LAUSR

The Internet of Things (IoT) is a novel network that transforms our future by interconnecting everything. With the rapid deployment of IoT devices and applications, a large amount of data is introduced into the network. Hence, we may suffer spectrum scarcity issue due to the massive data. Cognitive radio (CR) is a potential solution for addressing this issue, which can improve spectrum efficiency by dynamic spectrum access. The IoT device with CR capability has become a new research interest. In this article, we propose a full-duplex-based control channel establishment (FDCCE) scheme for cognitive IoT (CIoT). In the FDCCE scheme, CR-based IoT devices (CRDs) can establish control channels on both licensed spectrum and unlicensed spectrum without a central entity. By combining the licensed spectrum and the unlicensed spectrum, the control channel between CRDs can be established successfully even though there is no common available licensed channel between them. Moreover, CRDs with FD radios can sense and transmit data on the same channel simultaneously. Hence, the interference with licensed primary users can be effectively avoided while the time for dedicated spectrum sensing can be saved. Rendezvous on the same channel is the necessary process for the control channel establishment between CRDs. Performance analysis demonstrates the upper bound of the maximum time to rendezvous, channel loading, and degree of rendezvous for the FDCCE scheme. Simulation results show the superiority of the FDCCE scheme in terms of time to rendezvous.