Cloud computing is a revolutionary process that has impacted the manner of using networks. It all... more Cloud computing is a revolutionary process that has impacted the manner of using networks. It allows a high level of flexibility as Virtual Machines (VMs) run elastically workloads on physical machines in data centers. The issue of placing virtual machines (VMP) in cloud environments is an important challenge that has been thoroughly addressed, although not yet completely resolved. This article discusses the different problems that may disrupt the placement of VMs and Virtual Network Functions (VNFs), and classifies the existing solutions into five major objective functions based on multiple performance metrics such as energy consumption, Quality of Service, Service Level Agreement, and incurred cost. The existing solutions are also classified based on whether they adopt heuristic, deterministic, meta-heuristic or approximation algorithms. The VNF placement in 5G network is also discussed to highlight the convergence toward optimal usage of mobile services by including NFV/Software-...
Video streaming has often suffered from a quality of experience (QoE) degradation related to play... more Video streaming has often suffered from a quality of experience (QoE) degradation related to playback interruptions and buffering events. Therefore, the video file should be prefetched before starting playback. This paper aims to optimize the QoE of video streaming by exploiting the trade-off between starvation probability and start-up delay. First, we analyze the starvation probability of different file distributions (i.e. Exponential distribution, Pareto distribution, Log-normal distribution and Uniform distribution). Second, we adopt Lagrange multiplier to identify the optimal start-up delay to prevent the repeated starvation events during the video playout. The simulation results show that the proposed approach reduces the startup-delay by 40%.
Using millimeter wave (mmWave) bands in 5G self-organizing networks has a significant potential t... more Using millimeter wave (mmWave) bands in 5G self-organizing networks has a significant potential to provide high bandwidth. However, the major challenge lies in initial access beamforming where mmWave communications suffer from deafness problem that may cause a significant loss in the received power especially when narrow beams are adopted. This paper tackles the problem of beam alignment in mmWave 5G. The problem is formulated as a non-cooperative game between transmitter and receiver where each player tries to align its beamforming direction in a way to obtain maximum throughput. We first provide a full characterization of pure Nash equilibria. Then, we propose a gradient descent algorithm that allows users to learn their optimal beamwidth. Simulation results prove the performance of our beam alignment model since mmWave frequencies deliver narrow beams with high gain and significant capacity.
2020 IEEE Canadian Conference on Electrical and Computer Engineering (CCECE), 2020
With the emergence of network function virtualization (NFV) and Software-Defined Networking (SDN)... more With the emergence of network function virtualization (NFV) and Software-Defined Networking (SDN) technologies, virtual network functions (VNF) can be interconnected to deliver different mobile services in 5G communication networks. Our primary purpose is to find the optimal VNF placement reducing resource consumption while providing specific latency and throughput for slicing services. We consider VNFs as M/M/1/C queues chained together to serve customer requests. The problem relies on finding an efficient orchestration and placement of VNFs. In this context, we propose a decision algorithm based two-procedures, the first one, named orchestration phase, aims to manage the reuse of VNFs having the same required functions through a dynamic logit method, and the second one is related to the new placement of VNFs. In this paper, we focus on a simple scenario of delivering video streaming service traversing a standard chain of four VNFs. Simulation results prove the performance of our proposed algorithm in terms of End-to-End delay and dropping probability compared to greedy and affinity algorithms.
Cloud computing is a revolutionary process that has impacted the manner of using networks. It all... more Cloud computing is a revolutionary process that has impacted the manner of using networks. It allows a high level of flexibility as Virtual Machines (VMs) run elastically workloads on physical machines in data centers. The issue of placing virtual machines (VMP) in cloud environments is an important challenge that has been thoroughly addressed, although not yet completely resolved. This article discusses the different problems that may disrupt the placement of VMs and Virtual Network Functions (VNFs), and classifies the existing solutions into five major objective functions based on multiple performance metrics such as energy consumption, Quality of Service, Service Level Agreement, and incurred cost. The existing solutions are also classified based on whether they adopt heuristic, deterministic, meta-heuristic or approximation algorithms. The VNF placement in 5G network is also discussed to highlight the convergence toward optimal usage of mobile services by including NFV/Software-...
Video streaming has often suffered from a quality of experience (QoE) degradation related to play... more Video streaming has often suffered from a quality of experience (QoE) degradation related to playback interruptions and buffering events. Therefore, the video file should be prefetched before starting playback. This paper aims to optimize the QoE of video streaming by exploiting the trade-off between starvation probability and start-up delay. First, we analyze the starvation probability of different file distributions (i.e. Exponential distribution, Pareto distribution, Log-normal distribution and Uniform distribution). Second, we adopt Lagrange multiplier to identify the optimal start-up delay to prevent the repeated starvation events during the video playout. The simulation results show that the proposed approach reduces the startup-delay by 40%.
Using millimeter wave (mmWave) bands in 5G self-organizing networks has a significant potential t... more Using millimeter wave (mmWave) bands in 5G self-organizing networks has a significant potential to provide high bandwidth. However, the major challenge lies in initial access beamforming where mmWave communications suffer from deafness problem that may cause a significant loss in the received power especially when narrow beams are adopted. This paper tackles the problem of beam alignment in mmWave 5G. The problem is formulated as a non-cooperative game between transmitter and receiver where each player tries to align its beamforming direction in a way to obtain maximum throughput. We first provide a full characterization of pure Nash equilibria. Then, we propose a gradient descent algorithm that allows users to learn their optimal beamwidth. Simulation results prove the performance of our beam alignment model since mmWave frequencies deliver narrow beams with high gain and significant capacity.
2020 IEEE Canadian Conference on Electrical and Computer Engineering (CCECE), 2020
With the emergence of network function virtualization (NFV) and Software-Defined Networking (SDN)... more With the emergence of network function virtualization (NFV) and Software-Defined Networking (SDN) technologies, virtual network functions (VNF) can be interconnected to deliver different mobile services in 5G communication networks. Our primary purpose is to find the optimal VNF placement reducing resource consumption while providing specific latency and throughput for slicing services. We consider VNFs as M/M/1/C queues chained together to serve customer requests. The problem relies on finding an efficient orchestration and placement of VNFs. In this context, we propose a decision algorithm based two-procedures, the first one, named orchestration phase, aims to manage the reuse of VNFs having the same required functions through a dynamic logit method, and the second one is related to the new placement of VNFs. In this paper, we focus on a simple scenario of delivering video streaming service traversing a standard chain of four VNFs. Simulation results prove the performance of our proposed algorithm in terms of End-to-End delay and dropping probability compared to greedy and affinity algorithms.
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Papers by wissal Attaoui