Connected dominating sets (CDSs) are probably the most common way of constructing virtual backbones for broadcasting operation in wireless sensor networks. this is because such backbones guarantee to reduce unnecessar...
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ISBN:
(纸本)9780769534343
Connected dominating sets (CDSs) are probably the most common way of constructing virtual backbones for broadcasting operation in wireless sensor networks. this is because such backbones guarantee to reduce unnecessary message transmissions or flooding in the network. In this paper we propose a simple localized algorithm to construct a small-sized CDS. Considering the sensors deployed in the plane, our main idea is based on the computation of convex hulls of sensor nodes (nodes are considered points in the plane) in a localized manner and a simple coloring scheme, which produces a CDS in unit disk graphs whose size is at most 38 * vertical bar MCDS vertical bar where vertical bar MCDS vertical bar is the size of a minimum CDS. To the best of our knowledge, this is a significant improvement over the best published results in the same context [5]. We also analyze grids and trees to compute the exact approximation ratios for the problem. We show that our algorithm produces an optimal CDS if the graph is a tree and in the case of grids the approximation factor is 2.
sensors have been increasingly used for many ubiquitous computing applications such as asset location monitoring, visual surveillance, and human motion tracking. In such applications, it is important to place sensors ...
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ISBN:
(数字)9783540691709
ISBN:
(纸本)9783540691693
sensors have been increasingly used for many ubiquitous computing applications such as asset location monitoring, visual surveillance, and human motion tracking. In such applications, it is important to place sensors such that every point of the target area can be sensed by more than one sensor. Especially, many practical applications require 3-coverage for triangulation, 3D hull building, and etc. Also, in order to extract meaningful information from the data sensed by multiple sensors, those sensors need to be placed not too close to each other-minimum separation requirement. To address the 3-coverage problem withthe minimum separation requirement, this paper proposes two methods, so called, overlaying method and TRE-based method, which complement each other depending on the minimum separation requirement. For these two methods, we also provide mathematical analysis that can clearly guide us when to use the TRE-based method and when to use the overlaying method and also how many sensors are required. To the best of our knowledge, this is the first work that systematically addresses the 3-coverage problem withthe minimum separation requirement.
Channel estimation is an important procedure of coherent demodulation of OFDM system for underwater acoustic communications, by which the system performance is largely restricted. In this paper, the performance of thr...
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ISBN:
(纸本)9781424421077
Channel estimation is an important procedure of coherent demodulation of OFDM system for underwater acoustic communications, by which the system performance is largely restricted. In this paper, the performance of three pilot patterns and their own application conditions are analyzed and compared. According to the simulation and experiment results, it is concluded that scatter pilot pattern is very suitable for OFDM system for underwater acoustic communications. In addition, vector hydrophone is also can be used to improve communication performance via joint processing of pressure and particle velocity.
Routing algorithms play important roles in wireless sensor networks (WSNs). Usually, nodes in a WSN run on battery with limited power. Hence, routing with efficient power consumption is becoming a critical issue for W...
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ISBN:
(纸本)9781424421077
Routing algorithms play important roles in wireless sensor networks (WSNs). Usually, nodes in a WSN run on battery with limited power. Hence, routing with efficient power consumption is becoming a critical issue for WSNs. In this paper, a routing algorithm, referred to as Energy Prediction and Ant Colony Optimization Routing (EPACOR), is proposed. In the EPACOP, when a node needs to deliver data to the sink, ant colony systems are used to establish the route with optimal or sub-optimal power consumption, and meanwhile, learning mechanism is embedded to predict the energy consumption of neighboring nodes when the node chooses a neighboring node added to the route. the EPACOR is compared both withthe MST (Minimal Spanning Tree)-based routing algorithm following the Prim algorithm and withthe Least Energy Tree (LET)-based routing algorithm following the Dijkstra algorithm. Numeric experiment shows that the EPACOR has the best network lifetime among the three while keeping energy consumption in low level.
the cross-regional transitivity problem of key leak exits in the most key management protocols. It's harmful to the security of system. CUT, a new key management protocol in WSN is presented. the results of simula...
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ISBN:
(纸本)9781424421077
the cross-regional transitivity problem of key leak exits in the most key management protocols. It's harmful to the security of system. CUT, a new key management protocol in WSN is presented. the results of simulation show CUT can solve the cross-regional transitivity problem of key leak and is scalable.
