Cognitive radios have been identified as a solution to the crowded spectrum issue. With the realization of cognitive radio networks came the recognition that both new and old security threats are relevant. The cognitive radio network is still vulnerable to many of the denial of service, wormhole, routing, and jamming attacks that plague other wireless technologies. In addition, the cognitive ra...

A cognitive radio wireless sensor network is one of the candidate areas where cognitive techniques can be used for opportunistic spectrum access. Research in this area is still in its infancy, but it is progressing rapidly. The aim of this study is to classify the existing literature of this fast emerging application area of cognitive radio wireless sensor networks, highlight the key research t...

Spectrum scarcity and underutilization in wireless networks, arising due to traditional static spectrum allocation, have been of great concern since the past decade. The suboptimal use of spectrum motivates new wireless concepts where unlicensed users opportunistically access licensed spectrum using cognitive radio technology. A cognitive radio can change its operating parameter intelligently i...

Cognitive radio is one of the most promising wireless technologies and has been recognized as a new way to improve the spectral efficiency of wireless networks. In a cognitive radio network, secondary users exchange control information for network coordination such as transmitter-receiver handshakes, for sharing spectrum sensing results, for neighbor discovery, to maintain connectivity, and so ...

In this paper we apply the concept of overlay cognitive radio to the communication between nodes in a wireless mesh network. Based on the overlay cognitive radio model, it is possible to have two concurrent transmissions in a given interference region, where usually only one communication takes place at a given time. We analyze the cases of wireless mesh networks with regular and random topolog...

The emerging HetNet is asking for new network deployment and management methods with flexibility to handle dynamic user demands and diverse radio environments in a tired RAN infrastructure. In this Brief, we present a new framework in the study of HetNet, namely as cognitive cellular network management (CCN), by applying cognitive radio techniques. As shown in Fig. 2.1, CCN are built upon four ...

In this paper, we introduce a joint flow control and scheduling algorithm for multi-hop cognitive radio networks with spectrum underlay. Our proposed algorithm maximizes the total utility of secondary users while stabilizing the cognitive radio network and still satisfies the total interference from secondary users to primary network is less than an accepted level. Based on Lyapunov optimizatio...

As many kind of spectrum sensing techniques have been introduced for various wireless technologies. These spectrum sensing models have been improved the spectrum usage and have also opened up new opportunities for the different wireless applications to utilize the radio spectrum more effectively. To exploit these opportunities, the wireless transceivers need to be more intelligent to access the...

The emerging HetNet is asking for new network deployment and management methods with flexibility to handle dynamic user demands and diverse radio environments in a tired RAN infrastructure. In this Brief, we present a new framework in the study of HetNet, namely as cognitive cellular network management (CCN), by applying cognitive radio techniques. As shown in Fig. 2.1, CCN are built upon four ...

Cognitive Radio (CR) is a promising technique to address the spectrum scarcity issue by enabling the unlicensed network users (SUs) to dynamic access the spectrum holes. This thesis designs Medium Access Control (MAC) protocols for SUs to utilize the unused spectrum without interfering the licensed network users’ (PUs) transmissions; analyzes the MAC performance based on the queuing theories; a...