Proposal study to improve the performance of Syrian telecommunication optical networks using Routing and Wavelength Assignment (RWA) mathematical model in WDM optical networks

In WDM networks, the end users exchange information with each other through all optical WDM channels, called light-paths. A light-path must occupy the same wavelength on all the fiber links through which it traverses. In a WDM optical network, with a given set of connections, the question of setting up light-paths by routing and allocating a wavelength to each connection is called Routing and Wavelength Assignment (RWA) problem. Integer Linear Programming (ILP) is a mathematical formulation helps in minimizing and maximizing an object function under multiple constraints. This can help in formulating a mathematical model for RWA. This paper studies a mathematical model for RWA in WDM Optical networks which can lead to a good network planning. This paper suggests an enhancement proposal for Syrian telecommunication optical networks using ILP formulation.

Evaluate the performance of a wide band LPDA antenna and compare it with a half-wavelength antenna at frequency change

Antennas have become an indispensable basic need, especially in the area of wireless networks, and have developed in the past few decades in a very large way in terms of profit and resistance, bandwidth, bandwidth, radiation pattern, etc. in line with new and increasing requirements. In this study, we are interested in studying a broad band antenna where this antenna is very important in systems that operate on a set of frequencies rather than at a fixed frequency. The traditional antennas that are designed at a specific frequency change their response significantly if used on a wide bandwidth around the designed frequency In this study, the LPDA (Log periodic dipole Array) antenna was designed and studied in a broadband field and compared to the antenna reference of wire antennas. It is a halfwavelength antenna λ/2. The study of the effect of frequency change in the antenna radiation pattern and the radiation beam Half-power level and front-to-back ratio (F/B).

Increasing the efficiency of the photovoltaic cell by Grooving its surface using laser

We grooved photovoltaic cell surface, to extend front grid electrical contact, using laser to improve its performance. By reduce line width leads to reduced shading loss. Mor light can penetrate into the cell instead of being reflected from the metallic gridlines.

The acoustic wave tilt angle effect on the interaction type and quality factor of the tunable acousto-optic filters

The acousto-optic filters that depend on the interaction technology between the optical and ultrasonic waves are considered a high- performance filters as they have the largest tuning range compared to other filters types. These filters can be used in optical WDM (Wavelength Division Multiplexing) networks. This work aims to study two types of these filters, one operates according to the non-collinear type of interaction, whereas the other type operates according to the quasicollinear type of interaction, and compare between these two filters types from the practical side. Thus, this work aims to show the tilt angle effect of the acoustic wave on the filter's design and its efficiency in electing the desired optical wave length, in addition to compare the frequency curves related to these angles in terms of their sensitivity to the changes of the incidence angle. The importance of this work lies in proving the efficiency of the filters operating according to the quasi-collinear type of interaction and their ability to achieve the high values of quality factor.

Development the performance Of Optical Network Units (ONU) by Polarization Division Multiplexing technique

This research proposes the development of Optical Network Units by introducing an all optical Filter. This optical filter can treat WDM and PDM technology at the same time enabling us to send a channel on the horizontal and vertical of the same wavelength .The hybrid WDM-PDM technology allows to delivery double channels for users without any changing in infrastructure between optical central office and user . Firstly , this article prove the idea of hybrid WDM-PDM technology by OptiSystem7.0 simulator, secondly we study proposed all optical Filter for three cases of optical access: WDMPDM( Downstream), WDM(Downstream)/( TDM(Upstream) , WDM(Downstream)/ WDM(Downstream) recommended by the international communication federation, ICF.

Modeling and Simulation of Acousto-Optic Tunable Filter For WDM Applications

Optical filter is one of the most accurate and important elements in pure optical communication network which uses wavelength division multiplexing (WDM). This research includes studying Acousto Optic Tunable Filter (AOTF) in linear anisotropic medium, which depends on the interaction principle between optical waves and acoustic waves. This paper describes simulating and testing the AOTF in MATLAB/Simulink software which is a strong tool for simulating and designing various systems. We have achieved an AOTF model, and created special block which could be added to MATLAB Simulink Library. We have also evaluated the performance of this filter and its ability to select one wavelength between the set combined by WDM. Moreover, we have studied the effect of acoustic wave frequency, its velocity, the properties of the crystal used in manufacturing it, and other influent parameters, along the selected wavelength.