Results 1 - 10 of 169

Approximate aggregation techniques for sensor databases

by Jeffrey Considine, Feifei Li, George Kollios, John Byers - In ICDE , 2004
"... In the emerging area of sensor-based systems, a significant challenge is to develop scalable, fault-tolerant methods to extract useful information from the data the sensors collect. An approach to this data management problem is the use of sensor database systems, exemplified by TinyDB and Cougar, w ..."
Abstract - Cited by 301 (6 self) - Add to MetaCart
In the emerging area of sensor-based systems, a significant challenge is to develop scalable, fault-tolerant methods to extract useful information from the data the sensors collect. An approach to this data management problem is the use of sensor database systems, exemplified by TinyDB and Cougar, which allow users to perform aggregation queries such as MIN, COUNT and AVG on a sensor network. Due to power and range constraints, centralized approaches are generally impractical, so most systems use in-network aggregation to reduce network traffic. Also, aggregation strategies must provide fault-tolerance to address the issues of packet loss and node failures inherent in such a system. An unfortunate consequence of standard methods is that they typically introduce duplicate values, which must be accounted for to compute aggregates correctly. Another consequence of loss in the network is that exact aggregation is not possible in general. With this in mind, we investigate the use of approximate in-network aggregation using small sketches. Our contributions are as follows: 1) we generalize well known duplicateinsensitive sketches for approximating COUNT to handle SUM (and by extension, AVG and other aggregates), 2) we present and analyze methods for using sketches to produce accurate results with low communication and computation overhead (even on low-powered CPUs with little storage and no floating point operations), and 3) we present an extensive experimental validation of our methods. 1
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VBF: Vector-Based Forwarding Protocol for Underwater Sensor Networks

by Peng Xie, Jun-hong Cui, Li Lao - In Proc. of IFIP Networking , 2005
"... Underwater Sensor Networks (UWSNs) are significantly different from land-based sensor networks. In UWSNs, the new features: low bandwidth, high latency, high network dynamics, high error probability, and 3-dimensional space, bring big challenges to network protocol design. In this technical report ..."
Abstract - Cited by 80 (20 self) - Add to MetaCart
Underwater Sensor Networks (UWSNs) are significantly different from land-based sensor networks. In UWSNs, the new features: low bandwidth, high latency, high network dynamics, high error probability, and 3-dimensional space, bring big challenges to network protocol design. In this technical report, we tackle one fundamental problem in UWSNs: scalable and energy efficient routing. We propose a novel routing protocol, called vector-based forwarding (VBF) to address these new challenges. VBF is scalable and energy efficient. In VBF, no state information is required on the sensor nodes and only a small fraction of the nodes are involved in routing. Moreover, we develop a localized and distributed self-adaptation algorithm to enhance the performance of VBF. The self-adaptation algorithm allows the nodes to weigh the benefit to forward packets and reduce energy consumption by discarding the low benefit packets. We evaluate the performance of VBF through extensive simulations. Our experiment results show that for networks with small or medium node mobility (2 m/s-10 m/s), VBF can effectively accomplish the goals of energy efficiency, high success of data delivery and low end-to-end delay.
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The holes problem in wireless sensor networks: A survey

by Nadeem Ahmed, Salil S. Kanhere Sanjay Jha - ACM Sigmobile Mobile Computing and Communication Review
"... Several anomalies can occur in wireless sensor networks that impair their desired function-alities i.e., sensing and communication. Different kinds of holes can form in such networks creating geographically correlated problem areas such as coverage holes, routing holes, jamming holes, sink/black hol ..."
Abstract - Cited by 65 (1 self) - Add to MetaCart
Several anomalies can occur in wireless sensor networks that impair their desired function-alities i.e., sensing and communication. Different kinds of holes can form in such networks creating geographically correlated problem areas such as coverage holes, routing holes, jamming holes, sink/black holes and worm holes, etc. We detail in this paper different types of holes, discuss their characteristics and study their effects on successful working of a sensor network. We present state-of-the-art in research for addressing the holes related problems in wireless sensor networks and discuss the relative strengths and short-comings of the proposed solutions for combating different kinds of holes. We conclude by highlight-ing future research directions. I.
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Toward resilient security in wireless sensor networks

