There has been tangible growth in the investigation of cognitive radio (CR) communication and networking over the past few years. Sharing and digital switchover (DSO) TV band technology and issuing regularities concerned with its utilization as the host of secondary users have created a riverbed for the practical stream of ideas related to CR. On the other hand, the heavy burden of numerous users in machine type communications (MTC) and Internet of Things (IoT) is envisioned in the near future, and the role of CR technology to handle and mitigate the issue of certain increasing spectrum demand in wireless communications cannot be ignored.

Defining a scenario that would be able to reflect all the complexities of relationships among the entities in CR communication and networking is a difficult task. The introduction features descriptions of constrained IoT network initiation and communication mechanisms (internal and external). The evolution and routing mechanisms in CR are thoroughly referenced in the literature review section. It reviews the roles of common control channel (CCC), directional routing protocols and route propagation mechanisms in CR networking.

The connecting routes among the cognitive nodes via the primary user’s channel are modeled via matriciadal notations, which indicate the topology of the nodes in the network with their directionality and vacancy situation to model a destination-oriented directed acyclic graph (DODAG).

The drawbacks of traditional CCC-based CR ad hoc on-demand distance vector (AODV) routing include non-optimized energy consumption, cognitive control channel saturation, and directional multichannel hidden terminals. The proposed hybrid-CCC-CR-AODV protocol uses node-channel and node-direction matrices. The paper includes a diagram to express the mechanism of end-to-end datagram transmission and control at hybrid CCC (902MHz + TV whitespace (TVWS) (420MHz)).

The paper also discusses synchronization, channel discovery, and directional antennas at end-to-end transmission. Experimental samples in the simulation results, which include average end-to-end throughput, packet delay, and energy consumption, indicate the supremacy of the proposed method compared with traditional methods.

Despite the nicely presented introduction, literature review, and modeling sections, which reflect the authors’ knowledge of the topic, the paper does not develop their proposal in an algorithmic and analytic way. Thus, it should be considered a marginal contribution to the field.