Nejah Nasri

A New Approach for Clustering in Wireless Sensors Networks Based on LEACH

Abstract Wireless sensors networks (WSNs) are traditionally composed of large number of low-cost and tiny homogenous sensors nodes connected through a wireless network that gather data to be treated locally or relayed to the sink node through multi-hop wireless transmission. Moreover, such issues are very critical due servers resources constraints like efficient energy, stock limitation and lifetime of network. Several solutions were proposed to minimize the traffic into network. Clustering algorithms have been widely used to reduce energy consumption. In this context, the key point in such topology is to select a cluster. One of solutions is to select a cluster alternately. However, this choice does not consider the energy as important criteria in actual papers. In order to limit energy consumption, our new method is proposed in this paper to optimization Low Energy Adaptive Clustering Hierarchy (O- LEACH) to improve existing LEACH and LEACH-C by selecting cluster according to the residual energy of nodes dynamically. The simulation results show that proposed algorithm achieve longer stability by comparison to original LEACH and LEACH-C.

BLE localization using RSSI measurements and iRingLA

Over the last few years, indoor localization has been a very dynamic research area that has drawn great attention. Many methods have been proposed for indoor positioning as well as navigation services. A big number of them were based on Radio frequency (RF) technology and Radio Signal Strength Indicator (RSSI) for their simplicity of use. The main issues of the studies conducted in this field are related to the improvement of localization factors like accuracy, computational complexity, easiness of deployment and cost. In our study, we used Bluetooth Low Energy (BLE) technology for indoor localization in the context of a smart home where an elderly person can be located using an hybrid system that combines radio, light and sound information. In this paper, we propose a model that averages the received signal strength indication (RSSI) at any distance domain which offered accuracy down to 0.4 meters, depending on the deployment configuration.

Design considerations for wireless underwater communication transceiver

Evolutionary processes have shaped acoustic communication behaviours of remarkable complexity, for thus many researches have led to the development of innovative receiver structures for robust underwater acoustic communication. As underwater channel model, attenuation, transmission distance, low power consumption, highly Signal to Noise Ratio, Bit Error Ratio, inter-symbol interference, error coding and alternative modulation strategies, are of primary concern in the whole study and in particularly the proposition of the transceiver structure and his design. The values of these parameters above - mentioned are crucial to improve the wireless underwater communication. In addition, the battery powered Network nodes limit the life time of the proposed transceiver. This paper aims to survey the existing and the reliability of this transceiver and its applicability to underwater communication based on these simulations parameters values that are evaluated and presented.

An Energy-Efficient Unequal Clustering Algorithm Using `Sierpinski Triangle' for WSNs

Maximizing the nodes lifetime is one of the major issues in the wireless sensor networks (WSNs). Clustering algorithms represent the most well-known solution for optimizing the total consumed energy of WSNs. In clustered WSNs, each sensor is able to supervise an event and send information to its cluster head (CH) which aggregates and transmits data to the base station (BS) through other CHs in the network. This scenario causes the ‘hot spots’ problem where closer CHs to the BS tend to die earlier because of the heavy relay data. Unequal clustering algorithms have tried to solve this problem and control the size of each cluster in the network. In this paper, we proposed a new unequal clustering algorithm called energy degree distance unequal clustering algorithm (EDDUCA) aiming to balance energy consumption and maximize the network lifetime. EDDUCA uses the ‘Sierpinski triangle’ method in order to devide network into unequal clusters. The obtained results indicate that EDDUCA can effectively balance the energy consumption and therefore can lengthen the network lifetime.

Routing protocols in MANET: Performance comparison of AODV, DSR and DSDV protocols using NS2

A mobile Ad-hoc Network (MANET) become the one of top area of research, due to their simplicity of deployment. No infrastructure is required for nodes to connect with each other in the network, and with out aid of centralized administration. The nodes with MANET are quickly deployable, independent and self repair. Despite these advantages routing protocols suffering from many problems like mobility, synchronization, localization, long route and other while routing. Therefore this protocols should be study in depth, simulated in different conditions and classified. this classification and simulation helps in understanding, comparing performances and assist researchers to differentiate the characteristics and define the pros and cons of routing protocols. A detailed study and simulation model using Network Simulator (NS-2.34) with different traffic models are presented in this paper. The simulation and the performance study will focus on the impact of the network size, average energy consumption per received packet and the network density.

