A large-scale distributed wireless sensor network is composed of a large collection of small low-power, unattended sensing devices equipped with limited memory, processors, and short-range wireless communication. The network is capable of controlling and monitoring ambient conditions, such as temperature, movement, sound, light and others, and thus enable smart environments. Energy efficient data dissemination is one of the fundamental services in large-scale wireless sensor networks. Based on the study of the data dissemination problem, we propose two efficient data dissemination schemes for two categories of applications in large-scale wireless sensor networks. In addition, our schemes provide spatial-based multi-resolution data dissemination for some applications to achieve further energy efficiency. Analysis and simulation results are given to show the performance of our schemes in comparison with current techniques.

<p>Wireless sensor networks are emerging from the mobile ad hoc network concept and as such they share many similarities. However, it is not the similarities that differentiates sensor networks from their ad hoc counterparts, it is the differences. One of the most important difference is that they should operate unattended for long periods of time. This is especially important since they usually rely on a finite energy source to function. To get this into a perspective, a sensor network constitutes of a sensor field where a number of sensor nodes are deployed. The sensor nodes relay the gathered information to a base station from which the data are forwarded either through a network or directly to the enduser. The communication between sensor nodes are conducted in an ad hoc manner, which means that paths toward the base station are dynamically constructed based on current network conditions. The network conditions changes and examples of this includes node failure, deactivated nodes, variations in the radio channel characteristics, etc.</p><p>As mentioned above, the sensor nodes are energy constrained and one of the more important design criteria is the life time of a sensor node or network. To be able to evaluate this criteria an energy dissipation model is needed. Most of the energy dissipation models developed for wireless sensor networks are not based on the basic sensor node architecture and as such they where not accurate enough for our needs. Thus, an energy dissipation model was developed. This model utilises the basic sensor node architecture to obtain the operation states available and their corresponding state transitions.</p><p>Communication is the most energy consuming task a sensor node can undertake. As such, the contributed energy dissipation model is used to evaluate this aspect of the proposed controlled flooding protocols. Generally, the controlled flooding protocols tries to minimise the number of forwarding nodes and by doing this they lower the energy consumed in the network. Along with this, the communication overhead of a protocol also needs to be taken into account. Our idea is to utilise the received signal strength directly to make forwarding decisions based on a cost function. This idea has a number of key features, which are: no additional overhead in the message, no neighbour knowledge and no location information are needed. The results from the proposed flooding protocols are promising as they have a lower number of forwarding nodes and a longer lifetime than the</p><p>others.</p> / Report code: LIU-TEK-LIC-2007:43.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 2006. / Vita. Includes bibliographical references (p.166-171). Online version available

Thesis (M.S.)--Youngstown State University, 2009. / Includes bibliographical references (leaves 67-69). Also available via the World Wide Web in PDF format.

Thesis (M. Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005. / Includes bibliographical references (p. 66-69). Also available online.

This Master’s report presents the research leading to the development of a low power Wireless Sensor Network (WSN) and a discussion of an implementation of the WSN. This report assesses the power reduction techniques further by reviewing their influences upon functionality, throughput, latency, and data reliability. The software techniques were implemented on evaluation boards and actual performance gains were observed. Furthermore, the report provides insight into the selection of the processor, wireless protocol, and WSN architecture by comparing other options in regards to the power reduction, functionality, and data reliability. The architecture of the WSN consists of four sensor nodes, and a backbone router connected to a PC. The sensor nodes contain an application processor and a radio processor. The application processor is a Texas Instruments MSP430F5438 which is located on an MSP-EXP430F5438 evaluation board. The radio processor is a NIVIS Versa Node 210 that is located on a VS210 development board. The wireless protocol investigated is the ISA100.11a. / text

Wireless sensor nodes are resource constrained and have limited amount of energy. Therefore, designing protocols that conserve energy is an important area of research. Researchers have investigated architectures and topologies that allow energy efficient operation of WSNs. One of the popular techniques in this regard is clustering. A typical clustering protocol contains two main steps: cluster head election and cluster formation. This thesis is aimed at investigation of the cluster formation process. We propose a Fuzzy Logic based approach that uses three descriptors namely: energy level, distance between cluster-head and base station, and distance between the cluster-head and the sensor’s node. We compare our proposed model, FLCFP (Fuzzy Logic Clustering Formation Protocol), with the most popular model, LEACH, which was proposed previously to prolong network lifetime. FLCFP approach is shown to prolong network lifetime. In addition, it is shown that sensor node energy is consumed in a more uniform fashion.

Detection of encroachment on pipeline right-of-way is important for pipeline safety. An effective system can provide on-time warning while reducing the probability of false alarms. There are a number of industry and academic developments to tackle this problem. This thesis is the first to study the use of a wireless sensor network for pipeline right-of-way encroachment detection. In the proposed method, each sensor node in the network is responsible for detecting and transmitting vibration signals caused by encroachment activities to a base station (computer center). The base station monitors and analyzes the signals. If an encroachment activity is detected, the base station will send a warning signal. We describe such a platform with hardware configuration and software controls, and the results demonstrate that the platform is able to report our preliminary experiments in detecting digging activities by a tiller in the natural and automotive noise.

In this dissertation, we develop and analyze effective energy management policies for wireless sensor networks in emerging applications. Existing methods in this area have primarily focused on energy conservation through the use of various communication techniques. However, in most applications of wireless sensor networks, savings in energy come at the expense of several performance parameters. Therefore it is necessary to manage energy consumption while being conscious of its effects on performance. In most cases, such energy-performance issues are specific to the nature of the application. Our research has been motivated by new techniques and applications where efficient energy-performance trade-off decisions are required. We primarily study the following trade-off cases: energy and node replacement costs (Case I), energy and delay (Case II), and energy and availability (Case III). We consider these trade-off situations separately in three distinct problem scenarios. In the first problem (Case I), we consider minimizing energy and node replacement costs in underwater wireless sensor networks for seismic monitoring application. In this case, we introduce mixed-integer programming (MIP) formulations based on a combined routing and node replacement policy approach and develop effective policies for large problem instances where our MIP models are intractable. In the second problem (Case II), we develop a Markov decision process (MDP) model to manage energy-delay trade-off in network coding which is a new energy-saving technique for wireless networks. Here we derive properties of the optimal policy and develop in- sights into other simple policies that are later shown to be efficient in particular situations. In the third problem (Case III), we consider an autonomous energy harvesting sensor network where nodes are turned off from time to time to operate in an “energy-neutral” manner. In this case, we use stochastic fluid-flow analysis to evaluate and analyze the availability of the sensor nodes under effective energy management policies. In each of the above problem cases, we develop analytical formulations, and derive and/or analyze policies that effectively manage the considered energy-performance trade-off. Overall, our analyses and solution methods make new contributions to both operations research and communication networking literature.

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