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Article
Traffic Offloading in LTE System Based Heteroge-neous Networks

Author: Mahmood F. Mosleh
Journal: Iraqi Journal for Electrical And Electronic Engineering المجلة العراقية للهندسة الكهربائية والالكترونية ISSN: 18145892 Year: 2017 Volume: 13 Issue: 2 Pages: 152-160
Publisher: Basrah University جامعة البصرة

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Abstract

The continuous growing developments in the traffic of mobile data limits the data throughput and capacity of cellular networks. “Heterogeneous Networks (HetNets)” are efficient solution to realize such demands. However, in HetNets, the congestion on the overloaded cellular network can be increased when the traffic of data is pushed from a cellular network to the Wi-Fi. In practice, offloading the cellular data traffic to a Wireless Local Area Network (WLAN) depending on the signal quality is a broadly deployed method to solve such problem. The use of Device to Device (D2D) communication further enhances the traffic offloading in WLAN systems and helps to obtain better throughput, end-to-end delay and network load. However, the critical offloading potential and its impacts on the whole performance is not totally understood. In this paper, the offloading of Long Term Evolution (LTE) traffic is presented using a WLAN for voice and video applications. A comparison is performed among two WLAN mecha-nisms; Distributed coordination function (DCF) and Point Coordination Function (PCF). As well, the effect of add-ing a D2D technology to the PCF is discussed. The WLAN effectively offloaded nodes at their Signal to Interference and Noise Ratio (SINR) becomes more than a specific threshold. Results presented that the PCF mechanism outper-forms the DCF one in terms of packet loss ratio, throughput and the maximum load of the entire network. In addi-tion, the use of a D2D serviced in the PCF helps in further reduction in the network load.

Keywords

HetNets --- offloading --- LTE --- WLAN --- DCF --- PCF --- D2D --- SINR


Article
Hardware Implementation of Wireless Sensor Network Using Arduino and Zigbee Protocol

Authors: Mahmood F. Mosleh --- Duaa SH. Talib
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 5 Part (A) Engineering Pages: 816-829
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This paper presents a designed and implemented Wireless Sensor Network (WSN) based on Arduino and IEEE 802.15.4/Zigbee standards. This network consists offour end nodes; each one is connected to an individual type of sensors (lighting, temperature, motion, and distance) to form a safety network for building offices, factories, homes…etc. Also there is a fifth node in this network to collect the information from each node and send it to the base station which is a computer to be process the data and take the appropriate decision according to the program established by the user. Results confirmed that the network performs its functions with high efficiency and gave accurate readings of the surrounding circumstances. Stable reading of temperature and lighting had been achieved in the implemented network. Also, the motion and distance sensors gave good results depending onthe presence ofobjectsclose tothemore peoplemovingnear. In addition, the network is characterized by high flexibility and ease of programing that can be used to give various applications such aswarning of fire by setting a threshold level of temperature to enable an alarm when exceeding such level. It can also be used to preventtheftsbydetectingmovements ofthe humanbody with distance sensor. Inaddition, other uses can be implemented such as controlling heating and lightingdevicesin homes andotherbuildings.

Keywords

WSN --- Arduino --- IEEE 802.15.4/Zigbee


Article
Design and Implementation of WLAN Based ZigBee for Personal Identification

Authors: Mahmood F. Mosleh --- Zahraa I. Saber
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 8 Part (A) Engineering Pages: 919-924
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this research, a novel Wireless Local Area Network (WLAN) that can be used for personal identification has been proposed in order to control the entering of any building or facility for safety applications. The network consists of three parts; node carrying by authorized persons, Base Station (BS) to control the entering and gate controller. A Personal Computer (PC), which represented the BS, will display automatically some information like picture and state about the person that entered when he/she becomes in BS coverage area. The gate controller of protected building is received a command of PC after matching the data onto entire person and open by a period to allow only one person to pass the gate after being sensed by Human sensor of controller. While preventing any other body by maintaining the gate in case of closure and show alarm. For the experimental purpose, the control of the gate is virtually assumed as Light-Emitting Diode (LED) to represent the opening and closing by lighting and closing the LED respectively. An Arduino Uno is used as microcontroller and ZigBee S2 is used for communication link, because of their simplicity, small size and low cost. Results of running the proposed model confirmed that it could effectively and accurately control the entry and exit of people authorized to enter the important formation and recording the date and time of entry and exit form the need for intervention by people. On the other hand, it can easily review any person files and show his/her daily attendance.


