arXiv subjects

Jaafar M. H. Elmirghani

Publications and source records attributed to Jaafar M. H. Elmirghani.

At least 109 records · Page 6Linked to original sources

arXiv2020

Shared optical wireless cells for in-cabin aircraft links

The design of a wireless communication system that can support multiple users at high data rates inside an aircraft is a key requirement of aircraft manufacturers. This paper examines the design of an on-board visible light communication (VLC) system for transmitting data on board Boeing 747-400 aircraft. The reading light unit of each seat is utilised as an optical transmitter. A red, yellow, green, and blue (RYGB) laser diode (LD) is used in each reading light unit for transmitting data. An angle diversity receiver (ADR), which is an optical receiver that is composed of four branches (in this work), is evaluated. The signal-to-interference-plus-noise ratio (SINR) and data rate are determined. Three scenarios have been examined where, in the first scenario, one device is used, in the second scenario two devices are used and in the third scenario three devices are used by each passenger. The proposed system can offer high SINRs that support high data rates for each passenger by using simple on-off-keying (OOK).

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arXiv2020

Energy Efficient Cloud-Fog Architecture

The advancements of cloud computing came as a radical transformation in the way Information and Communication Technology (ICT) services are deployed and maintained. Cloud computing provides ubiquitous on-demand access to an Internet-based pool of processing, storage, and communication resources offered to a large set of geographically distributed users. As the cloud computing infrastructure grows and demand increases, the need for a new breed of on-demand computing that can efficiently maintain Quality of Service (QoS) requirements has increased. Fog computing was proposed to address the limitations of cloud computing, in terms of delay and high bandwidth requirements, by extending the on-demand resources of clouds to the edge of the network bringing them closer to the users. The massive growth and wide use of cloud-fog services have created serious power consumption concerns. This article delves into the energy consumption of cloud-fog services by raising headline questions related to; how significant the problem itself is, how different conditions/scenarios affect the energy consumption of the architecture, and how to orchestrate the use of the architecture in an energy-efficient manner. We start by summarizing the cloud-fog architecture including different communication and computing layers. Additionally, we give a brief overview of the role of Virtual Machine (VM) placement in optimally using cloud-fog resources in a dynamic manner. Then, we present the problem of energy efficient VMs placement and provide numerical results.

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arXiv2020

Energy Efficient Virtual Machines Placement over Cloud-Fog Network Architecture

Fog computing is an emerging paradigm that aims to improve the efficiency and QoS of cloud computing by extending the cloud to the edge of the network. This paper develops a comprehensive energy efficiency analysis framework based on mathematical modeling and heuristics to study the offloading of virtual machine (VM) services from the cloud to the fog. The analysis addresses the impact of different factors including the traffic between the VM and its users, the VM workload, the workload versus number of users profile and the proximity of fog nodes to users. Overall, the power consumption can be reduced if the VM users traffic is high and/or the VMs have a linear power profile. In such a linear profile case, the creation of multiple VM replicas does not increase the computing power consumption significantly (there may be a slight increase due to idle / baseline power consumption) if the number of users remains constant, however the VM replicas can be brought closer to the end users, thus reducing the transport network power consumption. In our scenario, the optimum placement of VMs over a cloud-fog architecture significantly decreased the total power consumption by 56% and 64% under high user data rates compared to optimized distributed clouds placement and placement in the existing AT&T network cloud locations, respectively.

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arXiv2019

Impact of the Net Neutrality Repeal on Communication Networks

Network neutrality (net neutrality) is the principle of treating equally all Internet traffic regardless of its source, destination, content, application or other related distinguishing metrics. Under net neutrality, ISPs are compelled to charge all content providers (CPs) the same per Gbps rate despite the growing profit achieved by CPs. In this paper, we study the impact of the repeal of net neutrality on communication networks by developing a techno-economic Mixed Integer Linear Programming (MILP) model to maximize the potential profit ISPs can achieve by offering their services to CPs. We focus on video delivery as video traffic accounts for 78% of the cloud traffic. We consider an ISP that offers CPs different classes of service representing typical video content qualities including standard definition (SD), high definition (HD) and ultra-high definition (UHD) video. The MILP model maximizes the ISP profit by optimizing the prices of the different classes according to the users demand sensitivity to the change in price, referred to as Price Elasticity of Demand (PED). We analyze how PED impacts the profit in different CP delivery scenarios in cloud-fog architectures. The results show that the repeal of net neutrality can potentially increase ISPs profit by a factor of 8 with a pricing scheme that discriminates against data intensive content. Also, the repeal of net neutrality positively impacts the network energy efficiency by reducing the core network power consumption by 55% as a result of suppressing data intensive content compared to the net neutrality scenario.

