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—Most existing studies of spectrum usage have been performed by actively sensing the energy levels in specific RF bands including cellular bands. In this paper, we provide a unique, complementary analysis of cellular primary usage by analyzing a dataset collected inside a cellular network operator. One of the key aspects of our dataset is its scale – it(More)
Dynamic Spectrum Access (DSA) approaches, which propose to opportunistically use underutilized portions of licensed wireless spectrum such as cellular bands, are increasingly being seen as a way to alleviate spectrum scarcity. However, before DSA approaches can be enabled, it is important that we understand the dynamics of spectrum usage in licensed bands.(More)
Simulating the physical layer of wireless communication remains a challenge. Communication standards like OFDM or MIMO systems go beyond the simple single narrow frequency band, single antenna model used in popular simulators. Yet, these technologies gain popularity, since they provide researchers with a plethora of possibilities that can be explored to(More)
Energy Framework is an extensible OMNeT++ framework for modeling battery consumption in wireless networks. It is designed so there is a clear separation between model-ing of battery state and energy consuming operations, enabling more sophisticated modeling of system behavior. The Energy Framework is largely implemented in " pure " OM-NeT++; it has been(More)
—The fundamental condition for the legal approval of Dynamic Spectrum Access (DSA) approaches is the protection of the Primary User (PU). However, for DSA to become an attractive service reality, it is crucial to ensure also some Quality of Service (QoS) support for the Secondary User (SU) communication. In this paper, we discuss sensing based opportunistic(More)
The sub-optimal exploitation of radio spectrum is widely accepted. Cognitive radio is a technology that aims to address this issue and improve the overall efficiency of radio spectrum utilization. However, this promising technology is far from being mature at present. In addition to theoretical research, experimentally-driven research is needed to convince(More)
—One of the major challenges in designing cellular Cognitive Radio (CR) networks is the avoidance of Secondary User (SU) interference to so called Primary Users (PUs) operating in the licensed bands. Usually, SU operation has to be interrupted periodically in order to detect PU activity and avoid the respective frequencies. Recently, Dynamic Frequency(More)
—IEEE 802.11 WLANs are currently one of the most popular wireless technologies, but their immediate success results in dense deployments and high demand of user traffic. This in turn leads to decrease in throughput and poor spectrum utilization. Especially in the 2.4 GHz ISM band, where the spectrum is a very scarce resource, all available WLAN channels(More)
Sensing mechanisms that estimate the occupancy of wireless spectrum are crucial to the success of approaches based on Dynamic Spectrum Access. In this paper, we present key insights into this problem by empirically investigating the design of sensing mechanisms applied to check the availability of excess capacity in CDMA voice networks. We focus on(More)