This tutorial paper addresses the physical layer security concerns and resiliency of Orthogonal Frequency Division Multiplexing (OFDM) communications; the de facto air-interface of most modern wireless broadband standards including 3GPP Long Term Evolution (LTE) and WiMAX. The paper starts with a brief introduction to the OFDM waveform and then reviews the robustness of the existing OFDM…
Tags: INET
Ergodic Capacity of SIM-Based DF Relayed Optical Wireless Communication Systems
In this letter, we consider a dual-hop, subcarrier intensity modulation-based relayed optical wirelesscommunication system under the combined influence of atmospheric turbulence and pointing error impairments. The turbulence-induced fading is modeled by independent but not necessarily identically distributed Gamma-Gamma fading statistics with misalignment fading. The relaying protocol followed by the relay is decode and forward. We first,…
CA-SVM: Communication-Avoiding Support Vector Machines on Distributed Systems
We consider the problem of how to design and implement communication-efficient versions of parallel support vector machines, a widely used classifier in statistical machine learning, for distributed memory clusters and supercomputers. The main computational bottleneck is the training phase, in which a statistical model is built from an input data set. Prior to our study, the…
BaProbSDN: A probabilistic-based QoS routing mechanism for Software Defined Networks
Over the past decade there has been an exponential increase in the Internet traffic especially with the proliferation of cloud computing and other distributed data services. This explosion of data traffic with its dynamically changing traffic patterns and flows might result in degradation of the network performance. In this context, there is a need for an intelligent…
Bootstrapping Software Defined Network for flexible and dynamic control plane management
To improve reliability and performance of Software Defined Networking (SDN) architectures, a number of recent efforts have proposed a logically centralized but physically distributed controller design that overcomes the bottleneck introduced by a single physical controller. Despite these advances, two key problems still persist. First, the task of controlling the host network and the task of controlling the control-plane network remain tightly intertwined,…
Quality of service control and resource prioritization with Software Defined Networking
In this study, we aim to analyze how Software Defined Networking (SDN) can help to ensure a high-quality uninterrupted Voice over Internet Protocol (VoIP) service accompanied by video for prioritized users and entities in a network congested with background traffic. Guaranteeing a level of Quality of Service (QoS) and resource prioritization are key concepts for future networks (e.g, 5G, NGSON) and may be…
Scalable application-aware resource management in software defined networking
SDN architecture based on separation of control and data plane in network devices enables realization of network programmability and application-aware networking. In this paper, we point out that the information of how applications are using network resources is ignored in modern SDN solution and should be recorded in application-aware SDN. We stress the importance of mapping applications tonetwork resources and maintaining such mapping…
Network Coded Software Defined Networking: Design and Implementation
Software Defined Networking (SDN) and Network Coding (NC) are two key concepts in networkingthat have garnered much attention in recent years. On the one hand, SDN’s potential to virtualize services in the Internet allows a large flexibility not only for routing data, but also to manage buffering, scheduling, and processing over the network. On the other hand, NC has shown great potential…
Multi-failure restoration with minimal flow operations in software defined networks
We consider dynamic flow restoration in multi-failure scenarios in OpenFlow-based Software-DefinedNetworks (SDNs). Flexibility of network configuration in these networks makes it possible to dynamically restore flows in case of multilink failures. To re-route the failed flows, network devices such as switches carry out flow operations, i.e., add new flow-entries to the flow-tables. In disaster scenarios where thousands of flows must be restored in…
A Survey of Security in Software Defined Networks
The proposition of increased innovation in network applications and reduced cost for network operators has won over the networking world to the vision of Software-Defined Networking (SDN). With the excitement of holistic visibility across the network and the ability to program network devices, developers have rushed to present a range of new SDN-compliant hardware, software and services. However, amidst this frenzy of activity, one key element has only recently entered…