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arXiv2019

Transmitter Diversity with Beam Steering

Providing high data rates is one of the drivers in visible light communication (VLC) systems. This paper introduces a VLC system that employs transmitters diversity with beam steering to provide high data rates. In this work, red, yellow, green, and blue (RYGB) laser diodes (LD) are used as transmitters to obtain a high modulation bandwidth. Two types of RYGB LDs units are used in this paper: transmitters diversity (TD) RYGB LDs light unit (for illumination and communication) and RYGB LDs light unit (for illumination). In addition, a seven branch angle diversity receiver (ADR) is used where we study the delay spread and SNR. The proposed system was compared to the normal VLC system. A data rate up to 22.8 Gb/s was achieved using simple on-off-keying (OOK) modulation.

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arXiv2019

Infrared uplink design for visible light communication (VLC) systems with beam steering

Providing uplink high data rate is one of the big concerns in visible light communication (VLC) systems. This paper introduces an uplink VLC system based on an infrared transmitter with beam steering to provide high data rates. In this work, a 4 branches angle diversity receiver (ADR) is used and the resultant delay spread and SNR are examined. The proposed system achieved data rates up to 3.57 Gb/s using simple on-off-keying (OOK).

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arXiv2019

Optical Wireless cabin communication system

Offering a high data rate to users inside the cabin is attractive for the aircraft building companies. This paper presents an optical wireless system that uses visible light for transmitting data. The reading light for each seat is used as a transmitter in this work to offer high data rates. Red, yellow, green, and blue (RYGB) laser diode (LD) are utilised in each reading light to obtain a high modulation bandwidth. Two types of reading lights based on angle diversity transmitter (ADT) units are utilised in this paper for illumination and communication. Additionally, two kinds of optical receivers are used: four branches angle diversity receiver (ADR) and 25 pixels imaging receiver (ImR). The delay spread and the signal to interference and noise ratio (SINR) are evaluated. The proposed system can offer high data rates up to 22.8 Gbps for each user by using simple on-off-keying (OOK) modulation.

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arXiv2019

Co-existence of Micro, Pico and Atto Cells in Optical Wireless Communication

Interference between cells or users can have a significant impact on the quality of optical wireless communication (OWC) links. This paper studies the co-existence of infrared based Micro cells with Visible light communication based Pico and Atto Cells for downlink communication. The signal to noise ratio (SNR) of each cell and the signal to interference and noise ratio (SINR) between cells are evaluated when an angle diversity receiver and an imaging receiver are used. The results show that Atto cell systems provide higher SNR and data rates compared to the Pico cell systems which provide higher SNR and data rates compared to Micro cell systems. The Micro cell systems however provide mobility as they provide a larger coverage area, followed by the Pico cell systems.

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arXiv2019

Resilient Service Embedding In IoT Networks

The Internet of Things (IoT) has been applied to a large number of heterogeneous devices and is used in the deployment of a variety of applications on the basis of its distributed open architecture. The majority of these IoT devices are battery-powered and are interconnected via a wireless network. IoT devices may be used to carry out critical tasks. Thus, the IoT network requires a resilient architecture that supports semantic search, failure discovery, data recovery, and dynamic and autonomous network maintenance. In this paper, we present a new resilience scheme for IoT networks. We evaluate the proposed scheme in terms of its power consumption and data delivery time, and then compare the results with those of recent resilience schemes such as schemes based on redundancy and replication. The proposed framework was optimized using mixed integer linear programming and real-time heuristics were developed, thus embedding a virtual layer into a physical layer based on a service-oriented architecture (SOA). The proposed framework offers different combinations of packet resilience in terms of recovering the lost data by using end- to-end mechanisms. We further analyzed these schemes by investigating the power consumption, data delivery time, and network overhead of these techniques. The results showed that the proposed splitting technique enhanced the network performance by reducing the power consumption and the data delivery time of service embedding by selecting energy-efficient nodes and routes in IoT networks.

