Technical Articles

Cognitive radios with their ability to dynamically access unused portions of the radio spectrum have generated a lot of interest recently. In this paper we demonstrate an experimental cognitive radio network using Universal Software Radio Peripherals (USRPs). We have constructed a fully functional cognitive radio network with the ability to incorporate many of the requirements of a dynamic spectrum access system like the Wireless Regional Area Network (WRAN). The function of spectrum sensing is studied in detail. Along with the commonly used energy detector, two wideband sensing algorithms are implemented and a collaborative sensing scheme is also presented. A simple protocol is constructed which proves to be quite effective for the cognitive radios to dynamically change their transmitter and receiver parameters accordingly. Although the focus is on spectrum sensing, the whole system is scalable to conduct extensive research in all areas of cognitive radio.

Energy is becoming a very scarce resource. Hence, a shift towards a Green paradigm is increasingly dominating all kinds of industries nowadays. Energy saving is not the only goal of the green paradigm. Reducing pollution and waste emissions, especially CO2, is among the foreseen targets. A high percentage of research efforts, in all areas of industries, is devoted to reducing the CO2 footprint. Although ICT contributes to the CO2 emission only with a low percentage, ICT is not much different.  Many research efforts have been devoted to decrease the CO2 footprint of ICT. C2POWER, an EU funded project which aims at decreasing power consumption within mobile terminals in a multi-standard wireless environment, is one of those research efforts.

Network evolution towards self-aware autonomous adaptive networking aims at reducing the burden of configuring and managing networks, which leads to performance degradation. In order to optimize network operations, the introduction of self-awareness, self-management, and self-healing into the network was proposed, leading to a novel paradigm in networking — known as cognitive networking. However, such paradigm requires novel architectures to enable cooperation among network devices and across the network.

Homenetworks comprise very heterogeneous devices interconnected through a residential gateway (RGW). They interact in a cooperative way to provide the final user with advanced functionality. A characteristic example for this kind of cooperative systems is a multimedia network.