Secure Adaptive Topology Control for Wireless Ad-Hoc Sensor Networks

This paper presents a secure decentralized clustering algorithm for wireless ad-hoc sensor networks. The algorithm operates without a centralized controller, operates asynchronously, and does not require that the location of the sensors be known a priori. Based on the cluster-based topology, secure hierarchical communication protocols and dynamic quarantine strategies are introduced to defend against spam attacks, since this type of attacks can exhaust the energy of sensor nodes and will shorten the lifetime of a sensor network drastically. By adjusting the threshold of infected percentage of the cluster coverage, our scheme can dynamically coordinate the proportion of the quarantine region and adaptively achieve the cluster control and the neighborhood control of attacks. Simulation results show that the proposed approach is feasible and cost effective for wireless sensor networks

Topology Control Algorithm considering Antenna Radiation Pattern in Three-Dimensional Wireless Sensor Networks

Topology control is a key issue of wireless sensor network to reduce energy consumption and communication collision. Topology control algorithms in three-dimensional space have been proposed by modifying existing two-dimensional algorithms. These algorithms are based on the theoretical assumption that transmission power is radiated equally to the all directions by using isotropic antenna model. However, isotropic antenna does not exist, which is hypothetical antenna to compare the real antenna performance. In the real network, dipole antenna is applied, and because of the radiation pattern, performance of topology control algorithm is degraded. We proposed local remapping algorithm to solve the problem and applied it to existing topology control algorithms. Simulation results show that our algorithm increases performance of existing algorithms and reduces power consumption

災害時における移動式リソースユニットを用いた通信ネットワークのスループット及び遅延性能改善に関する研究

Tohoku University加藤寧課

Communication system improvement with control performance based on link quality in wireless sensor actuator networks

New communication and networking paradigms started with wireless sensor actuator networks (WSANs) to introduce new applications. One of these is the automatic gain control system (AGC). It will enable a high degree of the decentralized and mobile control. In this study, neural networks (NN) with fuzzy logic (one of the techniques of artificial intelligence (AI)) is used to enhance the control performance depending on the link quality. The NN and fuzzy inference system (FIS) with Mamdani’s method used to build a model reference, adaptive controller, for recompensing for delay time packets losses, and improving the reliability of WSAN. Between 88.62% and 99.99%, validation data is obtained for the medium and high conditions of operation with the proposed algorithm. Experimental and simulation results show a promising approach

Analysis of an Intelligent Temperature Transmitter for Process Control

In recent times, transmitters that incorporate microprocessor to perform various intelligent functions have been developed by various manufacturers. This paper presents an overview of the evolution in transmitter technology while highlighting key factors which have influenced the evolution. It also identifies low power microprocessor and analog to digital converters working with the basic sensor circuit as the key propellants in the advancement of transmitter technology. Despite several sensors available in the process control industry, the authors focus on temperature sensors and analyze a typical Rosemount Intelligent Temperature Transmitter (RITT) with a view to identifying and comparing how experimental results vary from established parameters in the datasheet. Simulation results show that the resistance of the RITT’s Resistance Temperature Detector (RTD) varies directly with applied temperature. Percentage error shows acceptable points at -0.04%, 0.04% and -0.1%. For higher percentage error readings, it is necessary to connect a resistor of value between 250Ω and 1100Ω between the current loop and the transmitter. The future of transmitter technology is however the wireless sensor node (WSN) incorporating the Sensirion SHT11 temperature sensor.http://dx.doi.org/10.4314/njt.v34i3.2

Research of an Adaptive Optimization Topology Control for Heterogeneous Sensor Networks

This paper has focused on the optimization of topology control for heterogeneous energy-saving sensor networks. In the heterogeneous sensor networks, there is initial heterogeneous energy in each sensor node which produces isomerism such as heterogeneous link in the process of wireless communication. Compared with the traditional energy conservation optimum algorithm which doesn't take fully consideration of the communication distance and the allocation of re-clustering after node failure, this paper proposes an network topology control algorithm with adaptive optimizing isomerism for wireless-sensors. In order to expand the life expectancy of network, this algorithm, firstly bases on hop-count of transmission data and the communication distance of adjacent sensors, and then does adaptive optimal control on clustering sensor nodes in specific environment, according to geometric principle of similar triangles. Simulation experiments have shown the improved algorithm can control network topology of all nodes in given data acquisition and monitoring area with high efficiency. Meanwhile, the life cycle of heterogeneous sensor network can be greatly expanded

Application of Particle Swarm Techniques in Sensor Network Configuration

A decentralized version of particle swarm optimization called the distributed particle swarm optimization (DPSO) approach is formulated and applied to the generation of sensor network configurations or topologies so that the deleterious effects of hidden nodes and asymmetric links on the performance of wireless sensor networks are minimized. Three different topology generation schemes, COMPOW, Cone-Based and the DPSO--based schemes are examined using ns-2. Simulations are executed by varying the node density and traffic rates. Results contrasting heterogeneous vs. homogeneous power reveal that an important metric for a sensor network topology may involve consideration of hidden nodes and asymmetric links, and demonstrate the effect of spatial reuse on the potency of topology generators

Optimal Topologies for Wireless Sensor Networks

Since untethered sensor nodes operate on battery, and because they must communicate through a multi-hop network, it is vital to optimally configure the transmit power of the nodes both to conserve power and optimize spatial reuse of a shared channel. Current topology control algorithms try to minimize radio power while ensuring connectivity of the network. We propose that another important metric for a sensor network topology will involve consideration of hidden nodes and asymmetric links. Minimizing the number of hidden nodes and asymmetric links at the expense of increasing the transmit power of a subset of the nodes may in fact increase the longevity of the sensor network. In this paper we explore a distributed evolutionary approach to optimizing this new metric. Inspiration from the Particle Swarm Optimization technique motivates a distributed version of the algorithm. We generate topologies with fewer hidden nodes and asymmetric links than a comparable algorithm and present some results that indicate that our topologies deliver more data and last longer