Towards Security Issues and Solutions in Cognitive Radio Networks

1. Introduction

Nowadays, there is an unexpected explosion in the demand for wireless network resources. This is due to the intense increase in the number of the emerging services. For wireless computer network, limited bandwidth along with the transmission quality requirements for users, make quality of service (QoS) provisioning a very challenging problem as highlighted by Bhargavaand et al. (2007). To overcome spectrum scarcity problem, Federal Communications Commission (FCC) has already started working on the concept of spectrum sharing where unlicensed users (also known as secondary users or SUs) can share the spectrum with licensed users (also known as primary users or PUs), provided they respect PUs rights to use spectrum exclusively. The underutilization of the allocated spectrum has been also reported by the Spectrum Policy Task Force appointed by Federal Communications Commission (FCC) (2002).

In spectrum sharing based CR networks, secondary users (SUs) coexist with a primary user (licensed) system. A fundamental challenge is how to serve SUs while ensuring the quality of service (QoS) of the primary user (PU).

Cognitive radio networks (CRNs) are smart networks that automatically sense the channel and adjust the network parameters accordingly. In CRN, the unlicensed user (SU) has the possibility of using large amounts of unused spectrum in an efficient way while reducing interference with other licensed user (PU). The key technology in CRNs that enables the SUs to sense and utilize the spectrum is the radio technology. This technology is an emerging technology that enables the dynamic deployment of highly adaptive radios that are built upon software defined radio technology (SDR) as mentioned in Dhar et al. (2006) and Qusay et al. (2007). Moreover, it allows the unlicensed operation to be in the licensed band. We show the tasks in cognitive radio network that have been conducted from 2006 to 2014 in Table 1.