Department of Electrical and Electronic Engineering

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About Department of Electrical and Electronic Engineering

Facts about Department of Electrical and Electronic Engineering

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48

Publications

49

Academic Staff

1292

Students

11769

Graduates

Programs

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B. Sc. in Control and Automation Engineering
Major Control and Automation Engineering

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B. Sc. in Electronic and Communication Engineering
Major Electronic and Communication Engineering

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Who works at the Department of Electrical and Electronic Engineering

Department of Electrical and Electronic Engineering has more than 49 academic staff members

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Dr. noreddin abdulsalam Ahmed abodhir

Publications

Some of publications in Department of Electrical and Electronic Engineering

Voice Quality Enhancement in VoIP Networks byReducing Packets Los

Abstract Voice over IP (VoIP) uses the Internet Protocol (IP) to transmit voice as packets over an IP network, like the Internet, Intranets and Local Area Networks (LAN). Here the voice signal is digitized, compressed and converted to IP packets and then transmitted over the IP network. However, at the receiving end, some packets may be missed in its way due to network congestion. This packets loss degrades the quality of speech at the receiving end of a voice transmission system in the IP network. Since the voice transmission is a real time process, the receiver cannot request for retransmission of the missing packets. High speed networks provide real time variable bit rate service with packet loss requirements. The burstiness of the correlated traffic makes dynamic buffer management highly desirable to satisfy the Quality of Service (QoS) requirements. This thesis presents an algorithm to improve and optimize the Adaptive Buffer Allocation Scheme to deal with input traffic based on loss of consecutive packets in data streams and buffer occupancy levels. Buffer is designed to allow the input traffic to be partitioned into different priority classes, and based on the input traffic behavior it controls the threshold dynamically. This scheme allows input packets to enter into buffer if its occupancy level is less than the threshold value for priority of that packet. The threshold is dynamically varied in runtime based on packet loss behavior. The performance evaluation is carried out using simulation and is carried out for two and multiple priority classes of the input traffic "real time and non real time classes". The simulation results show that the Modified Adaptive Partial Buffer Sharing (ADPBS) has better performance than Adaptive Partial Buffer Sharing under the same traffic conditions.
اسماء احمد الكيش (2010)
Publisher's website

تأثير سرعة حركة جهاز النقال على فشل التحويل الرأسي في شبكة الجيل الرابع المستقبلية للأجهزة النقالة

يُتوقع في شبكات الجيل الرابع المستقبلية للهاتف النقال بأن تدعم تقنية الشبكات اللاسلكية المحلية تقنية الشبكات الخليوية ذات التغطية الواسعة، و هذا ينتج عنه شبكات لاسلكية مهجنة مبنية على أساس بروتوكول الانترنت . على الرغم من أن تقنية الشبكات الخليوية ذات التغطية الواسعة كشبكة الجيل الثالث للهاتف النقال تسمح بإعطاء سرعات لنقل البيانات تصل إلى2 ميجابت، فهي تعتبر سرعات صغيرة عند مقارنتها بالسرعات المنجزة في التقنيات اللاسلكية الأخرى كالشبكة المحلية اللاسلكية التي تصل سرعتها إلى 54 ميجابت أو أكثر. بسبب ذلك تم عمل عدة سيناريوهات لربط هاتين الشبكتين المتكاملتين حيث أنّ الشبكة الخليوية من الجيل الثالث تعطي تغطية شاملة والشبكة المحلية اللاسلكية تعطي سرعات عالية لنقل البيانات. إنّ جهاز النقال يمكنه أن يحوّل بين هاتين الشبكتين عن طريق عملية تعرف بالتحويل الرأسي. إنّ المقدرة على توقيت عملية التحويل الرأسي أثناء عملية الاتصال من شبكة نظام معين إلى شبكة نظام آخر تعتبر من المتطلبات الهامة لتقليل احتمالية فشل التحويل وفقد البيانات أثناء التحويل. هذا المطلب الهام يجب أن يتحقق للأجهزة النقالة المتحركة عند سرعات مختلفة، من المترجلين إلى المركبات الآلية. في هذه الرسالة، تم تحليل تأثير سرعة حركة الجهاز النقال على التأخّر الزمني لكشف الحاجة لبدء عملية التحويل الرأسي ومن ثم على فشل هذا التحويل، وذلك باستخدام الطرق الرياضية. إضافة إلى ذلك تم استخدام الطرق الرياضية لتحليل تأثير سرعة حركة جهاز النقال وظاهرة تصادم الإشارات التنبيهية في الشبكة المحلية اللاسلكية على فشل التحويل الرأسي، كما تم إيضاح كيفية تعديل معدل ارسال الإشارات التنبيهية للأفضل، و ذلك لتقليل احتمالية فشل التحويل الرأسي مع تقليل سعة الشبكة المحلية اللاسلكية المحجوزة من قبل الإشارات التنبيهية. Abstract It is expected in fourth generation (4G) future mobile networks that WLAN technology will complement cellular wide area technology resulting in overlay hybrid networks based on IP protocol. Although cellular wide area technology such as the (UMTS) allows for data speeds of up to 2 Mbps, this is much less when compared to the data speeds achievable with other wireless network technology such as the IEEE 802.11 WLAN standards which can reach 54 Mbps. Because of that multiple scenarios have been made in order to integrate this two complementary networks : UMTS offers universal coverage and WLAN offers high connection data rate spots. The mobile terminal can switch from WLAN to cellular UMTS or vice versa by a process known as vertical handoff. The ability to timely process vertical handoffs, during communication sessions, from one network type to another will be an important requirement for minimizing handoff failure probability and data loss. This must be achieved for mobile terminals moving at various speeds from pedestrian’s speed to a fast moving vehicle’s. In this thesis, the effect of mobile terminal moving speed on vertical handoff detection delay and, hence, on vertical handoff failure is analytically studied. In addition, the effect of mobile terminal speed and beacon frame collision in WLAN on vertical handoff failure is analyzed through mathematical approach. Also it is shown how to optimize the beacon period in order to have minimum vertical handoff failure probability and minimum WLAN access point channel capacity occupied by beacon signals.
تامر تيسير حمدان (2009)
Publisher's website

Space-Time Block Coded Spatial Modulation Aided mmWave MIMO with Hybrid Precoding

In this paper, a combination of Space-Time Block Coded Spatial Modulation with Hybrid Analog-Digital Beamforming (STBC-SM-HBF) for Millimeter-wave (mmWave) communications is proposed in order to take advantage of the merits of Spatial Modulation (SM), Space-Time Block Codes (STBC), Analog Beamforming (ABF), and digital precoding techniques while avoiding their drawbacks. This proposed system benefits from the multiplexing gain of SM, from the transmit diversity gain of STBC, and from the Signal-to-Noise Ratio (SNR) gain of the beamformer. The simulation results demonstrate that the Zero Forcing (ZF) and the Minimum Mean Square Error (MMSE) precoded STBC-SM systems have better Bit Error Rate (BER) performance than the precoded SM systems. Moreover, the precoded SM shows a performance degradation compared to STBC-SM system. Furthermore, the BER is significantly improved by employing an array of ABF. In addition, it is demonstrated that a minimum of 2 antenna elements in the proposed scheme of STBC-SM-HBF are required to obtain better BER than that of the conventional SM and STBC-SM systems under the same spectral efficiency of 2 bits/s/Hz.
Taissir Y. Elganimi, Ali A. Elghariani(5-2018)
Publisher's website