Alexandros G. Fragkiadakis

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—Cognitive radio (CR) has emerged as a promising technology to exploit the unused portions of spectrum in an opportunistic manner. The fixed spectrum allocation of governmental agencies results in unused portions of spectrum, which are called " spectrum holes " or " white spaces ". CR technology overcomes this issue, allowing devices to sense the spectrum(More)
—With the rapid proliferation of new technologies and services in the wireless domain, spectrum scarcity has become a major concern. The allocation of the Industrial, Medical and Scientific (ISM) band has enabled the explosion of new technologies (e.g. Wi-Fi) due to its licence-exempt characteristic. The widespread adoption of Wi-Fi technology, combined(More)
The proliferation of wireless networks has been remarkable during the last decade. The license-free nature of the ISM band along with the rapid proliferation of the Wi-Fi-enabled devices, especially the smart phones, has substantially increased the demand for broadband wireless access. However, due to their open nature, wireless networks are susceptible to(More)
In this paper we present and evaluate anomaly-based intrusion detection algorithms for detecting physical layer jamming attacks in wireless networks, by seeking changes in the statistical characteristics of the signal-to-noise ratio (SNR). Two types of algorithms are investigated: simple threshold algorithms and algorithms based on the cumulative sum change(More)
—Wireless mesh networks (WMNs) have attracted much attention lately for providing efficiently wireless services with high quality of service (QoS). Metropolitan WMNs are a low-cost solution for providing broadband wireless internet access in large areas. One of the fundamental issues of wireless communications is interference. In WMNs the interference can(More)
Internet of Things Life-logging Security Smart environment GNUradio a b s t r a c t As the world becomes an interconnected network where objects and humans interact with each other, new challenges and threats appear in the ecosystem. In this interconnected world, smart objects have an important role in giving users the chance for life-logging in smart(More)
This paper describes an experimental platform, optimised for Active Network processing. The system is based on a PC running Linux and operating a s a router. The active applications are downloaded in a FPGA based PCI board. An embedded hardware module monitors and manages the active applications at run time. A stable and safe reconfigurable platform for the(More)
A new reconfigurable active router architecture is presented in this paper. It consists of a software part and a hardware part. The software part is a set of kernel-space and user-space modules running on linux-PC. An FPGA PCI-based board with a Virtex-1600E FPGA forms the hardware part. The integration of reconfigurable hardware into standard PC hardware(More)