Ahmed El Oualkadi

Multi-hop Cluster Based Routing Approach for Wireless Sensor Networks.

Abstract One of the key challenges in wireless sensor networks is the efficient usage of restricted energy resources in battery operated sensor nodes. Clustering remains the most effective routing approach used in WSN. Low Adaptive Clustering Hierarchy (LEACH) protocol is an efficient routing approach which has been widely adopted and enhanced to improve the lifespan of deployed sensor networks. However, latterly, clustering algorithms have shown their limitation in extending the network lifespan. In this paper, we propose a new clustering approach based on a combination of LEACH and MTE protocols. The adoption of multi-hop communication instead of direct communication in cluster filed has optimized the communication in the network. The simulation results illustrate the energy efficiency of the multi-hop cluster based routing approach. The proposed method achieves significant improvement in term of network lifespan and provides enhanced energy performance for wireless sensor networks.

On the performance of adaptive coding schemes for energy efficient and reliable clustered wireless sensor networks

Abstract Clustering is the key for energy constrained wireless sensor networks (WSNs). Energy optimization and communication reliability are the most important consideration in designing efficient clustered WSN. In lossy environment, channel coding is mandatory to ensure reliable and efficient communication. This reliability is compromised by additional energy of coding and decoding in cluster heads. In this paper, we investigated the trade-off between reliability and energy efficiency and proposed adaptive FEC/FWD and FEC/ARQ coding frameworks for clustered WSNs. The proposed schemes consider channel condition and inter-node distance to decide the adequate channel coding usage. Simulation results show that both the proposed frameworks are energy efficient compared to ARQ schemes and FEC schemes, and suitable to prolong the clustered network lifespan as well as improve the reliability.

A Hybrid Adaptive Coding and Decoding Scheme for Multi-hop Wireless Sensor Networks

In this paper, we have proposed a hybrid adaptive coding and decoding scheme for multi-hop wireless sensor networks (WSNs). Energy consumption and transmission reliability are used as performance metrics for multi-hop communications in WSNs. The presented scheme takes into account distance, channel conditions and correction codes performance to decide coding and decoding procedure, and considers Reed Solomon code and Low Density Parity Check code to provide error protection on the transmitted data. The proposed approach aims to reduce the decoding power consumption and to prolong the lifetime of the network as well as improve the reliability of the transmission. Simulation results show that our performed scheme enhances both energy efficiency and communication reliability of multi-hop sensor networks.

Performance analysis of efficient coding schemes for wireless sensor networks

Energy consumption in sensor nodes and Link reliability are two of the major challenges in Wireless Sensor Networks (WSNs). The data exchanged between nodes and base station are vulnerable to corruption by errors induced by random noise, signal fading and other factors. In this regard, error control coding (ECC) is an efficient technique used to increase link reliability and to reduce the required transmitted power. In this context, the choice of energy efficient ECC with a suitable modulation scheme is a crucial task at the link and physical layer of wireless sensor networks to improve their lifetime. Since the WSNs are energy constraint in nature, both the probability of bit error rate (BER) and power consumption have to be taken into account. A performance analysis of error control coding schemes referring to BPSK modulation through a Gaussian channel (AWGN) is presented in this paper. Our results show that the RS(31,21) outperforms other ECC schemes and can be the optimal choice for wireless sensor network environment.

5-GHz low phase noise CMOS LC-VCO with PGS inductor suitable for ultra-low power applications

A fully integrated LC-VCO fabricated in 0.13 µm CMOS technology is presented in this paper. The VCO achieves a wide tuning range of 31.43 % (from 3.841 GHz to 5.381 GHz). The measured phase noise is −120.63 dBc/Hz at 1 MHz offset from the carrier at 5.287 GHz. The current dissipation of the VCO is 1.32 mA from the 1.5 V power supply. The VCO figure of merit is greater than 190 placing this design among the top of the state-of-the-art.

Tikhonov-Miller regularization with a denoisy and deconvolved signal as model of solution for improvement of depth resolution in SIMS analysis

In this paper the improvement by deconvolution of the depth resolution in Secondary Ion Masse Spectrometry (SIMS) analysis is studied. Indeed, a new Tikhonov-Miller deconvolution method, where a priori model of solution is included. The latter is a denoisy and pre-deconvolved signal obtained firstly by the application of wavelet shrinkage algorithm and after, by the introduction of the obtained denoisy signal in an iterative deconvolution algorithm. The results of the proposed algorithm are compared to those of Tikhonov-Miller regularization where the model of solution is a raw signal. Finally, based on the obtained results the advantages and limitations of the proposed method as well as suggestions for future work are presented and discussed.

Joint FEC/CRC coding scheme for energy constrained IOT devices

Energy efficiency is of utmost importance in internet of things (IOT) as it tends to rely on battery-powered devices constrained by their limited lifetime, which entails the need of energy-aware protocols. As transmission energy is the most energy consuming, and reliability is of paramount in IOT applications, we advocate the use of error control coding as means to provide reliability and transmission energy saving. Forward error correction (FEC) aims at saving transmission energy and correcting channel errors at the receiver by using channel coding and decoding, yet the complexity of the decoding process affects both the energy and reliability performance of wearable devices. In this work, we propose a joint FEC/CRC scheme to alleviate the decoding energy depletion and provide communication reliability. We thoroughly evaluate the performance of the proposed coding scheme in terms of energy efficiency and reliability in a multi-hop network.

On the design of coding framework for energy efficient and reliable multi-hop sensor networks

Abstract: Energy efficiency and reliability are the key requirements for wireless sensor network (WSN), as sensor nodes are expected to be stand-alone for a long time and communication to be successfully carried out. Communication is the most energy consuming process in WSN, especially in lossy environment. In multi-hop WSN, packets are more susceptible to transmission errors which worsens the communication reliability and energy consumption. Therefore, coding schemes are mandatory to cover the channel impairments and save the transmission energy. In this work, we propose an adaptive coding (AC) scheme that can be adapted with the channel state and inter-node distances in order to decode and correct the packets or request for retransmissions. The proposed scheme has proved to be energy efficient and adaptive compared to Automatic Repeat reQuest (ARQ) and Forward Error Correction (FEC) schemes.

Multi-zonal approach clustering based on stable election protocol in heterogeneous wireless sensor networks

The extension of network life time is the major constraint in wireless sensor network. Routing protocols have a significant impact on the overall energy dissipation and lifespan of these networks. It is important to optimize the energy efficiency performance of communication protocols in order to enhance the system lifetime. Clustering technique is one of the most routing approaches used in WSN for energy efficiency. Several clustered routing protocols have been proposed. However, latterly, clustering algorithms have shown their limitation in extending the network duration. In this paper, we propose a new clustering approach MZ-SEP based on multiple triangle zones distribution and SEP protocol. The partition of sensor deployment field into multiple zones enhances the communication between cluster heads and their members. The obtained simulation results displayed the energy effectiveness of the proposed protocol and show that MZ-SEP approach outperforms SEP protocol by significantly improving the network lifetime and the stability period.

Simulation and Experimentation of an RFID System in the UHF Band for the Reliability of Passive Tags

This paper presents the simulation of a UHF RFID (Radio Frequency Identification) system for passive tags, using Advanced Design System software from Agilent Company. Temporal measurements based on a commercial RFID reader are achieved which permit to analyze and to validate the principles of communication between the reader and the tag. Also a test bench is developed to evaluate the effects of high temperature on the reliability of passive UHF RFID tags. The obtained test results show that the thermal storage has a marked effect on the performances of the RFID tags.