Berk Canberk

Learn More
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)
The recent problems in wireless cellular networks such as network capacity and indoor coverage have been addressed by the OFDMA small cells deployments of the Next-Generation LTE Advanced cellular systems. In this new paradigm, the deployment of hybrid access small cells can be seen as an optimal solution since they serve both the registered indoor users(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)
Two-tier femtocell-based networks have been proposed as an economic solution to improve coverage and capacity in wireless cellular systems. Although widely studied in the literature, interference management in these networks remains as a technical challenge in need of effective solutions. In particular, the interference estimation is a relevant portion of(More)
The tremendous increase in the mobile traffic requirements and the growing demands of large scale Cloud data centers have lead the network administrators to seek new management approaches. The Software Defined Networks (SDN) has raised as a promising solution providing more effective, programmable and granular configurations in order to isolate all the(More)
The tremendous increase in the mobile data traffic has led the network operators to use offloading solutions in Radio Access Technologies (RATs) such as WiFi or smallcells. However, these solutions are not efficient since none of them controls the offloading from a centralized global network view. Current offloading methods are mostly user-based and they do(More)