Most existing routing protocols on the object detection and tracking in sensor networks concentrates on finding ways to detect and track one or more individual objects, such as people, animals, and vehicles, and not m...
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ISBN:
(纸本)9781424421077
Most existing routing protocols on the object detection and tracking in sensor networks concentrates on finding ways to detect and track one or more individual objects, such as people, animals, and vehicles, and not many protocols have been done on detecting and tracking continuous objects, such as poison gas, biochemical, and chemical liquid. these continuous objects are quite different from the individual objects in that they continuously distributed across a region and usually occupy a large area. Accordingly, they are detected and sensed by many sensor nodes, and their sensing data are redundant and highly correlated. Hence, there need any efficient scheme on collecting and aggregating locally their sensing data and generating the data report. the continuous objects also tend to diffuse, changes in shape, increases the size, even splits into multiple smaller continuous objects, or join together one continuous object. Accordingly, there also need any efficient scheme to manage efficiently the dynamic change of shape of the continuous objects. therefore, we introduce Dynamic Rectangle Zone-based Collaboration Mechanism for detecting, tracking, and monitoring the continuous objects taking into account their properties. One center node in the zone collects and aggregates the sensing data from sensor nodes which detect the continuous object. the dynamic rectangle zone change newly according to dynamic change of the continuous object and the center node is also altered by another node to minimize the energy consumption for collecting the sensing data.
the transmission radius that affects the consumption of energy in WSNs is an important design parameter. In this paper, we define the expected cost of energy as the product of the average hops of packets that sensor n...
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ISBN:
(纸本)9781424421077
the transmission radius that affects the consumption of energy in WSNs is an important design parameter. In this paper, we define the expected cost of energy as the product of the average hops of packets that sensor nodes intend to transmit to sinks and single-transmission energy consumption. We use mathematical methods deriving a constrained programming model by which the optimal transmission radius can be selected to minimum the expected cost of energy while guaranteeing reliability requirements in linear wireless sensor networks where the location of sensor nodes follows one-dimensional Poisson point process. From analysis we can get that the value of transmission radius is related withthe distance between two neighboring sinks, nodes density and path loss exponent. Simulation results are presented to examine our analysis.
the principle of nodes' localization in wireless sensor networks is analyzed. the nodes' distance measure and localization process are described. CC2420 RF module and LPC2138 MCU are used to be the hardware pl...
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ISBN:
(纸本)9781424421077
the principle of nodes' localization in wireless sensor networks is analyzed. the nodes' distance measure and localization process are described. CC2420 RF module and LPC2138 MCU are used to be the hardware platform of nodes on the location experiment. the results of two RSSI-based localization algorithms (Trilateration and Maximum Likelihood Estimation) in Wireless sensor Networks are presented. Simulation model is built by matlab. Location error influenced by distance measure error and network connectivity is analyzed.
Existing secure network reprogramming protocols for wireless sensor networks (WSNs) target the efficient authentication of code packets, but none of them provide the verification of control packets which are vulnerabl...
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ISBN:
(纸本)9781424421077
Existing secure network reprogramming protocols for wireless sensor networks (WSNs) target the efficient authentication of code packets, but none of them provide the verification of control packets which are vulnerable to Denial of Service (DoS) attacks. In this paper, we propose the secure and DoS-resistant network reprogramming scheme based on CPK (Combined Public Key) that can verify control packets so that external attackers can not exploit the Deluge epidemic and suppression mechanisms to launch DoS attacks. Simulation shows that the proposed scheme adds only a modest amount of overhead to existing secure network reprogramming schemes, and is therefore feasible and practical in WSNs.
Estimating the reliability and lifetime distribution of wireless sensor network is very useful in various applications. this problem is known to be NP-hard. In this paper, we present a hexagon tessellation sensor netw...
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ISBN:
(纸本)9781424421077
Estimating the reliability and lifetime distribution of wireless sensor network is very useful in various applications. this problem is known to be NP-hard. In this paper, we present a hexagon tessellation sensor network model with role assignment scheme and estimate the reliability and lifetime distribution by employing a new improved Monte Carlo scheme which incorporates both simulation and analytic methods and is suitable for the WSN. the simulation results show that the role assignment scheme and node density have important effects on the network reliability and lifetime by analyzing the node probability distribution in different situation.
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