by Hao Yang, Yuan Yuan, Songwu Lu, William Arbaugh - in MobiHoc ’05: Proceedings of the 6th ACM international symposium on Mobile , 2005
"... Node compromise poses severe security threats in wireless sensor networks. Unfortunately, existing security designs can address only a small, fixed threshold number of compromised nodes; the security protection completely breaks down when the threshold is exceeded. In this paper, we seek to overcome ..."
Abstract - Cited by 46 (1 self) - Add to MetaCart
Node compromise poses severe security threats in wireless sensor networks. Unfortunately, existing security designs can address only a small, fixed threshold number of compromised nodes; the security protection completely breaks down when the threshold is exceeded. In this paper, we seek to overcome the threshold limitation and achieve resiliency against an increasing number of compromised nodes. To this end, we propose a novel location-based approach in which the secret keys are bound to geographic locations, and each node stores a few keys based on its own location. The location-binding property constrains the scope for which individual keys can be (mis)used, thus limiting the damages caused by a collection of compromised nodes. We illustrate this approach through the problem of report fabrication attacks, in which the compromised nodes forge non-existent events. We evaluate our design through extensive analysis, implementation and simulations, and demonstrate its graceful performance degradation in the presence of an increasing number of compromised nodes.

ROMER: Resilient opportunistic mesh routing for wireless mesh networks

by Yuan Yuan, Hao Yang, Starsky H. Y. Wong, Songwu Lu, William Arbaugh - in The 1st IEEE Workshop on Wireless Mesh Networks (WiMesh , 2005
"... Abstract — Wireless mesh networks hold promises to provide robust and high-throughput data delivery to wireless users. In a mesh network, high-speed Access Points (HAPs), equipped with advanced antennas, communicate with each other over wireless channels and form an indoor/outdoor broadband backhaul ..."
Abstract - Cited by 44 (1 self) - Add to MetaCart
Abstract — Wireless mesh networks hold promises to provide robust and high-throughput data delivery to wireless users. In a mesh network, high-speed Access Points (HAPs), equipped with advanced antennas, communicate with each other over wireless channels and form an indoor/outdoor broadband backhaul. This backbone efficiently forwards user traffic to a few gateway APs (GAPs), which additionally have high-speed connections to the wired Internet. In this paper, we describe ROMER, a resilient and opportunistic routing solution for mesh networks. ROMER balances between long-term route stability and shortterm opportunistic performance. It builds a runtime, forwarding mesh on a per-packet basis that offers a set of candidate routes. The actual forwarding path by each packet opportunistically adapts to the dynamic channel condition and exploits the highestrate wireless channels at the time. To improve resilience against lossy links, HAP failures or HAPs under DoS attacks, ROMER delivers redundant data copies in a controlled and randomized manner over the candidate forwarding mesh. We evaluate the effectiveness of ROMER through both simulations and analysis. I.
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DBR: Depth-Based Routing for Underwater Sensor Networks

by Hai Yan, Zhijie Jerry Shi, Jun-hong Cui
"... Abstract. Providing scalable and efficient routing services in underwater sensor networks (UWSNs) is very challenging due to the unique characteristics of UWSNs. Firstly, UWSNs often employ acoustic channels for communications because radio signals do not work well in water. Compared with radio-freq ..."
Abstract - Cited by 40 (2 self) - Add to MetaCart
Abstract. Providing scalable and efficient routing services in underwater sensor networks (UWSNs) is very challenging due to the unique characteristics of UWSNs. Firstly, UWSNs often employ acoustic channels for communications because radio signals do not work well in water. Compared with radio-frequency channels, acoustic channels feature much lower bandwidths and several orders of magnitudes longer propagation delays. Secondly, UWSNs usually have very dynamic topology as sensors move passively with water currents. Some routing protocols have been proposed to address the challenging problem in UWSNs. However, most of them assume that the full-dimensional location information of all sensor nodes in a network is known in prior through a localization process, which is yet another challenging issue to be solved in UWSNs. In this paper, we propose a depth-based routing (DBR) protocol. DBR does not require full-dimensional location information of sensor nodes. Instead, it needs only local depth information, which can be easily obtained with an inexpensive depth sensor that can be equipped in every underwater sensor node. A key advantage of our protocol is that it can handle network dynamics efficiently without the assistance of a localization service. Moreover, our routing protocol can take advantage of a multiple-sink underwater sensor network architecture without introducing extra cost. We conduct extensive simulations. The results show that DBR can achieve very high packet delivery ratios (at least 95%) for dense networks with only small communication cost. 1
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Defending against path-based DoS attacks in wireless sensor networks

