Taha Landolsi

Optical performance monitoring

Progress in optical networking has stimulated interest in optical performance monitoring (OPM), particularly regarding signal quality measures such as optical signal-to-noise ratio (SNR), Q-factor, and dispersion. These advanced monitoring methods have the potential to extend fault management and quality-of-service (QoS) monitoring into the optical domain. This paper reviews OPM applications and techniques, while examining the role of OPM as an enabling technology for advances in high-speed and optically switched networks.

Smart Home Area Networks Protocols within the Smart Grid Context

The Internet of things (IoT) applications are becoming one of the emerging smart grid enabling technologies. Smart home appliances are one the beneficiary of such applications. Machine-to-Machine and Man-to-Machine are the basic IoT communication platforms that enable home appliances to communicate with each other to be more efficiently operated. In a recent search for the IoT communication protocols that are utilized in smart home appliances, there was no inclusive reference that contains and describes the smart home area networks and guides the research and development (R&D) professionals to select the suitable protocol for an application. This paper presents a comprehensive review of the home area network (HAN) communication protocols that are used to enable bidirectional communication between the home owners, utilities and smart home appliances. The paper presents the most utilized HANs wired and wireless communication protocols and discusses their characteristics, advantages and disadvantages.

Wireless Stand-alone Portable Patient Monitoring and Logging System

In this paper, we propose a wireless stand-alone, embedded system design that integrates the monitoring of three biomedical parameters into a single personal medical device. The three parameters are: blood glucose level, heart rate, and pulse oximetry. The goal of this work is to build a compact and cost-effective device capable of monitoring several medical parameters while patients conduct their normal daily activities, and store these parameter readings in an embedded system-based portable device. A communication protocol and patient monitoring software application are developed to store data that can be later downloaded to a physician’s workstation for analysis and diagnosis.

Energy consumption considerations in dynamic wireless sensor networks with nodes and base stations mobility

Energy conservation is a critical issue in the design of sensor networks since the sensor nodes are battery-powered. This paper proposes a wireless sensor network with mobile sensor nodes and base stations to prolong the network lifetime. The movement of base stations inside the covered region is done according to the evolution of current events. The proposed scheme is based on minimising the average consumed energy for every active sensor when data is transmitted. Performance evaluation of the proposed wireless dynamic sensor network is done with a comparison of the network lifetime with the case of static sensor nodes and the base stations.

Accuracy of the split-step wavelet method using various wavelet families in simulating optical pulse propagation

In this paper, we use the split-step wavelet method with various wavelet families to simulate the propagation of optical pulses in single-mode fibers. We compare the accuracy of the simulation results yielded by various orders of Daubechies, Coifman, Meyer and Symlet wavelet families.

A fair scheduling algorithm for video transmission over wireless packet networks

In this paper we propose a fair-scheduling algorithm for the transmission of video frames over wireless links. The scheme is based on the occupancy of the video decoder buffer. When the occupancy of the decoder buffer of a given video client becomes increasingly small and approaches a starvation threshold, it gets treated with a higher priority and gets serviced more frequently than other clients who may not be approaching the starvation point. When compared to other commonly-used scheduling algorithms, ours shows a better performance in terms of the end-to-end delay experienced by the video frames.

A Preliminary Study toward Wireless Integration of Patient Information System

This paper presents the results of a study toward generating a wireless environment to provide real-time mobile accessibility to patient information system. A trial system is set up where database, Internet, and wireless personal digital assistants (PDAs) are integrated in such a way that the medical professionals like physicians, nurses, and lab assistants can create, access, and update medical records using wireless PDAs from any location in the hospital, which is covered by wireless LAN. The same services, which can be carried out via fixed terminals with Internet connectivity, can be carried out using wireless PDAs. The implementation has used and integrated many technologies like Active Server Pages (ASP), Visual Basic®, Structured Query Language (SQL) Server, ActiveSync®, IEEE802.11 Wireless Local Area Network (WLAN) technology and wireless security concepts. The paper details the architectural aspects of technology integration and the methodology used for setting up the end-to-end system. The proposed architecture, its performance data, and the common implementation barriers are reported.

Performance Evaluation of Optically Preamplified PPM Systems With Dual-Polarized ASE Noise and Finite Extinction Ratios

Pulse position modulation (PPM) presents several advantages in free-space optical systems, unrepeatered fiber transmission, and passive optical networks. In this paper, we study the error performance in direct-detection optically preamplified M-ary PPM optical communication systems. We consider the impact of the amplifier spontaneous emission noise, as well of the finite extinction ratio of the transmitter, on the probability of bit error at the receiver. We derive expressions for the probability of bit error under both assumptions of noise polarization, namely, single- and dual-polarized amplifier noise, and compute it numerically for different symbol sizes M and extinction ratios. In addition, we present the power penalty due to the transmitter finite extinction ratio for systems with and without forward error correction. Our findings show that, in the cases of practically achievable finite extinction ratios, systems with smaller M may perform equally well when compared to those using higher values of M. We also show that there is little benefit, if any, associated with using a polarization filter in the receiver since the additional size, weight, and power consumption requirements outweigh the error performance improvement.

Position detection and vibration monitoring system using quad-cell optical beam power distribution

Abstract In this paper, we study the accuracy of an optical vibration sensing system using Gaussian beam analysis. The proposed optical system uses a He–Ne laser source whose Gaussian beam impinges on a quad-cell photodetector array. The normalized optical power for each cell is obtained through numerical simulation based on the well-known Gaussian beam optics formulation, as the beam scans the plane of the photodetectors due to vibration. The system detection principle lies upon finding a relationship between the power distribution of the quad-cell and the position of the beam centroid, which allows us to identify the characteristics of the vibration applied, such as direction, frequency and strength. The aspects of practical implementation and experimental limitations on the power distribution accuracy are discussed and the discrepancies with the theoretical results are presented.

Modeling and Analysis of a Wavelet Network-Based Optical Sensor for Vibration Monitoring

In this paper, we present a wavelet network (WN)-based optical position sensor for vibration monitoring using a quad-cell photodetector array. The proposed system uses a He-Ne laser source whose Gaussian beam impinges on the photodetector array. The optical power distribution from the photodetectors is acquired and fed to a position detection system, which maps the power distribution to the x-y position of the laser beam center. The position detection system uses a WN for function approximation to yield the correct mapping. The advantage of the WN is its generalization property. The network can be trained using a small size lookup table and, when properly trained, can provide a correct estimate of the laser position even if the power readings were not included in the training set. An accurate theoretical model of the system was derived to simulate the optical power variation as the beam scans the photodetector array. An experimental setup was next developed to validate the theoretical model. The results obtained show the effectiveness of WNs to estimate the laser beam position for the purpose of vibration monitoring.