http://www.eecs.ucf.edu/~dcm/Teaching/COT4810-Spring2011/Literature/SensorNetworksSurvey.pdf

Wireless sensor networks: a survey

http://www.csun.edu/~andrzej/COMP529-S05/papers/Mesh%20Networks%20Survey.pdf

Wireless mesh networks: a survey

In the last years, wireless sensor networks (WSNs) have gained increasing attention from both the research community and actual users. As sensor nodes are generally battery-powered devices, the critical aspects to face concern how to reduce the energy consumption of nodes, so that the network lifetime can be extended to reasonable times. In this paper we first break down the energy consumption for the components of a typical sensor node, and discuss the main directions to energy conservation in WSNs. Then, we present a systematic and comprehensive taxonomy of the energy conservation schemes, which are subsequently discussed in depth. Special attention has been devoted to promising solutions which have not yet obtained a wide attention in the literature, such as techniques for energy efficient data acquisition. Finally we conclude the paper with insights for research directions about energy conservation in WSNs.

/pdf/energy-conservation-in-wireless-sensor-networks-a-survey-1bl7d2obnm.pdf

Energy conservation in wireless sensor networks: A survey

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

Energy harvesting generators are attractive as inexhaustible replacements for batteries in low-power wireless electronic devices and have received increasing research interest in recent years. Ambient motion is one of the main sources of energy for harvesting, and a wide range of motion-powered energy harvesters have been proposed or demonstrated, particularly at the microscale. This paper reviews the principles and state-of-art in motion-driven miniature energy harvesters and discusses trends, suitable applications, and possible future developments.

/pdf/energy-harvesting-from-human-and-machine-motion-for-wireless-3lsf4oudvo.pdf

Energy Harvesting From Human and Machine Motion for Wireless Electronic Devices

The proper operation of self-organizing networks (SONs) relies on the autonomous behavior of their individual nodes. Routing in such networks has been a challenging task since their conception, due to their nontraditional characteristics and design requirements. Although a large amount of routing architectures and protocols for SONs has been proposed, very little work has been done on the fundamental characteristics that make a routing strategy efficient for a particular network and/or design requirement. Contrary to traditional techniques where the routing architecture is structured as a single unit, we suggest in this article that routing be thought of as a combination of four main architectural components, namely, addressing, dissemination, discovery, and forwarding. This logical decomposition offers significant advantages from both the analysis and the design perspectives. We conclude from our observations that routing architectures should be scenario-driven, in the sense that the configuration parameters are not necessarily universally good for all application scenarios

Dissecting the routing architecture of self-organizing networks

Simulation and emulation techniques are commonly used to evaluate the performance of complex networked systems. Simulation conveniently predicts the behavior of a complex networked system while usually requiring fewer simplifying model assumptions often necessary for theoretical analysis. In contrast, emulation does not need to re-implement the target real systems, so it may improve on the implementation efficiency of simulation while maintaining much of the realism of testbeds. A hybrid approach in which simulation nodes connect to emulation hosts can be used to combine the advantages of both approaches. In this paper, we propose integrating simulation with emulation using adaptive time dilation to evaluate system performance. If a simulator schedules its events in real time and the simulation time keeps up with the real time, then the hybrid system works very well and meets its deadlines. However, a heavily-loaded simulator can introduce significant simulation delays and thereby create situations where these delays impact the accuracy of the system. Our approach uses time dilation to reduce simulation delays and thus increasing the accuracy of the integrated simulation and emulation system. Our adaptive time dilation dynamically controls the time dilation factor to avoid system overloads for both the simulation and the emulation components and to improve the execution correctness of the hybrid system.

Integrated simulation and emulation using adaptive time dilation

Large wireless sensor networks promise to revolutionize the way we sense and control the physical world. In large networks the nodes within the range of the base station forward data on behalf of the entire network. Under reasonable assumptions, as this burden significantly shortens the lifespan of these nodes, the network may become disconnected (and, hence, unusable) while considerable battery resources remain unused at the peripheral nodes. To alleviate this undesired effect, we investigate the effect of multiple battery levels to maximize the useful lifetime of the network. We demonstrate a powerful, yet attractively simple scheme to redistribute the total energy budget in multiple (but few) battery levels. We show by theoretical analysis, as well as simulation, that this substantially improves the network lifetime.

http://dutta.csc.ncsu.edu/research_pubs/doughnut_journal.pdf

On the Lifetime of Large Wireless Sensor Networks with Multiple Battery Levels

http://dutta.csc.ncsu.edu/research_pubs/sharat_comcom.pdf

Adaptive ad hoc self-organizing scheduling for quasi-periodic sensor network lifetime

Localization of a radio frequency (RF) transmitter with intermittent transmissions is considered via a group of unmanned aerial vehicles (UAVs) equipped with omnidirectional received signal strength (RSS) sensors. This group embarks on an autonomous patrol to localize and track the target with a specified accuracy, as quickly as possible. The challenge can be decomposed into two stages: 1) estimation of the target position given previous measurements (localization), and 2) planning the future trajectory of the tracking UAVs to get lower expected localization error given current estimation (path planning). For each stage we compare two algorithms in terms of performance and computational load. For the localization stage, we compare a detection based extended Kalman filter (EKF) and a recursive Bayesian estimator. For the path planning stage, we compare steepest descent posterior Cramer-Rao lower bound (CRLB) path planning and a bio-inspired heuristic path planning. Our results show that the steepest descent path planning outperforms the bio-inspired path planning by an order of magnitude, and recursive Bayesian estimator narrowly outperforms detection based EKF.

Mihail L. Sichitiu

Papers

Dissecting the routing architecture of self-organizing networks

Integrated simulation and emulation using adaptive time dilation

On the Lifetime of Large Wireless Sensor Networks with Multiple Battery Levels

Adaptive ad hoc self-organizing scheduling for quasi-periodic sensor network lifetime

Autonomous Tracking of Intermittent RF Source Using a UAV Swarm