Investigation of techniques for combating malicious objects in unreliable wireless sensor networks

Unreliable net\vorks can take many different forms such as in the general case an ad hoc network or more specifical1y as a wireless sensor networks (WSNs). Some of the fields you can [md these types of networks used in would be the telecommunications industry with mobile phones, biological research for monitoring animals in the wild and military applications to monitor soldiers. Networks in these areas are handling an increasing amount of data. This data is very valuable and therefore a source of concern in making sure that none of it is lost or damaged. From a security standpoint there are many ways that an attack on these types of networks can be implemented. Some attacks are rather difficult to execute and would require knowledge of the particular network that is being attacked to be effective. One of the most effective attack methods would be for the attacker to inject its own data into the network either with the simplest goal of consuming network resources or having some other purpose such as capturing or corrupting the data stored in the network. Thinking in terms of biological systems the data that these attackers inject into the network is similar to a virus entering a human body. In the medical field medicine can be used to help cure a person by targeting this virus, in much the same way this chapter considers introducing a special type of anti-virus to the network to remove this data inserted by an attacker. This chapter considers leveraging the properties of unreliable network combined with a recommended approach employing an anti-virus to remove the virus from the network effectivel

Prospects and problems of cognitive radio network architectures in wireless sensor networks

Cognitive radio is a technique proposed by Mitola which provides a way to efficiently use precious radio spectrum resources [1, 2]. A cognitive radio recognizes, analyzes, and learns the situations of the radio spectrum and then employs various strategies to maximize spectrum usage. The concept of cognitive radio is to detect and ascertain \vhich aspect of the spectrum is presently unused, and then perform data transmission at the newly discovered frequency band. An alternative cognitive radio scheme is to transmit signals on top of existing transmissions as long as the interference temperature measure is lower than threshold. Spectrum sharing, spectrum sensing, and spectrum management are the stages of a cognitive radio. Spectrum sensing gathers up-to-date spectrum usage data, spectrum management determines the optimal spectrum access timing and scheme, and spectrum sharing ensures that users are served in a fair and timely mann

Piece-wise linear analog to digital (PLADC) converter process

Transducers are devices that transform energy from one form to another. Such transformation process may be applicable in the measurement of physical quantities, transfer of information and also in performing a certain control action. Transducers used as measuring devices are generally termed as sensors. Such transducers detect the changes in characteristics of a physical quantity and convert the change into a corresponding electrical signal. This is a common phenomenon when transducers are used to detect temperature, speed, force, liquid level or viscosity. On the other hand transducers, used to carry out control actions, are termed as actuators. These transducers usually convert an electrical signal into some form of physical control action such as heating or movement and are carried by the control devices. Various types of transducers exist meant for sensing and controlling different physical quantities. For example, a light dependent resistor (LOR) or a photodiode can be used to sense light intensity of an environment while lamps and LED displays can be used to control it. Likewise, a thermistor can be used to measure the temperature of an environment while a heater/fan can be used to control it and a tachometer can be used to measure the speed of a device while a stepper motor can be used to control it [1-3]. The focus of this chapter is on the problems and issues related to the interfacing of transducers when used as measuring devices or sensors in smart applications. Smart applications are also termed as tuned control for detecting changes in the parameter of interest which used to be ignorable in the traditional measurement and control system

Practical applications and design challenges of wireless heterogeneous sensor networks

Heterogeneous, {hetero + genos 'type', from Greek), is defined in Oxford Advanced Learner's Dictionary as "consisting of many different kinds of people or things" and defined in Longman Dictionary as "consisting of parts or members that are very different from each other." The design of interconnected nodes may be heterogeneous or homogeneous with the aim of catering for the design demands and purpose of various wireless applications. The heterogeneity or homogeneity of the interconnected nodes designed is with respect to their ability to sense events, transmit desired sensed data, computing and processing user queries, managing of energy resources and minimizing the complexity of the hardware design. The participating nodes in heterogeneous networks may be different in many aspects. They could have ditferent transmission radius, various kind of sensing units, different hardware power, and dit1erent power supply. Nodes with lesser energy resources serve as sensing nodes to collect physical information while nodes with more energy resources serve as data sinks. Heterogeneity could be viewed either in terms of capability or functionality of sensor nodes. In homogeneous networks, all the participating and active nodes are alike in nature and the same transmit power level is used for their operation. These alike nodes are inherently built with the same sensing units to track a single event [5, 9, 10]. Cluster heads and cluster members have different tasks in clustered sensor networks in the course of data delivering to the base station. An example is a tiered sensor network architecture where 802.11 mesh network comprise of high-end nodes, such as Intel XScale nodes which are deployed on a plain WSN fiel

Information and communication privacy in wireless sensor networks

This chapter places special emphasis on sensor networks applications in a battlefield.When a sensor network is used to monitor soldiers' movements in a battlefield, information about the soIdiers' whereabouts is sent back to the base station and accessed by commanders in the headquarters as shown in Figure 33.1. Before the fight, planes fly over the battlefield and deploy the sensors. These sensors organize themselves into a network and transmit data collected from the battlefield and send them back to the base statio

Design and implementation of an optimal fuzzy logic controller using genetic algorithm

All control systems suffer from problems related to undesirable overshoot, longer settling times and vibrations while going form one state to another state. Most of relevant techniques had been in the form of suggesting modification and improvement in the instrumentation or interfacing part of the control system and the results reported, remain suffering from shortcomings related to hardware parameter dependence and maintenance and operational complexities. Present study was based on a software approach which was focusing on an algorithmic approach for programming a PIC16F877A microcontroller, for eliminating altogether the parametric dependence issues while adding the benefits of easier modification to suit a given control system to changing operational conditions. Said approach was first simulated using MATLAB/SIMULINK using the techniques of Proportional Derivative Fuzzy Logic Controller (PD-FLC) whose membership function, fuzzy logic rules and scaling gains were optimized by the genetic algorithm technique. Simulated results were verified by programming the PIC16F877A microcontroller with the algorithm and using it on a temperature control system where a fan was regulated in response to variations in the ambient system temperature. Resulting tabulated performance indices showed a considerable improvement in rising and settling time besides reducing overshoot and steady state error