Dr.Hesham ElBadawy | National Telecommunication Institute (original) (raw)

Papers by Dr.Hesham ElBadawy

Sensors

The work on perfecting the rapid proliferation of wireless technologies resulted in the developme... more The work on perfecting the rapid proliferation of wireless technologies resulted in the development of wireless modeling standards, protocols, and control of wireless manipulators. Several mobile communication technology applications in different fields are dramatically revolutionized to deliver more value at less cost. Multiple-access Edge Computing (MEC) offers excellent advantages for Beyond 5G (B5G) and Sixth-Generation (6G) networks, reducing latency and bandwidth usage while increasing the capability of the edge to deliver multiple services to end users in real time. We propose a Cluster-based Multi-User Multi-Server (CMUMS) caching algorithm to optimize the MEC content caching mechanism and control the distribution of high-popular tasks. As part of our work, we address the problem of integer optimization of the content that will be cached and the list of hosting servers. Therefore, a higher direct hit rate will be achieved, a lower indirect hit rate will be achieved, and the ...

British Journal of Dermatology, 2011

Terminally differentiating keratinocytes actively synthesize and accumulate cholesterol, which is... more Terminally differentiating keratinocytes actively synthesize and accumulate cholesterol, which is a key constituent of intercellular lipid lamellae which contribute to the epidermal permeability barrier. While the pathway for cholesterol biosynthesis is established, intracellular transport mechanisms for this lipid are poorly understood, despite their importance in regulating organelle sterol content, keratinocyte differentiation status and the activity of lipid-responsive transcription factors involved in skin health, repair and disease. Recent data implicate proteins containing a steroidogenic acute regulatory protein (StAR)-related lipid transfer (START) domain in cellular cholesterol homeostasis. To investigate gene expression of cytosolic, cholesterol-binding StAR-related lipid transfer domain 4 (STARD4) protein in primary human keratinocytes and differentiating HaCaT keratinocytes and, by overexpression of this protein, the function of STARD4 in HaCaT keratinocyte lipid phenotype and differentiation status. Quantitative polymerase chain reaction was utilized to measure gene expression of STARD4 relative to the housekeeping gene GAPDH. Following transient (48 h) overexpression of STARD4, keratinocyte lipid mass and lipogenesis were measured, along with expression of genes involved in cholesterol homeostasis and those encoding a range of keratinocyte differentiation markers. Cholesterol-binding protein STARD4 is expressed in both primary and immortalized HaCaT keratinocytes, and is repressed during Ca(2+) -dependent differentiation of the latter. Transient overexpression of STARD4 reduces endogenous [(14) C]cholesterol and cholesteryl ester biosynthesis, and triggers increased expression of SREBF2, ABCG4 and LOR, while repressing expression of ABCA1. The cytosolic cholesterol-sensing protein STARD4 modulates both keratinocyte cholesterol homeostasis and differentiation status, increasing the efficiency of cholesterol trafficking within the cell, and amplifying and &amp;amp;amp;#39;fine-tuning&amp;amp;amp;#39; cellular responses to this sterol. Modulation of expression of STARD4, and other members of the START family of lipid trafficking proteins, may prove useful in resolving imbalances in lipid metabolism associated with loss of epidermal barrier function in psoriasis and atopic dermatitis.

2022 39th National Radio Science Conference (NRSC)

2020 International Workshop on Antenna Technology (iWAT)

5G New Radio (NR) is becoming an increasingly interesting topic in the field of mobile communicat... more 5G New Radio (NR) is becoming an increasingly interesting topic in the field of mobile communications. It requires to fulfill the requirements of better quality of service and high data rate for the wireless applications. 5G antennas are required to have a small size to fit into smart phones and to cover the maximum band of operation. In this paper, different techniques are introduced that maximize the band of operation whilst keeping the antenna size to minimal, and an antenna is proposed that covers the frequency band 1.24 - 5GHz except for the band 2.3 - 3 GHz of the 4G/5G NR bands.