Efficient encoding and decoding schemes for wireless underwater communication systems

This work focuses on presenting a novel high efficiency channel encoding for transmitting acoustical signals in the hope of improving wireless underwater communication. Yet, water puts a damper on communication capacity, slowing down the signal propagation and creating background noise and echoes. For thus systems and methods for implementing a control channel, e.g., in underwater communication system, are presented below. Aspects of the channel structures used to implement the control channel described herein, can improve error detection capabilities, reduce decoding complexity, and increase transmission efficiency. In certain aspects, transmission efficiency can be increased through using CRC encoding. A circular trellis check and Viterbi decoding can also be used to increase efficiency and maintain error detection capabilities. Symbol Error Rate (SER) can be reduced in embodiments described herein over that of tail-biting convolutional coding with a CRC. Furthermore, error detection offered by Reed Solomon encoder can well compensate underwater noise. Additionally, the encoder packet size can be fixed in order to facilitate decoding and reducing receiver complexity.

Optimised cross-layer synchronisation schemes for wireless sensor networks

ABSTRACT This paper aims at synchronisation between the sensor nodes. Indeed, in the context of wireless sensor networks, it is necessary to take into consideration the energy cost induced by the synchronisation, which can represent the majority of the energy consumed. On communication, an already identified hard point consists in imagining a fine synchronisation protocol which must be sufficiently robust to the intermittent energy in the sensors. Hence, this paper worked on aspects of performance and energy saving, in particular on the optimisation of the synchronisation protocol using cross-layer design method such as synchronisation between layers. Our approach consists in balancing the energy consumption between the sensors and choosing the cluster head with the highest residual energy in order to guarantee the reliability, integrity and continuity of communication (i.e. maximising the network lifetime).

Radio Frequency IDentification (RFID) working, design considerations and modelling of antenna

RFID is the acronym of radio frequency identification. It represents a new automated data-capture technology, based on the extraction of data contained in devices called RFID tags or transponders by wireless radio technologies. In the RFID appellation we find RF. For memory, who says RF says laws of the physics such as, laws of Maxwell and those of Biot and Savart that manage the running of the RFID. Otherwise, the reader and the transponder communicate by using electromagnetic waves that assure the transfer of information and the self alimentation of transponders. For thus, the purpose of this paper is to explain the RFID technology and to survey the determination and evaluation of the parameters of a RFID antenna.

Centralized KNN anomaly detector for WSN

This work suggests to detect abnormalities from spatial distribution of data using a numerical outlier data detector in a wireless sensor network (WSN). The detector is able to find anomalous from one or many events by using KNN technique and Euclidian distance. WSN uses a Low Energy Adaptive Clustering Hierarchy protocol (LEACH), where we compute the good impact of detection on energy. From this, a mean time to failure is computed. The evaluation is also with detection rates metrics in order to appreciate the detection accuracy and quality of data.

A novel implantable Planar Inverted-F Antenna for biomedical applications

In recent years, the Wireless Body Area Network WBAN has emerged over the world as a new technology for medical applications. The advent of technology and concern for the patients comfort lead to extreme miniaturization of medical devices. This miniaturization is not done without the degradation of the antennas performance. This paper presents a novel design of rectangular Planar Inverted-F Antenna (PIFA) for biomedical application in Medical Implantable Communications Service band MICS (402-405) MHz. The use of MICS band is of great importance. It is dedicated just for implantable medical applications thus the risk of interference is minimal. Different miniaturization techniques are combined with the use of high dielectric (substrate/superstrate) to fulfill a tradeoff between size and performances. The proposed antenna is characterized by a good performances and a small size 11.9*14.7*1.2 mm3 compared to other implantable antennas in the literature.