National Telecommunication Institute NTI

Cairo, Egypt

National Telecommunication Institute NTI

Cairo, Egypt

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El-Hennawy H.M.,Ain Shams University | Gomaa H.H.,Ain Shams University | Amin A.S.,National Telecommunication Institute NTI
ICT 2010: 2010 17th International Conference on Telecommunications | Year: 2010

Internet Protocol version 6 (IPv6) is a new protocol that has been defined to ultimately replace IPv4. IPv6 solves the problem imposed by the limited 32-bit address field in IPv4. However the definition of the new protocol results in longer header size, which affects services that used to be transmitted over IP especially real-time services such as voice. As IP network is no longer confined to the wired domain and is being extended over wireless networks. The IEEE 802.16-based WiMAX (World Wide Interoperability of Microwave Access) promises to be one of the wireless access technologies capable of supporting very high bandwidth applications. In this paper, using the simulation results obtained by NS2, we demonstrate the effectiveness of transmitting voice traffic over IPv6 convergence sublayer of WiMAX mesh network and compare it with the quality in case of applying current header compression techniques, Robust Header Compression (ROHC) and Payload Header Suppression (PHS), and a new proposed modification to the PHS technique. We prove that using our proposed technique we improve the current PHS technique and approach the same performance of ROHC technique. © 2009 IEEE.

Said A.M.,Ain Shams University | Said A.M.,National Telecommunication Institute NTI | Marot M.,Telcom SudParis | Ibrahim A.W.,National Telecommunication Institute NTI | Afifi H.,Telcom SudParis
Computer Networks | Year: 2016

Vehicular Ad-Hoc Network (VANET) is an emerging technology, which provides intelligent communication between mobile vehicles. Integrating VANET with Ubiquitous Sensor Networks (USN) has a great potential to improve road safety and traffic efficiency. Most VANET applications are applied in real time and they are sensitive to delay, especially those related to safety and health. Therefore, checking the applicability of any proposed application is very important. One way to achieve that is by calculating the Round Trip Time (RTT), which is the time taken by a VANET application starting from the initiator node (source vehicle) sending a message until receiving a response from the core network. In this paper, we present a new complete analytical model to calculate the RTT of VANET applications. Moreover, we introduce a novel detailed network architecture for VANET applications using the IP Multimedia Subsystem (IMS) as a service controller in the USN environment. To the best of our knowledge, there is no previous published work that either studied the RTT of VANET applications or developed a complete architecture to implement them by integrating VANETs with USNs and IMS. The RTT is calculated by combining two analytical models. Firstly, we developed an analytical model to calculate the time needed for the communication between two nodes on a road. Secondly, we developed a queuing model using Baskett Chandy Muntz Palacios (BCMP) queuing network for the IMS servers to calculate the application's execution time in the core network. These models are general enough to be applied to any VANET application. Finally, to assess the validity and the accuracy of the proposed architecture and models, we used three different tools: C++, MATLAB, and OPNET. The analytical results were compared to the simulation results to evaluate their consistency. © 2016 Elsevier B.V. All rights reserved.

Ragheb A.N.,National Telecommunication Institute NTI | Fahmy G.A.,Electronics Dep. | Ashour I.,National Telecommunication Institute NTI | Ammar A.,Al - Azhar University of Egypt
ICIAS 2012 - 2012 4th International Conference on Intelligent and Advanced Systems: A Conference of World Engineering, Science and Technology Congress (ESTCON) - Conference Proceedings | Year: 2012

In this paper, a high, flat gain and low noise factor for a 3-11 GHz single ended ultra-wideband low noise amplifier (LNA) applications. The proposed LNA uses current reuse technique for low power consumption, high and flat gain. To achieve wideband input matching, the shunt-shunt resistive feedback and degenerative parallel LC technique are used. The output matching is achieved by using cascaded LC technique. The proposed LNA dissipates 8.65 mW under supply voltage of 1.2 V, achieves the input reflection S11 below 10.61 dB, while the output reflection S22 below 11.28 dB, the gain S21 14.44-15.76 dB, and the noise figure NF 2.7-3.38 dB. This LNA is designed and simulated by a TSMC 0.18 μ m process. © 2011 IEEE.

Said A.M.,National Telecommunication Institute NTI | Ibrahim A.W.,National Telecommunication Institute NTI | Soua A.,Telcom SudParis | Afifi H.,Telcom SudParis
Proceedings - International Conference on Advanced Information Networking and Applications, AINA | Year: 2013

Sensor networks suffer from limited capabilities such as bandwidth, low processing power, and memory size. There is therefore a need for protocols that deliver sensor data in an energy-efficient way to the sink. One of those techniques, it gathers sensors' data in a small size packet suitable for transmission. In this paper, we propose a new Effective Data Aggregation Protocol (DAP) to reduce the energy consumption in Wireless Sensor Networks (WSNs), which prolongs the network lifetime. This work uses in-network aggregation approach to distribute the processing all over the aggregation path to avoid unbalanced power consumption on specific nodes until they run out. Simulation results prove that DAP, compared to other protocols, achieves more data aggregation percentage and less power consumption for a one data harvesting round. © 2013 IEEE.

