Wireless Sensor Networks(WSNs) have gained a lot of attention because of their potential to immerse deeper into people' lives. The applications of WSNs range from small home environment networks to large habitat monitoring. These highly diverse scenarios impose different requirements on WSNs and lead to distinct design and implementation decisions. This thesis presents an optimization framework for WSN design which selects a proper set of protocols and number of nodes before a practical network deployment. A Genetic Algorithm(GA)-based Sensor Network Design Tool(SNDT) is proposed in this work for wireless sensor network design in terms of performance, considering application-specific requirements, deployment constrains and energy characteristics. SNDT relies on offine simulation analysis to help resolve design decisions. A GA is used as the optimization tool of the proposed system and an appropriate fitness function is derived to incorporate many aspects of network performance. The configuration attributes optimized by SNDT comprise the communication protocol selection and the number of nodes deployed in a fixed area. Three specific cases : a periodic-measuring application, an event detection type of application and a tracking-based application are considered to demonstrate and assess how the proposed framework performs. Considering the initial requirements of each case, the solutions provided by SNDT were proven to be favourable in terms of energy consumption, end-to-end delay and loss. The user-defined application requirements were successfully achieved.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Naiqian Zhang / A two-tier wireless data communication system was developed to remotely monitor sediment concentration in streams in real time. The system used wireless motes and other devices to form a wireless sensor network to acquire data from multiple sensors. The system also used a Stargate, a single-board computer, as a gateway to manage and control data flow and wireless data transfer. The sensor signals were transmitted from an AirCard on the Stargate to an Internet server through the General Packet Radio Service (GPRS) provided by a commercial GSM cellular carrier. Various types of antennas were used to boost the signal level in a radio-hostile environment. Both short- and long-distance wireless data communications were achieved. Power supplies for the motes, Stargate, and AirCard were improved for reliable and robust field applications. The application software was developed using Java, C, nesC, LabView, and SQL to ensure seamless data transfer and enable both on-site and remote monitoring. Remote field tests were carried out at different locations with different GPRS signal strengths and a variety of landscapes. A three-tier wireless sensor network was then developed and deployed at three military installations around the country – Fort Riley in Kansas, Fort Benning in Georgia, and Aberdeen Proving Ground in Maryland - to remotely monitor sediment concentration and movement in real time. Sensor nodes, gateway stations, repeater stations, and central stations were strategically deployed to insure reliable signal transmissions. Radio signal strength was tested to analyze effects of distance, vegetation, and topographical barriers. Omni- and Yagi-directional antennas with different gains were tested to achieve robust, long-range communication in a wireless-hostile environment. Sampling times of sensor nodes within a local sensor network were synchronized at the gateway station. Error detection algorithms were developed to detect errors caused by interference and other impairments of the transmission path. GSM and CDMA cellular modems were used at different locations based on cellular coverage. Data were analyzed to verify the effectiveness and reliability of the three-tier WSN.

A wireless sensor network is a network consisting of spatially distributed, sometimeautonomous sensors, communicating wirelessly to cooperatively achieve some task. For example, a wireless sensor network may be used for habitat monitoring to ascertain the environment’s temperature, pressure, humidity, etc. In order for a wireless sensor network to provide such data, one needs to ensure there is connectivity between nodes. That is, nodes can communicate to exchange information. To analyze connectivity between sensors, the radio communication range of each sensor, also called the communication footprint, needs to be known. To date, the models used to analyze a sensor’s radio communication footprint have been overly simplistic (i.e., isotropic) and thus yield results not found in practice. Footprints are highly dependent on the deployment environments, which are typically heterogeneous and non-isotropic in structure. In this work, a ‘weak-monotonicity’ (W-M) model is leveraged to represent a footprint’s non-isotropic behavior. The work also considers the heterogeneity of the environment through the use of the log-normal shadowing model. In particular, the usable percentage of the W-M footprint (the area where the power exceeds the receiver threshold) in such environments is considered through analysis and simulation. We then develop an enhanced footprint model which overlays multiple W-M patterns and use this method to represent experimental propagation data. The work also considers the use of graph theory methods to analyze the connectivity of randomly deployed networks in nonhomogeneous, non-isotropic environments.

