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Two-level scheduling scheme for integrated 4G-WLAN network Mohammed Qasim Taha; Zaid Hussien Ali; Abdullah Khalid Ahmed
International Journal of Electrical and Computer Engineering (IJECE) Vol 10, No 3: June 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (799.399 KB) | DOI: 10.11591/ijece.v10i3.pp2633-2643

Abstract

In this paper, a novel scheduling scheme for the Fourth Generation (4G)-Wireless Local Area Network (WLAN) network is proposed to ensure that end to end traffic transaction is provisioned seamlessly. The scheduling scheme is divided into two stages; in stage one, traffic is separated into Actual Time Traffic (ATT) and Non-Actual-Time Traffic (NATT), while in stage two, complex queuing strategy is performed. In stage one, Class-Based Queuing (CBQ) and Deficit Round Robin (DRR) are used for NATT and ATT applications, respectively to separate and forward traffic themselves according to source requirements. Whereas in the stage, two Control Priority Queuing (CPQ) is used to assign each class the appropriate priority level. Evaluation of the performance of the integrated network was done according to several metrics such as end-to-end delay, jitter, packet loss, and network’s throughput. Results demonstrate major improvements for AT services with minor degradation on NAT applications after implementing the new scheduling scheme.
Analysis of the hard and soft shading impact on photovoltaic module performance using solar module tester Mustafa Hamid Al-Jumaili; Ahmed Subhi Abdalkafor; Mohammed Qasim Taha
International Journal of Power Electronics and Drive Systems (IJPEDS) Vol 10, No 2: June 2019
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (410.125 KB) | DOI: 10.11591/ijpeds.v10.i2.pp1014-1021

Abstract

Solar cells are a major alternate source of sustainable energy in the usual condition of depleting non- renewable energy sources. Nowadays, this source is getting more and more important due to its use in large and small-scale installations. One of the major causes of energy losses in photovoltaic (PV) modules is the shading. It can happen due to clouds passing, near trees, and/or neighboring structures. Generally, there are two types of PV module Shading which are either partial shading or complete shading. Both have a significant impact on the solar module output power. This paper is an attempt of carrying out a study of the electrical characteristics of a solar module with various percentages of simulated shading. The solar module tester (SMT) simulator was used in this study. The study approved the direct correlation between short-circuit current and solar irradiance. The advantage of using SMT is its stable irradiance in comparison to the practical unstable solar irradiance within the same period. The results of both methods of shading simulation show that shading has a significant impact on the performance of solar panel in terms of efficiency, fill factor and output power. For better performance, solar panels should install in shading free places as much as its possible.