Opportunistic channel selection MAC protocol for cognitive radio ad hoc sensor networks in the internet of things

Internet of things (IoT) constitutes networked devices that can gather and exchange information. The scarcity of the available spectrum used by a large number of devices in IoT is a challenge. Spectrum scarcity changes the whole paradigm of spectrum access in order to increase utilization of the limited resource. Cognitive radio ad hoc sensor networks (CRASN) also operate on the same principle and exploit spectrum holes for efficient utilization of the spectrum. In a multi-channel CRASN, the dynamic nature of primary user (PU) activity and the resulting frequent channel switching require an efficient medium access control (MAC) protocol. A channel selection scheme cannot solely perform well without help of the MAC protocol. As a result, most of the channels remain underutilized, and eventually, overall system performance degrades. In this paper, an opportunistic MAC protocol for CRASN is proposed, and is compared to the IEEE 802.11 MAC protocol with round robin and random channel selection schemes. Furthermore, an opportunistic channel selection scheme (OCSS) is proposed. The simulation results confirm the effectiveness of the proposed approach in comparison of the round robin and random channel selection schemes.