Recent advances in wireless sensor networks have led to an emergence of many routing protocols. Limited battery capacity of sensor nodes makes energy efficiency a major and challenge problem in wireless sensor networks. Thus, the routing protocols for wireless sensor networks must be energy efficient in order to maximise the network lifetime. In this thesis, we developed a centralised clustering, energy-efficient routing protocol for wireless sensor networks. Our protocol consists of a cluster head selection algorithm, a cluster formation scheme and a routing algorithm for the data transmission between cluster heads and the base station. The cluster head selection algorithm is performed by the base station using global information of the network. This algorithm aiming at choosing cluster heads that ensure both the intra-cluster data transmission and inter-cluster data transmission are energy-efficient. The cluster formation scheme is accomplished by exchanging messages between non-cluster-head nodes and the cluster head to ensure a balanced energy load among cluster heads. The routing algorithm is based on the optimal transmission range for the data transmission between cluster heads and the base station using multi-hop. The performance of our routing protocol is evaluated by comparing with three existing routing protocols on a simulation platform. The simulation results show that our protocol can achieve better performance in terms of energy efficiency and network lifetime. Because of the centralised algorithm and multi-hop routing, there is a small communication overhead and transmission delay when using our protocol. Since our protocol can save energy and prolong network lifetime, it is well suited for applications where energy and network lifetime are the primary considerations and small overhead and time delay can be tolerated. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1456494 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Electrical and Electronic Engineering, 2009

<p>To predict the lifetime of wireless sensor networks before their installation is an important concern. The IEEE 802.15.4 standard is specifically meant to support long battery life time; still there are some precautions to be taken by which a sensor network system application based on the standard can be made to run for longer time periods.</p><p>This thesis defines a holistic approach to the problem of energy consumption in sensor</p><p>networks and suggests a choice of node architecture, network structure and routing</p><p>algorithm to support energy saving in the network. The idea and thrust of the thesis is that stand-alone measures such as selecting a low-power microcontroller with embedded transceiver will not alone be sufficient to achieve energy saving over the entire network. A comprehensive design study with energy saving as a primary task must be made. Focus given on the design objectives needs to look at different aspects – application code, network configuration code, routing algorithms etc to come up with an energy efficient network.</p>

<p>Wireless Sensor Network (WSN), a collection of “sensor nodes” promises to change the scientist’s approach of gathering the environmental data in various fields. Sensor nodes can be used for non-stop sensing, event detection, location sensing and local control of actuators, this concept gives surety to many latest application areas like agriculture, military, home or factory automation, logistics and so on. Remote surveillance and measurement missions can be performed by using WSNs. The hot research topic now-a-days is to make such networks remotely controllable and adaptive to the environment and mission.</p><p> </p><p>The work carried out in this thesis is the development of a surveillance application using TinyOS/nesC. The purpose of this application is to perform event-detection mission by using any one of the built-in sensor on Mica2 motes as well as a setup protocol is designed to make the WSN remotely controllable and adaptive to the mission. In this thesis, an experimental work is also performed using TinyDB to build up a surveillance system whose purpose is to detect and count the total number of person present at any time in a given room and to view the results at a remote place. Besides these two system applications, a comparative study between TinyDB and nesC is described which concludes that more hardware control can be achieved through nesC which is a more power efficient platform for long-term applications.</p>

<p>There has been a quick development in the wireless network area during the last decade. Mostly </p><p>these days the focus in the wireless area is on very high speed and long range applications. This </p><p>thesis describes how ZigBee is suitable for wireless sensor networks in logistic telemetry </p><p>applications for global managing and monitoring of goods. ZigBee has been developed by the </p><p>organization named as ‘ZigBee Alliance’ as a new wireless standard for the wireless solutions </p><p>based upon the IEEE 802.15.4 Standard [2]. ZigBee is a new technology as compared to the other </p><p>wireless technologies such as Bluetooth, but it has certain characteristics such as low cost, low </p><p>power, support for mesh networking e.t.c which makes its chances to be more successful than </p><p>others. </p><p> </p><p>The other aim of this thesis is to examine different issues related to ZigBee to see its fitness for </p><p>logistic telemetry applications like multi-hop routing issues, routing strategies and design </p><p>requirements. ZigBee is relatively new wireless technology, so there are great deals of promises </p><p>associated with it. In this thesis, a comparison between ZigBee and Bluetooth technologies will </p><p>also be made.</p>

