1,629 research outputs found

    A baseband wireless spectrum hypervisor for multiplexing concurrent OFDM signals

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    The next generation of wireless and mobile networks will have to handle a significant increase in traffic load compared to the current ones. This situation calls for novel ways to increase the spectral efficiency. Therefore, in this paper, we propose a wireless spectrum hypervisor architecture that abstracts a radio frequency (RF) front-end into a configurable number of virtual RF front ends. The proposed architecture has the ability to enable flexible spectrum access in existing wireless and mobile networks, which is a challenging task due to the limited spectrum programmability, i.e., the capability a system has to change the spectral properties of a given signal to fit an arbitrary frequency allocation. The proposed architecture is a non-intrusive and highly optimized wireless hypervisor that multiplexes the signals of several different and concurrent multi-carrier-based radio access technologies with numerologies that are multiple integers of one another, which are also referred in our work as radio access technologies with correlated numerology. For example, the proposed architecture can multiplex the signals of several Wi-Fi access points, several LTE base stations, several WiMAX base stations, etc. As it able to multiplex the signals of radio access technologies with correlated numerology, it can, for instance, multiplex the signals of LTE, 5G-NR and NB-IoT base stations. It abstracts a radio frequency front-end into a configurable number of virtual RF front ends, making it possible for such different technologies to share the same RF front-end and consequently reduce the costs and increasing the spectral efficiency by employing densification, once several networks share the same infrastructure or by dynamically accessing free chunks of spectrum. Therefore, the main goal of the proposed approach is to improve spectral efficiency by efficiently using vacant gaps in congested spectrum bandwidths or adopting network densification through infrastructure sharing. We demonstrate mathematically how our proposed approach works and present several simulation results proving its functionality and efficiency. Additionally, we designed and implemented an open-source and free proof of concept prototype of the proposed architecture, which can be used by researchers and developers to run experiments or extend the concept to other applications. We present several experimental results used to validate the proposed prototype. We demonstrate that the prototype can easily handle up to 12 concurrent physical layers

    Can open-source projects (re-) shape the SDN/NFV-driven telecommunication market?

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    Telecom network operators face rapidly changing business needs. Due to their dependence on long product cycles they lack the ability to quickly respond to changing user demands. To spur innovation and stay competitive, network operators are investigating technological solutions with a proven track record in other application domains such as open source software projects. Open source software enables parties to learn, use, or contribute to technology from which they were previously excluded. OSS has reshaped many application areas including the landscape of operating systems and consumer software. The paradigmshift in telecommunication systems towards Software-Defined Networking introduces possibilities to benefit from open source projects. Implementing the control part of networks in software enables speedier adaption and innovation, and less dependencies on legacy protocols or algorithms hard-coded in the control part of network devices. The recently proposed concept of Network Function Virtualization pushes the softwarization of telecommunication functionalities even further down to the data plane. Within the NFV paradigm, functionality which was previously reserved for dedicated hardware implementations can now be implemented in software and deployed on generic Commercial Off-The Shelf (COTS) hardware. This paper provides an overview of existing open source initiatives for SDN/NFV-based network architectures, involving infrastructure to orchestration-related functionality. It situates them in a business process context and identifies the pros and cons for the market in general, as well as for individual actors

    Continuous and Concurrent Network Connection for Hardware Virtualization

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    This project addresses the network connectivity in virtualization for cloud computing. Each Virtual Machine will be able to access the network concurrently and obtains continuous internet connectivity without any disruption. This project proposes a new method of resource sharing which is the Network Interface Card (NIC) among the Virtual Machines with each of them having the full access to it with near-native bandwidth. With this, could computing can perform resource allocation more effectively. This will be essential to migrate the each Operating System (Virtual Machine) that resides on one physical machine to another without disrupting its internet or network connection

    Security, Performance and Energy Trade-offs of Hardware-assisted Memory Protection Mechanisms

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    The deployment of large-scale distributed systems, e.g., publish-subscribe platforms, that operate over sensitive data using the infrastructure of public cloud providers, is nowadays heavily hindered by the surging lack of trust toward the cloud operators. Although purely software-based solutions exist to protect the confidentiality of data and the processing itself, such as homomorphic encryption schemes, their performance is far from being practical under real-world workloads. The performance trade-offs of two novel hardware-assisted memory protection mechanisms, namely AMD SEV and Intel SGX - currently available on the market to tackle this problem, are described in this practical experience. Specifically, we implement and evaluate a publish/subscribe use-case and evaluate the impact of the memory protection mechanisms and the resulting performance. This paper reports on the experience gained while building this system, in particular when having to cope with the technical limitations imposed by SEV and SGX. Several trade-offs that provide valuable insights in terms of latency, throughput, processing time and energy requirements are exhibited by means of micro- and macro-benchmarks.Comment: European Commission Project: LEGaTO - Low Energy Toolset for Heterogeneous Computing (EC-H2020-780681

    Cloud Computing cost and energy optimization through Federated Cloud SoS

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    2017 Fall.Includes bibliographical references.The two most significant differentiators amongst contemporary Cloud Computing service providers have increased green energy use and datacenter resource utilization. This work addresses these two issues from a system's architectural optimization viewpoint. The proposed approach herein, allows multiple cloud providers to utilize their individual computing resources in three ways by: (1) cutting the number of datacenters needed, (2) scheduling available datacenter grid energy via aggregators to reduce costs and power outages, and lastly by (3) utilizing, where appropriate, more renewable and carbon-free energy sources. Altogether our proposed approach creates an alternative paradigm for a Federated Cloud SoS approach. The proposed paradigm employs a novel control methodology that is tuned to obtain both financial and environmental advantages. It also supports dynamic expansion and contraction of computing capabilities for handling sudden variations in service demand as well as for maximizing usage of time varying green energy supplies. Herein we analyze the core SoS requirements, concept synthesis, and functional architecture with an eye on avoiding inadvertent cascading conditions. We suggest a physical architecture that diminishes unwanted outcomes while encouraging desirable results. Finally, in our approach, the constituent cloud services retain their independent ownership, objectives, funding, and sustainability means. This work analyzes the core SoS requirements, concept synthesis, and functional architecture. It suggests a physical structure that simulates the primary SoS emergent behavior to diminish unwanted outcomes while encouraging desirable results. The report will analyze optimal computing generation methods, optimal energy utilization for computing generation as well as a procedure for building optimal datacenters using a unique hardware computing system design based on the openCompute community as an illustrative collaboration platform. Finally, the research concludes with security features cloud federation requires to support to protect its constituents, its constituents tenants and itself from security risks

    CyberGuarder: a virtualization security assurance architecture for green cloud computing

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    Cloud Computing, Green Computing, Virtualization, Virtual Security Appliance, Security Isolation
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