IEEE Access, 2022

Mobile Edge Computing (MEC) technology philosophy inspires the next generation mobile networks to... more Mobile Edge Computing (MEC) technology philosophy inspires the next generation mobile networks to provide cloud computing capabilities in addition to a diverse range of Information Technology (IT) services with ultra-low latency and higher bandwidth at the edge. One of the most common challenges of 5G-MEC is the management and orchestration across all networks and infrastructure resources as well as end-to-end quality of experience. The decentralized architecture of MEC with independent and non-collaborative servers results in the situation of having underutilized servers with wasted energy. Moreover, the consequences of having highly utilized servers with highly consumed energy are not only the incapability to accommodate all the load of the computing jobs and the dramatic increase in the total OPEX cost, but it also creates some environmental problems. Orchestrating servers' workload and control offloading the computation jobs is one of the technical advantages of MEC since it satisfies the increasing requirements of modern mobile applications while optimizing the energy consumption and cost. In this work, we consider cluster-based energy-aware offloading framework. The proposed work consists of dual-tier domain divided into clusters of Edge Servers ES s. We have presented the results of our simulation as a proof of our concept that the formulated adaptive strategy to minimize the optimization problem calculation per cluster reduces the energy consumption and enhances the quality of experience while achieving the conservation of the related computing and storage resources cost. INDEX TERMS MEC, IT, 5G, OPEX (operating expense), edge servers.

In this paper, an adaptive polarized Multiple-Input Multiple-Output (MIMO) Multicarrier Spread Sp... more In this paper, an adaptive polarized Multiple-Input Multiple-Output (MIMO) Multicarrier Spread Spectrum Code Division Multiple Access (MC-SS-CDMA) system is designed for downlink mobile communications. The proposed system will be examined in Frequency Division Duplex (FDD) mode for both macro urban and suburban environments. For the same transmission bandwidth, a performance comparison between both nonoverlapped and orthogonal Frequency Division Multiplexing (FDM) schemes will be presented. Also, the proposed system will be compared with both the closed loop vertical MIMO MC-SS-CDMA system and the synchronous vertical STBC-MIMO MC-SS-CDMA system. As will be shown, the proposed system introduces a significant performance gain as well as reducing the spatial dimensions of the MIMO system and simplifying the receiver implementation. The effect of the polarization diversity characteristics on the BER performance will be discussed. Also, the impact of excluding the cross-polarization MCS...

International Journal of Sciences: Basic and Applied Research, 2016

VoLTE (Voice over LTE) is a solution to transfer voice packets over the LTE network, with low lat... more VoLTE (Voice over LTE) is a solution to transfer voice packets over the LTE network, with low latency and high QoS (Quality of Service). As the efficient QoS assessment of VoLTE service is a crucial item for LTE networks operators and there are no studies were performed on commercial networks, and almost all previous studies’ conclusions were built on simulation tools ,this study provided detailed methods to calculate the required band widths for different VoLTE bearers and showed how to configure these bandwidths on different VoLTE network nodes practically .To verify the network performance, a real VoLTE traffic packets were collected from a commercial VoLTE network. By inspecting these logs, a novel standard mathematical method will be used to calculate the different QoS KPIs (Key Performance Indicators) such as Round trip Delay, Packet loss Rate (PLR), Jitter and MOS (mean Opinion Score) which were taken as performance metrics for design verification by comparing the calculated ...

JES. Journal of Engineering Sciences, 2012

The convergence of heterogeneous wireless networks combines existing wireless networks. An effect... more The convergence of heterogeneous wireless networks combines existing wireless networks. An effective combination of different wireless networks should enable them to complement each other and provide high-speed data rate, wide area coverage, and quality of service (QoS) guarantee. In Next Generation Wireless Systems (NGWS), seamless handoff between different wireless access networks plays a vital role. One of the major challenges for seamless mobility is the creation of a vertical handoff protocol. In this paper, the performance of vertical handoff is studied using the integration of third generation (3G) cellular and wireless local area networks (WLAN). The effect of application-based signal strength threshold (ASST) and path loss exponent on an adaptive lifetime-based vertical handoff (ALIVE-HO) strategy is studied in terms of number of handoffs, aggregated throughput, and packet delay. Therefore the vertical handoff performance can be optimized in wireless and mobile networks. The present work is done for different channel conditions as well as different mobility schemes.