Wireless Sensor Network (WSN), a collection of “sensor nodes” promises to change the scientist’s approach of gathering the environmental data in various fields. Sensor nodes can be used for non-stop sensing, event detection, location sensing and local control of actuators, this concept gives surety to many latest application areas like agriculture, military, home or factory automation, logistics and so on. Remote surveillance and measurement missions can be performed by using WSNs. The hot research topic now-a-days is to make such networks remotely controllable and adaptive to the environment and mission. The work carried out in this thesis is the development of a surveillance application using TinyOS/nesC. The purpose of this application is to perform event-detection mission by using any one of the built-in sensor on Mica2 motes as well as a setup protocol is designed to make the WSN remotely controllable and adaptive to the mission. In this thesis, an experimental work is also performed using TinyDB to build up a surveillance system whose purpose is to detect and count the total number of person present at any time in a given room and to view the results at a remote place. Besides these two system applications, a comparative study between TinyDB and nesC is described which concludes that more hardware control can be achieved through nesC which is a more power efficient platform for long-term applications.

There has been a quick development in the wireless network area during the last decade. Mostly these days the focus in the wireless area is on very high speed and long range applications. This thesis describes how ZigBee is suitable for wireless sensor networks in logistic telemetry applications for global managing and monitoring of goods. ZigBee has been developed by the organization named as ‘ZigBee Alliance’ as a new wireless standard for the wireless solutions based upon the IEEE 802.15.4 Standard [2]. ZigBee is a new technology as compared to the other wireless technologies such as Bluetooth, but it has certain characteristics such as low cost, low power, support for mesh networking e.t.c which makes its chances to be more successful than others. The other aim of this thesis is to examine different issues related to ZigBee to see its fitness for logistic telemetry applications like multi-hop routing issues, routing strategies and design requirements. ZigBee is relatively new wireless technology, so there are great deals of promises associated with it. In this thesis, a comparison between ZigBee and Bluetooth technologies will also be made.

The use of a wireless sensor network (WSN) to monitor an historic structure under rehabilitation is the focus of this research. To thoroughly investigate the issue, two main objectives are addressed: the development of a reliable WSN tailored for use in historic structures, and the implementation of the monitoring system in the field to test the feasibility of the WSN and its applicability for structural health monitoring (SHM). Three field studies are undertaken in this research. The Frankford Church, an historic wooden church which required foundation replacement, is the first field study. Sensors monitor tilt of the church’s walls throughout construction. During the construction process, the entire floor of the church is removed and the tree stump foundations are replaced by concrete masonry unit (CMU) blocks and steel pedestals. The tilt in the walls is correlated to the construction process. St. Paul Lutheran, an historic masonry church with timber-framed roof, constitutes the second field study. In this structure, the foundations along the exterior walls are underpinned and the floors are removed and replaced with a floating concrete slab. Detected movements are also correlated to the construction efforts. The Johanniskirche, an historic masonry church with moisture problems, is the final field study case. Real-time and past measured WSN climate data is used to determine the most appropriate solution for the humid climate and resulting condensation problems in this structure. From these results, a moisture migration risk analysis protocol is created for use with a WSN to address condensation issues. The results of the tilt monitoring indicate that the approach is realistic to monitor tilt in the walls of historic structures. For future research, it is recommended to implement motes with higher tilt sensitivity. Also, further development of energy saving algorithms and energy harvesting methods will improve the WSN’s performance. Climate monitoring results show it is feasible to monitor climate conditions of historic structures. The moisture migration protocol provides a basis for further improvement. Implementation of this tool will help predict condensation events and prevent future damage to the historic structure.