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arXiv2019

A Survey of Big Data Machine Learning Applications Optimization in Cloud Data Centers and Networks

This survey article reviews the challenges associated with deploying and optimizing big data applications and machine learning algorithms in cloud data centers and networks. The MapReduce programming model and its widely-used open-source platform; Hadoop, are enabling the development of a large number of cloud-based services and big data applications. MapReduce and Hadoop thus introduce innovative, efficient, and accelerated intensive computations and analytics. These services usually utilize commodity clusters within geographically-distributed data centers and provide cost-effective and elastic solutions. However, the increasing traffic between and within the data centers that migrate, store, and process big data, is becoming a bottleneck that calls for enhanced infrastructures capable of reducing the congestion and power consumption. Moreover, enterprises with multiple tenants requesting various big data services are challenged by the need to optimize leasing their resources at reduced running costs and power consumption while avoiding under or over utilization. In this survey, we present a summary of the characteristics of various big data programming models and applications and provide a review of cloud computing infrastructures, and related technologies such as virtualization, and software-defined networking that increasingly support big data systems. Moreover, we provide a brief review of data centers topologies, routing protocols, and traffic characteristics, and emphasize the implications of big data on such cloud data centers and their supporting networks. Wide ranging efforts were devoted to optimize systems that handle big data in terms of various applications performance metrics and/or infrastructure energy efficiency. Finally, some insights and future research directions are provided.

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arXiv2019

Service Embedding in IoT Networks

The Internet of Things is anticipated to participate in the execution of a variety of complex tasks in the near future. IoT objects capable of handling multiple sensing and actuating functions are the cornerstone of smart applications such as smart buildings, smart factories, home automation, and healthcare automation. These smart applications express their demands in terms of high-level requests. These requests are characterised by the different requirements of sensing actuating functions, processing and memory needs, activation zones, latency, etc. In service-oriented architecture-based IoT, application requests are translated into a business process BP workflow. In this study, we model such a BP as a virtual network containing a set of virtual nodes and links connected in a specific topology. These virtual nodes represent the requested processing and location where sensing or actuation are needed. The virtual links capture the requested communication requirements between nodes. In this paper, we introduce a framework, optimised using mixed integer linear programming MILP, that embeds the BPs from the virtual layer into a lower-level implementation at the IoT physical layer. The proposed framework results in a physical plan that optimally allocates the processing needed and provisions the sensing and actuation at the required locations requirements to an appropriate set of IoT nodes. The optimisation goal is to minimise the IoT layer total power consumption and optimise the traffic distribution in a manner that minimises the traffic latency of each IoT node. Our results show that the proposed framework enhances the network performance by reducing the power consumption and latency.

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arXiv2019

Multi-branch Transmitter for Indoor Visible Light Communication Systems

One of the main aims of indoor visible light communication (VLC) systems is to deliver a high data rate service in single user and in multiuser scenarios. A key obstacle is the ability of the indoor VLC channel to support high data rates in the scenarios of interest. Here, we assess the potential of a multi-branch transmitter (MBT) and its use to achieve higher data rates in single user and multiuser indoor VLC systems. For the single user VLC system, the performance of the MBT is examined with a wide field of view (W-FOV) receiver and an angle diversity receiver (ADR) while for the multiuser VLC system we evaluate the performance of the MBT with a non-imaging angle diversity receiver (NI-ADR). In addition, for the multiuser VLC system, we propose subcarrier multiplexing (SCM) tones to allocate an optimum transmitter to each user. Furthermore, wavelength division multiplexing (WDM) is examined to support higher data rates for each user while using on-off-keying (OOK) modulation. In addition, the impact of the user's mobility on the multi-user VLC system performance is studied. The effect of diffuse reflections, mobility and lighting constraints are taken into account. In addition, the effect of co-channel interference (CCI) is considered in the multiuser VLC system.

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arXiv2019

Networking and processing in optical wireless

Optical wireless communication (OWC) is a promising technology that can provide high data rates while supporting multiple users. The Optical Wireless (OW) physical layer has been researched extensively, however less work was devoted to multiple access and how the OW front end is connected to the network. In this paper, an OWC system which employs a wavelength division multiple access (WDMA) scheme is studied, for the purpose of supporting multiple users. In addition, a cloud/fog architecture is proposed for the first time for OWC to provide processing capabilities. The cloud/fog-integrated architecture uses visible indoor light to create high data rate connections with potential mobile nodes. These optical wireless nodes are further clustered and used as fog mini servers to provide processing services through the optical wireless channel for other users. Additional fog processing units are located in the room, the building, the campus and at the metro level. Further processing capabilities are provided by remote cloud sites. A mixed-integer linear programming (MILP) model was developed and utilised to optimise resource allocation in the indoor OWC system. A second MILP model was developed to optimise the placement of processing tasks in the different fog and cloud nodes available. The optimisation of tasks placement in the cloud-/fog-integrated architecture was analysed using the MILP models. Multiple scenarios were considered where the mobile node locations were varied in the room and the amount of processing and data rate requested by each optical wireless node is varied. The results help identify the optimum colour and access point to use for communication for a given mobile node location and OWC system configuration, the optimum location to place processing and the impact of the network architecture. Areas for future work are identified.

