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In many recent studies on cognitive radio (CR) networks, the primary user activity is assumed to follow the Poisson traffic model with exponentially distributed interarrivals. The Poisson modeling may lead to cases where primary user activities are modeled as smooth and burst-free traffic. As a result, this may cause the cognitive radio users to miss some(More)
The growing problem of spectrum scarcity and the inefficient spectrum utilization in the licensed bands, are addressed by the emerging Cognitive Radio (CR) paradigm. It is seen that the choice of the spectrum bands, called as spectrum decision, must be organized carefully by considering the challenges in the spectrum availability over time, the short term(More)
In this work, we study the detection of Fast-Flux Service Networks (FFSNs) using DNS (Domain Name System) response packets. We have observed that current approaches do not employ a large combination of DNS features to feed into the proposed detection systems. The lack of features may lead to high false positive or false negative rates triggered by benign(More)
Spectrum decision is an important functionality of Cognitive Radio Networks that directly effects the overall network performance of secondary users. Usually spectrum decision algorithms work on a decision cycle and produces results for the transmission cycle that comes afterwards. This situation brings out a latency and can be avoided by the spectrum(More)
There are three types of calls in a wireless cellular network; handover calls which terminate in a different cell than it originated from, inner calls which terminate in the originated cell and total calls which include both handover and inner calls. In our study, using empirical data, we first show that the handover rate of a regular cell is not(More)
Many wireless networks, which are controlled by a fixed spectrum assignment policy, suffer from the irregular utilization of the assigned spectrum. Cognitive Radio (CR) networks are proposed to solve this problem with dynamic spectrum access techniques. CR networks are usually deployed in the IEEE 802.11 based wireless networks, which require an access(More)
Self similar behavior of the aggregate traffic is a well known issue in the networking area. In this paper, we first study the self similarity of the empirically aggregated VoIP traffic in a heterogeneous wireless network testbed environment and then model it using Fractional Gaussian Noise (fGn). The heterogeneity of the environment is provided by(More)
Neuro-fuzzy systems, have recently been applied to the problem of Call Admission Control (CAC) in ATM networks. Their advantage as opposed to classical schemes, based on the modeling of sources connected to the network, is their capability to learn the behavior of data sources through training process, and to predict the future behavior based on the(More)
Duty cycling is an effective method for prolonging network lifetime in WSNs. In recent studies, dynamic duty cycle schemes are adopted with the use of asynchronous MAC protocols. The opportunistic routing employing forwarder set is applicable for duty-cycled WSNs. Moreover, remaining energy of nodes could be taken into account as a restriction when(More)