by Jing Deng, Richard Han, Shivakant Mishra - In SASN , 2005
"... Denial of service (DoS) attacks can cause serious damage in resourceconstrained, wireless sensor networks (WSNs). This paper addresses an especially damaging form of DoS attack, called PDoS (Path-based Denial of Service). In a PDoS attack, an adversary overwhelms sensor nodes a long distance away by ..."
Abstract - Cited by 32 (0 self) - Add to MetaCart
Denial of service (DoS) attacks can cause serious damage in resourceconstrained, wireless sensor networks (WSNs). This paper addresses an especially damaging form of DoS attack, called PDoS (Path-based Denial of Service). In a PDoS attack, an adversary overwhelms sensor nodes a long distance away by flooding a multihop end-to-end communication path with either replayed packets or injected spurious packets. This paper proposes a solution using one-way hash chains to protect end-to-end communications in WSNs against PDoS attacks. The proposed solution is lightweight, tolerates bursty packet losses, and can easily be implemented in modern WSNs. The paper reports on performance measured from a prototype implementation. 1.
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Directed flood-routing framework for wireless sensor networks

by Miklós Maróti - In Proceedings of the 5th ACM/IFIP/USENIX International Conference on Middleware , 2004
"... Abstract. The directed flood-routing framework (DFRF) for wireless sensor networks is introduced in this paper that allows the modeling and rapid development of application specific routing protocols based on directed flooding. Flood-routing protocols are probabilistic methods that make only the bes ..."
Abstract - Cited by 27 (3 self) - Add to MetaCart
Abstract. The directed flood-routing framework (DFRF) for wireless sensor networks is introduced in this paper that allows the modeling and rapid development of application specific routing protocols based on directed flooding. Flood-routing protocols are probabilistic methods that make only the best effort to route data packets. The presented family of protocols can route regular sized data packets via broadcast messages according to customizable, state machine based routing policies that govern the way intermediate nodes rebroadcast messages. The framework supports automatic data packet aggregation, and allows in-network data packet filtering and alteration. 1
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Selection and navigation of mobile sensor nodes using a sensor network

by Atul Verma, Hemjit Sawant, Jindong Tan - Pervasive and Mobile Computing , 2006
"... Hybrid sensor networks comprise of mobile and static sensor nodes setup for the purpose of collaboratively performing tasks like sensing a phenomenon or monitoring a region. In this paper, we present a novel approach for navigating a mobile sensor node (MSN) through such a hybrid sensor network. The ..."
Abstract - Cited by 25 (0 self) - Add to MetaCart
Hybrid sensor networks comprise of mobile and static sensor nodes setup for the purpose of collaboratively performing tasks like sensing a phenomenon or monitoring a region. In this paper, we present a novel approach for navigating a mobile sensor node (MSN) through such a hybrid sensor network. The static sensor nodes in the sensor network guide the MSN to the phenomenon. One or more MSN’s are selected based on their proximity to the detected phenomenon. Navigation is accomplished using the concepts of credit based field setup and navigation force from static sensor nodes. Our approach does not require any prior maps of the environment thus, cutting down the cost of the overall system. The simulation results have verified the effectiveness of the proposed approach. In each of the simulation runs, the static sensor nodes were able to successfully guide the MSN towards the phenomenon 1
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Multirate anypath routing in wireless mesh networks

by Rafael Laufer, Leonard Kleinrock - in INFOCOM 2009, IEEE. IEEE, 2009
"... Abstract—In this paper, we present a new routing paradigm that generalizes opportunistic routing in wireless mesh networks. In multirate anypath routing, each node uses both a set of next hops and a selected transmission rate to reach a destination. Using this rate, a packet is broadcast to the node ..."
Abstract - Cited by 21 (1 self) - Add to MetaCart
Abstract—In this paper, we present a new routing paradigm that generalizes opportunistic routing in wireless mesh networks. In multirate anypath routing, each node uses both a set of next hops and a selected transmission rate to reach a destination. Using this rate, a packet is broadcast to the nodes in the set and one of them forwards the packet on to the destination. To date, there is no theory capable of jointly optimizing both the set of next hops and the transmission rate used by each node. We bridge this gap by introducing a polynomial-time algorithm to this problem and provide the proof of its optimality. The proposed algorithm runs in the same running time as regular shortest-path algorithms and is therefore suitable for deployment in link-state routing protocols. We conducted experiments in a 802.11b testbed network, and our results show that multirate anypath routing performs on average 80 % and up to 6.4 times better than anypath routing with a fixed rate of 11 Mbps. If the rate is fixed at 1 Mbps instead, performance improves by up to one order of magnitude. I.