Journal of Physics: Conference Series, 2020

Nowadays, the Non-Orthogonal Multiple Access (NOMA) has become the most candidate as the multiple... more Nowadays, the Non-Orthogonal Multiple Access (NOMA) has become the most candidate as the multiple access technique for the Fifth Generation (5G). Although, the massive increase in traffic usage is necessary, but it must not come on the account of Energy Efficiency (EE). Therefore, Green Radio (GR) which one of its main points is energy efficiency (EE) gained a lot of attention in last few years in both academic and industrial fields. In this paper, the Energy-Efficiency in the NOMA downlink system under the effect of the Nakagami-m fading channel is studied. Moreover, the Nakagami-m fading channel can tackle several fading cases according to the parameter m. The system has been solved via an iterative algorithm to investigate the required power level for maximum energy efficiency. Different channel models will be investigated such as: one-sided Gaussian faded channel, Rayleigh faded channel, Raician (Nakagami-n) faded channel, and LOS.

Sensors, 2019

The demand for extensive data rates in dense-traffic wireless networks has expanded and needs pro... more The demand for extensive data rates in dense-traffic wireless networks has expanded and needs proper controlling schemes. The fifth generation of mobile communications (5G) will accommodate these massive communications, such as massive Machine Type Communications (mMTC), which is considered to be one of its top services. To achieve optimal throughput, which is considered a mandatory quality of service (QoS) metric, the carrier sense multiple access (CSMA) transmission attempt rate needs optimization. As the gradient descent algorithms consume a long time to converge, an approximation technique that distributes a dense global network into local neighborhoods that are less complex than the global ones is presented in this paper. Newton’s method of optimization was used to achieve fast convergence rates, thus, obtaining optimal throughput. The convergence rate depended only on the size of the local networks instead of global dense ones. Additionally, polynomial interpolation was used t...

IET Communications, 2018

A hybrid overlay/underlay cognitive radio network (CRN) is demonstrated to provide high spectrum ... more A hybrid overlay/underlay cognitive radio network (CRN) is demonstrated to provide high spectrum efficiency and channel capacity. Decision-making in joining CRNs is one of the major issues of secondary users (SUs). Each SU has the option of joining the spectrum or balking according to the trade-off between the service profit and the delay cost. In this study, the decision-making problem in accessing the hybrid overlay/underlay CRN is addressed using queuing models and game theory. An almost unobservable queuing server is used to model hybrid overlay/underlay CRN. The interaction between the cognitive users is treated as a non-cooperative game. A closed-form expression for the average number of cognitive users as well as associated expected waiting time in both overlay and underlay CRNs is derived. The strategic behaviour for spectrum access of cognitive users in hybrid overlay/underlay CRN is investigated and the existence of symmetric Nash equilibrium is proved as well. Finally, we provide extensive validation results using a wide range of realistic simulation scenarios. The proposed model gives detailed guidance to the decision makers to deploy the suitable strategy according to the available channel situation.

As the power consumption is an essential issue for designers of mobile devices The 3 rd Generatio... more As the power consumption is an essential issue for designers of mobile devices The 3 rd Generation Partnership Project (3GPP) - Long Term Evolution (LTE) employs a multicarrier communication technique on the air interface, Single Carrier Frequency Division Multiple Access (SC- FDMA), in uplink scenario and Orthogonal Frequency Division Multiple Access (OFDMA) in the downlink. SC- FDMA core modulation technology has a significantly lower Peak to Average Power Ratio (PAPR) compared to OFDMA. This paper studies the PAPR reduction techniques for LTE SC-FDMA system.

2008 International Conference on Computer and Communication Engineering, 2008

Nowadays, a lot of radio access technologies (RAT) have been deployed. In order to achieve a seam... more Nowadays, a lot of radio access technologies (RAT) have been deployed. In order to achieve a seamless integration between these different RATs, common radio resource management (CRRM) algorithms are considered to be deployed in such heterogeneous wireless networks. This paper provides a complete analytical approach to determine the performance of different RAT with selection procedures in multi-RAT/multi-service environment. Particularly, multi-dimensional