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arXiv2019

Energy Efficient Resource Allocation in Vehicular Cloud based Architecture

The increasing availability of on-board processing units in vehicles has led to a new promising mobile edge computing (MEC) concept which integrates desirable features of clouds and VANETs under the concept of vehicular clouds (VC). In this paper we propose an architecture that integrates VC with metro fog nodes and the central cloud to ensure service continuity. We tackle the problem of energy efficient resource allocation in this architecture by developing a Mixed Integer Linear Programming (MILP) model to minimize power consumption by optimizing the assignment of different tasks to the available resources in this architecture. We study service provisioning considering different assignment strategies under varying application demands and analyze the impact of these strategies on the utilization of the VC resources and therefore, the overall power consumption. The results show that traffic demands have a higher impact on the power consumption, compared to the impact of the processing demands. Integrating metro fog nodes and vehicle edge nodes in the cloud-based architecture can save power, with an average power saving up to 54%. The power savings can increase by 12% by distributing the task assignment among multiple vehicles in the VC level, compared to assigning the whole task to a single processing node.

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arXiv2019

LiDAL: Light Detection and Localization

In this paper, we present the first indoor light-based detection and localization system that builds on concepts from radio detection and ranging (radar) making use of the expected growth in the use and adoption of visible light communication (VLC), which can provide the infrastructure for our LiDAL system. Our system enables active detection, counting and localization of people, in addition to being fully compatible with existing VLC systems. In order to detect human (targets), LiDAL uses the visible light spectrum, it sends pulses using a VLC transmitter and analyses the reflected signal collected by a photodetector receiver. Although we examine the use of the visible spectrum here, LiDAL can be used in the infrared spectrum and other parts of the light spectrum. We introduce LiDAL with different transmitter-receiver configurations and optimum detectors considering the fluctuation of the received reflected signal from the target in the presence of Gaussian noise. We design an efficient multiple input multiple output (MIMO) LiDAL system with wide field of view (FOV) single photodetector receiver, and also design a multiple input single output (MISO) LiDAL system with an imaging receiver to eliminate the ambiguity in target detection and localization. We develop models for the human body and its reflections and consider the impact of the colour and texture of the cloth used as well as the impact of target mobility. A number of detection and localization methods are developed for our LiDAL system including cross correaltion, a background subtraction method and a neural network based method. These methods are considered to distinguish a mobile target from the ambient reflections due to background obstacles (furniture) in a realistic indoor environment.

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arXiv2019

Artificial Neural Network for LiDAL Systems

In this paper, we introduce an intelligent light detection and localization (LiDAL) system that uses artificial neural networks (ANN). The LiDAL systems of interest are MIMO LiDAL and MISO IMG LiDAL systems. A trained ANN with the LiDAL system of interest is used to distinguish a human (target) from the background obstacles (furniture) in a realistic indoor environment. In the LiDAL systems, the received reflected signals in the time domain have different patterns corresponding to the number of targets and their locations in an indoor environment. The indoor environment with background obstacles (furniture) appears as a set of patterns in the time domain when the transmitted optical signals are reflected from objects in LiDAL systems. Hence, a trained neural network that has the ability to classify and recognize the received signal patterns can distinguish the targets from the background obstacles in a realistic environment. The LiDAL systems with ANN are evaluated in a realistic indoor environment through computer simulation.

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arXiv2019

Energy Efficient Virtual Machine Services Placement in Cloud-Fog Architecture

The proliferation in data volume and processing requests calls for a new breed of on-demand computing. Fog computing is proposed to address the limitations of cloud computing by extending processing and storage resources to the edge of the network. Cloud and fog computing employ virtual machines (VMs) for efficient resource utilization. In order to optimize the virtual environment, VMs can be migrated or replicated over geo-distributed physical machines for load balancing and energy efficiency. In this work, we investigate the offloading of VM services from the cloud to the fog considering the British Telecom (BT) network topology. The analysis addresses the impact of different factors including the VM workload and the proximity of fog nodes to users considering the data rate of state-of-the-art applications. The result show that the optimum placement of VMs significantly decreases the total power consumption by up to 75% compared to a single cloud placement.

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arXiv2019

Optimized Resource Allocation in Multi-user WDM VLC Systems

In this paper, we address the optimization of wavelength resource allocation in multi-user WDM Visible Light Communication (VLC) systems. A Mixed Integer Linear Programming (MILP) model that maximizes the sum of Signal-to-Interference-plus-Noise-Ratio (SINR) for all users is utilized. The results show that optimizing the wavelength allocation in multi-user WDM VLC systems can reduce the impact of the interference and improve the system throughput in terms of the sum of data rates for up to 7 users.

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