdogrdquo mechanism and an ldquoacknowledgementrdquo mechanism (ACK), we construct trust relationships between the nodes. View full abstract»

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  • Distributed online data aggregation for large scale sensor networks

    Publication Year: 2008 , Page(s): 153 - 162
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4527 KB) |  | HTML iconHTML  

    To benefit from data aggregation in large scale sensor networks, an aggregation point, i.e. the place where data are aggregated, must be close to sources. In event triggered sensor networks, this can be achieved by dynamically constructing a tree connecting the sources rooted at a nearby node. However, this incurs high control and maintenance overhead. With static trees, the distance (Delta) between sources and the aggregation point can be as high as O(n) where n is the number of nodes in the network. This diminishes the benefit of data aggregation, thereby limiting the scalability of static trees. In this paper we propose AFT (alternative forwarding tree), a structure with multi-level overlapping clusters. Packet forwarding decisions on AFT are made on the fly when packets are being forwarded and it bounds the distance between the aggregation point and sources by O(delta) irrespective of network size, where delta is the diameter of the event. This guarantees that packets can be aggregated near sources without the overhead of constructing a dynamic structure and therefore is scalable. We prove that in the worst case, AFT guarantees aggregation at a node that is at most 2(1 + radic13)delta away from the sources. View full abstract»

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  • A new approach for integrating proactive and reactive routing in MANETs

    Publication Year: 2008 , Page(s): 377 - 383
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1762 KB) |  | HTML iconHTML  

    We propose a new approach to integrate proactive and reactive routing in mobile ad hoc networks. Our work deploys a lightweight proactive algorithm that runs in the background offering a basic routing service, and a reactive algorithm that can be called on demand offering a connection-oriented service. The reactive algorithm uses the routing information from the proactive algorithm in its working, so that there is a synergy between the two parts of the system. An important property of our system is that it allows the choice between proactive and reactive routing to be made for each session individually, by their source nodes. This gives network nodes a very fine-grained level of control over the routing process, and allows them to exploit the complementary properties of proactive and reactive routing, e.g. by matching the choice of the routing approach to the needs of individual sessions. In a range of simulation tests, we evaluate the validity of our approach. View full abstract»

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  • Using directionality in mobile routing

    Publication Year: 2008 , Page(s): 371 - 376
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3289 KB) |  | HTML iconHTML  

    The increased usage of directional methods of communications has prompted research into leveraging directionality in every layer of the network stack. In this paper, we explore the use of directionality in layer 3 to facilitate routing in highly mobile environments. We introduce mobile orthogonal rendezvous routing protocol (MORRP), a lightweight, but scalable routing protocol utilizing directional communications (such as directional antennas or free-space-optical transceivers) to relax information requirements such as coordinate space embedding, node localization, and mobility. This relaxation is done by introducing a novel concept called the directional routing table (DRT) which maps a set-of-IDs to each directional interface to provide probabilistic routing information based on interface direction. We show that MORRP achieves connectivity with high probability even in highly mobile environments while maintaining only probabilistic information about destinations. We also compare MORRP with various proactive, reactive, and position-based routing protocols using single omni-directional interfaces and 8 directional interfaces and show that MORRP gains over 10-14X additional goodput vs. traditional protocols and 15-20% additional goodput vs. traditional protocols using multiple interfaces. View full abstract»

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  • Interference-aware distributed scheduling in TDMA Wireless Mesh Networks

    Publication Year: 2008 , Page(s): 505 - 506
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (633 KB) |  | HTML iconHTML  

    We propose five slot scheduling algorithms for wireless mesh networks (WMNs) using a time division multiple access (TDMA)-based medium access control (MAC) protocol. A preliminary comparative study is carried out through simulation. View full abstract»

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  • An STDMA-based framework for QoS provisioning in wireless mesh networks

    Publication Year: 2008 , Page(s): 223 - 232
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2970 KB) |  | HTML iconHTML  

    Providing strong QoS guarantees for wireless multi-hop networks is very challenging, due to many factors such as use of a shared communication medium, variability in wireless link quality, and so on. However, wireless mesh technology gives the opportunity to alleviate some of these problems, due to lack of mobility in the wireless infrastructure, and presence of natural centralization points in the network. The main contribution of this paper is the definition of a simple framework that exploits these features to provide provable, strong QoS guarantees to network clients. In particular, admitted clients are guaranteed a certain minimum bandwidth and maximum delay on their connections. The framework is based on STDMA scheduling at the MAC layer, which is periodically executed at the network manager to adapt to changes in traffic demand. While scheduling computation is centralized, admission control is performed locally at the wireless backbone nodes, thus reducing signaling. We propose two bandwidth distribution and related admission control policies, which are at opposite ends of the network utilization/spatial fairness trade-off. Through extensive simulations, we show that the proposed framework achieves its design goals of providing strong QoS guarantees to VoIP clients while not sacrificing throughput in a realistic mesh network scenario, also in presence of highly unbalanced load at the backbone nodes. To the best of our knowledge, this is the first proposal with similar features for wireless mesh networks. View full abstract»

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  • Efficient monitoring in wireless mesh networks: Overheads and accuracy trade-offs

    Publication Year: 2008 , Page(s): 13 - 23
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3415 KB) |  | HTML iconHTML  