Farrag W.,Al - Azhar University of Egypt | Ragheb A.N.,National Telecommunication Institute NTI | Rashid N.,Al - Azhar University of Egypt
National Radio Science Conference, NRSC, Proceedings | Year: 2014

This paper presents a design of Low Noise Amplifier (LNA) for Cognitive Radios (CRs) receiver and it operates from 50 MHz to 5 GHz. The proposed design is consisted of two stages; the first one is a combination of cascode with common gate stage to improve the gain, power consumption, and the input matching. The second stage is a common source (CS) for cancelling the noise and distortion of CG of the first stage. This design achieves a noise figure 4.1-4.8 dB, input reflection coefficient less than-11 dB, output reflection coefficient below-10 dB, the power gain from 10.2 dB to 12.5 dB and the power consumption 7.14 mW supplied from 1 V. The proposed LNA is designed using 0.18 μm CMOS technology. © 2014 IEEE.

Said A.M.,National Telecommunication Institute NTI | Soua A.,U.S. National Institute of Standards and Technology | Abd-Elrahman E.,National Telecommunication Institute NTI | Abd-Elrahman E.,Orange Group | Afifi H.,Orange Group
IWCMC 2015 - 11th International Wireless Communications and Mobile Computing Conference | Year: 2015

Multi-modal traffic management in Intelligent Transportation Systems (ITS) aims to provide a more efficient traffic regulation to passengers and reduce congestion and obstruction in the roads. In spite of the outstanding progress made in this research filed; traffic management still a very challenging problem regarding the multiple factors that have to be taken into account in any proposed solution. To tackle this problem, this paper introduces a collaborative model based context awareness multi-modal traffic management aiming at providing an efficient way to manage the traffic inside a transportation station. In this model (Multi-Layers Stations: the stations that have different intersections for different means of transport), the traffic management is based on a Q-learning technique that takes into account the context awareness parameters to provide more potent decisions. The learning technique offers the opportunity to the system (transportation station) to adapt dynamically its decision (choice of the best transportation mean) based on feedbacks provided by the passengers traveling from that specified station and thus optimize their journey through the transportation network. The efficacy of our proposed technique is validated through extensive simulations for different layers of transport means like metros, trains, and buses. Our proposal holds for any ITS system decisions provided the availability of real-time traces about the passengers passing by any station. © 2015 IEEE.

Said A.M.,National Telecommunication Institute NTI | Ibrahim A.W.,National Telecommunication Institute NTI
2012 IEEE 14th International Conference on e-Health Networking, Applications and Services, Healthcom 2012 | Year: 2012

Sensor Networks are considered the heart of a wide range of applications. e-Health is one of those applications. This paper proposes a new network and Context Awareness service architecture for e-Health services. The proposal integrates the Ubiquitous Sensor Network (USN) with the IP Multimedia Subsystem (IMS)-based Next Generation Network (NGN). It provides a detailed signaling model for different healthcare scenarios based on SIP. The proposal involves modifications made to SIP to match the new e-Health features provided. © 2012 IEEE.

Eltaweel S.G.,National Telecommunication Institute NTI
2013 9th International Computer Engineering Conference: Today Information Society What's Next?, ICENCO 2013 | Year: 2013

In this paper, we have a mixture of two added images and it is required to separate the two image sources from the combined one after receiving the combined image and one of the two source images. The Discrete Wavelet Transform (DWT) is applied on the combined image. Also, it is applied on the corrupted and received image source. The high frequency components of the combined image and the image source are correlated. The result of correlation is used in classifying the pixel whether belongs to image source or zero. The experiment is applied on the other image source and the combined image. The performance is measured and compared to a recent paper in the same topic and the proposed method is proved to have better results than the results of the recent paper. In the recent paper, the color mixture is not considered, it is considered in our work and gave very good results. © 2013 IEEE.

Eltaweel S.G.,National Telecommunication Institute NTI
ICENCO'2011 - 2011 7th International Computer Engineering Conference: Today Information Society What's Next? | Year: 2012

In this paper a new technique is introduced to hide nine images in a color image. The color image has size four as the watermark size. In each of the color image components three images are hidden. Each color component is decomposed by a Discrete Wavelet Transform (DWT) into four components. Three of four components are used to hide the three images. The hiding operation starts with taking the Discrete Cosine Transform (DCT) for the watermark and the result is multiplied by a factor and added to a component of the three components which result from the DWT decomposition. The Inverse DWT (IDWT) is applied to reconstruct the red, green and blue components. Finally, the result is the reconstruction from the main components. The extraction process is considered in the theory of statistical signal processing as a correlation receiver. The correlation is calculated to decide each pixel is a watermark pixel or not. Different types of images are used as watermarks. The results show the robustness of the technique, the SNR obtained is at least 25 dB. © 2011 IEEE.

El Zorkany M.,National Telecommunication Institute NTI
Advances in Intelligent Systems and Computing | Year: 2014

Image and video transmissions require particularly large bandwidth and storage space. Image compression technology is therefore essential to overcome these problems. Practically efficient compression systems based on hybrid coding which combines the advantages of different methods of image coding have also being developed over the years. In this paper, different hybrid approaches to image compression are discussed. Hybrid coding of images, in this research, deals with combining three approaches to enhance the individual methods and achieve better quality reconstructed images with higher compression ratio. In this paper A new Hybrid neural-network, vector quantization and discrete cosine transform compression method is presented. This scheme combines the high compression ratio of Neural network (NN) and Vector Quantization (VQ) with the good energy-compaction property of Discrete Cosine Transform(DCT). In order to increase the compression ratio while preserving decent reconstructed image quality, Image is compressed using Neural Network, then take the hidden layer outputs as input to re-compress it using vector quantization (VQ), while DCT was used the code books block. Simulation results show the effectiveness of the proposed method. The performance of this method is compared with the available jpeg compression technique over a large number of images, showing good performance. © Springer International Publishing Switzerland 2014.

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