Article
Reliable of High Data Rate Using Spatial Multiplexing and Convolution Code
بيانات بمعدل عالي وموثوقة باستخدام نظام متعدد المكانية مع المشفر الالتفافي

Authors: Eman A. Farhan --- Raad H --- Mahmood F. Mosleh
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2015 Volume: 33 Issue: 5 Part (A) Engineering Pages: 1189-1201
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Spatial Multiplexing (SM) can be achieved higher transmission rate without allocating higher bandwidth or increasing transmit power, so it is wildly used recently to serve the extremely demand of mobile communications. But multipath fading is major bottleneck in increasing the data rate and reliability of transfer of information over wireless channel. SM suffers from significant degradation in term of Bit Error Rate (BER) in such environments. In this research it has been tested a SM system with three types of detection. The first results show the Maximum Likelihood (ML) is the better one, but the complexity is increased dramatically with increasing of data rate or the level modulation order in addition of delay time. On the other hand, Zero Forcing (ZF) is very simple related to ML and it suitable for real time communications, but the problem is the Bit Error Rate (BER) is very high related to the performance of ML. So that this research proposed to adopt ZF decoder, and to support its performance, Convolutional Codes (CC) is added to this system to overcome this problem. The results show the proposed scheme gives a gain of about 10 dB of Signal to Noise Ratio (SNR) at BER of 10-4 for code rate of ½ of CC. To reduce the redundancy informations of CC, 2/3 code rate is proposed instead of ½. The results illustrates such system gives significant gain at high SNR, but the problem is the BER in increased up to system with code at low SNR. Also the results confirm that this problem decreases with high number of antennas. So that MIMO system is suitable for high data rate.

في هذا البحث تم اختبار نظام متعدد الادخال متعدد الاخراج (MIMO) باستخدام ثلاثة انواع من الكواشف. النتائج الاولية بينت ان افضل اداء يكون مع الكاشف القريب الاكبر (ML) لكن التعقيد يزداد في هذا النوع من بشكل واضح مع زيادة مستوى التضمين او زيادة سرعة البيانات. من ناحية اخرى فان الكاشف نوع الدفع الصفري (ZF) هو ابسط في التركيب قياسا الى ML كما انه مناسب لظروف الزمن الحقيقي في الاتصالات لكن مشكلته يعاني من نسبة خطأ(BER) عالية. لذلك اعتمد البحث هذا النوع من الكاشف واقترح اضافة مشفر من النوع الالتفافي (CC) لمعالجة هذه المشكلة. النتائج اوضحت بان التركيب المقترح حصل على ربح بحدود 10dB من نسبة الاشارة الى الضوضاء (SNR) عند BER=10-4 عند معدل تشفير1/2. ولغرض تقليل البيانات الخاصة بالمشفر تم اقتراح معدل تشفير 2/3 بدلا من ½. النتائج بينت ان هذا التركيب يعطي ربح واضح عند SNR العالية لكن المشكلة هو زيادة معدل الخطأ عند SNR الواطئة. لكن النتائج بينت ان هذه المشكلة تقل مع زيادة عدد الهوائيات. لذلك فان نظام MIMO مناسب للبيانات العالية.


Article
Size Miniaturized Fractal Nested Circular Rings-Shaped Microstrip Antenna for Various Wireless Applications

Authors: Shereen A. Shandal --- Mahmood F. Mosleh --- Mohamed A. Kadim
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 11 Part (A) Engineering Pages: 1176-1184
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this paper; a wideband fractal circular rings shapedmicrostrip antenna over partial rectangular ground plane is presented.Fractal geometry technique is used in order to take advantage of its selfsimilarproperty which lead to attain not only size miniaturization butalso wider bandwidth and iteration method is utilized that reach up tothird iteration. The proposed model is simulated by High FrequencyStructural Simulator (HFSS) package. Such model is designed on FR4substrate with a compact size of (20×18×1.5) mm3, 4.3 permittivity and0.02 loss tangent. The microstrip line feed is used to feed this antennawith a length of 4.65mm and width of 3mm, in order to increase theimpedance bandwidth of proposed model to 67.64%. This model isdesigned to operate at a range of frequency (4.5-9.1) GHz with tworesonant frequencies at 5.6GHz and 8GHz. The length of ground planeLg is optimized for enhance antenna parameters such as input reflectioncoefficient and Bandwidth. The simulation results show that the inputreflection coefficient values are -54.5 dB and -46.5 dB at two resonantfrequencies 5.6GHz and 8GHz. Also, radiation efficiency of proposedantenna is 97.29% with peak gain of 4.34dB. This antenna is appropriatefor various wireless Applications such as satellite communication,weather radar, (Industrial Scientific Medical) ISM band and (WirelessFidelity) Wi-Fi

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