    802.11-based multi-hop wireless mesh networks have become increasingly prevalent over the last few years. Recently, a lot of focus has been on deploying monitoring frameworks for enterprise and municipal multi-hop wireless networks. A lot of work has also been done on developing measurement-based schemes for resource management and fault management in these networks. The above goals require an efficient monitoring infrastructure to be deployed in the wireless network, which can provide the maximum amount of information regarding the network status, while utilizing the least possible amount of network resources. However, network monitoring introduces overheads, which can impact network performance, from the perspective of the end user. The impact of monitoring overheads on data traffic has been overlooked in most of the previous works. It remains unclear, as to how parameters such as number of monitoring agents, frequency of reporting monitoring data, and others, impact the performance of a wireless network. In this work, we first evaluate the impact of monitoring overheads on data traffic, and show that even small amounts of overheads can cause large degradation in network performance. We then explore several different techniques for reducing monitoring overheads, while maintaining the objective (resource management, fault management and others) that needs to be achieved. Via extensive simulations, we investigate whether a monitoring framework, which is constrained in terms of number of monitors or periodicity of monitoring, can achieve similar performance as a monitoring framework spanning the entire network. We show that different techniques lend themselves to different application scenarios, and evaluate the trade-offs involved in terms of monitoring overheads and quality of monitoring data. View full abstract»

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  • Achieving throughput fairness in Wireless Mesh Networks based on IEEE 802.11

    Publication Year: 2008 , Page(s): 507 - 508
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (628 KB) |  | HTML iconHTML  

    We propose a fair bandwidth allocation scheme for multi-radio multi-channel wireless mesh networks (WMNs) using distributed algorithm. Through an extensive simulation, we show that our scheme ensures per node fairness without loss of the total aggregate throughput. View full abstract»

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  • A scalable hybrid routing architecture with Off-Network Control Processing for very large sensor networks

    Publication Year: 2008 , Page(s): 390 - 395
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4029 KB) |  | HTML iconHTML  

    This paper presents a novel architectural solution to address the problem of scalable routing in very large sensor networks. We develop a routing solution off-network control processing (ONCP) that achieves control scalability in large sensor networks by shifting certain amount of routing functions to an ldquooff-networkrdquo server. A tiered and hybrid routing approach, consisting of ldquocoarse grainrdquo global routing, and distributed ldquofine grainrdquo local routing is proposed for achieving scalability by avoiding network wide control message dissemination. We present the ONCP architectural concepts and analytically characterize its performance in relations to both flat and hierarchical sensor routing architectures. We also show ns2 based experimental results indicating that for large sensor networks with realistic data models, the packet drop, latency and energy performance of ONCP can be significantly better than those for flat and cluster-based protocols. View full abstract»

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  • Coverage planning of Wireless Sensors for mobile target detection

    Publication Year: 2008 , Page(s): 48 - 57
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2432 KB) |  | HTML iconHTML  

    We consider surveillance applications through wireless sensor networks (WSNs) with fully accessible areas to be monitored. In this context, the WSN topology can be planned a priori to maximize application efficiency. We propose an optimization framework for selecting the positions of wireless sensors to detect mobile targets traversing a given area. By leveraging the concept of exposure as a measure of coverage quality, we propose two problem versions: the minimization of the sensors installation cost while guaranteeing a minimum exposure, and the maximization of the exposure of the least exposed path subject to a budget on the sensors installation cost. We present compact mixed integer-linear programming formulations for these problems that can be solved to optimality for reasonable-sized network instances. Moreover, we develop a heuristic that is able to provide near-optimal solutions of the same instances in short computing time and also to tackle large size instances. View full abstract»

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  • SpyMon: Hidden network monitoring for security in wireless sensor Networks

    Publication Year: 2008 , Page(s): 328 - 333
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1689 KB) |  | HTML iconHTML  

    Network monitoring is a basic component for intrusion detection and also an energy-expensive task. However in the existing works the contradiction between energy efficiency and security of network monitoring isnpsilat well handled. In this paper, we propose SpyMon, a network monitoring mechanism for the sensor network. To achieve energy-efficiency and reliability, a subset of sensor nodes are randomly selected as monitors in the network and each sensor node is monitored by at least k nodes. For the resistance against the attacks, the monitors are protected from identity exposure to prevent them becoming the explicit targets of adversaries. A collective monitoring triggering scheme is also proposed to further improve the capability and reliability of monitoring. Our analysis shows that SpyMon is resilient against node compromise while attaining energy efficiency. View full abstract»

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  • Improving QoS under lossy channels through adaptive redundancy

    Publication Year: 2008 , Page(s): 509 - 510
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1333 KB) |  | HTML iconHTML  

    Quality of service (QoS) of a network-wide broadcast (NWB) protocol is one of the most important performance metrics, especially in mobile ad hoc networks, where channel conditions and network topology change frequently. We propose a mesh networking inspired approach to overcome the performance degradation caused by lossy channels. We show that our adaptive approach, whereby the amount of redundancy is adjusted to the current link conditions, can achieve good performance while simultaneously reducing unnecessary energy dissipation. View full abstract»

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  • AS-MAC: An asynchronous scheduled MAC protocol for wireless sensor networks

    Publication Year: 2008 , Page(s): 434 - 441
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3583 KB) |  | HTML iconHTML  

    Energy efficiency of the MAC protocol is a key design factor for wireless sensor networks (WSNs). Due to the importance of the problem, a number of energy efficient MAC protocols have been developed for WSNs. Preamble-sampling based MAC protocols (e.g., B-MAC and X-MAC) have overheads due to their preambles, and are inefficient at large wakeup intervals. SCP-MAC, a very energy efficient scheduling MAC protocol, minimizes the preamble by combining preamble sampling and scheduling techniques; however, it does not prevent energy loss due to overhearing; in addition, due to its synchronization procedure, it results in increased contention and delay. In this paper, we present an energy efficient MAC protocol for WSNs that avoids overhearing and reduces contention and delay by asynchronously scheduling the wakeup time of neighboring nodes. To validate our design and analysis, we implement the proposed scheme on the MicaZ platform. Experimental results show that AS-MAC considerably reduces energy consumption, packet loss and delay when compared with SCP-MAC. View full abstract»

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