  To fully empower sensor networks with cognitive Internet of Things (IoT)
technology, efficient medium access control protocols that enable the
coexistence of cognitive sensor networks with current wireless infrastructure
are as essential as the cognitive power in data fusion and processing due to
shared wireless spectrum. Cognitive radio (CR) is introduced to increase
spectrum efficiency and support such an endeavor, which thereby becomes a
promising building block toward facilitating cognitive IoT. In this paper,
primary users (PUs) refer to devices in existing wireless infrastructure, and
secondary users (SUs) refer to cognitive sensors. For interference control
between PUs and SUs, SUs adopt dynamic spectrum access and power adjustment to
ensure sufficient operation of PUs, which inevitably leads to increasing
latency and poses new challenges on the reliability of IoT communications.
  To guarantee operations of primary systems while simultaneously optimizing
system performance in cognitive radio ad hoc networks (CRAHNs), this paper
proposes interference-aware flooding schemes exploiting global timeout and
vaccine recovery schemes to control the heavy buffer occupancy induced by
packet replications. The information delivery dynamics of SUs under the
proposed interference-aware recovery-assisted flooding schemes is analyzed via
epidemic models and stochastic geometry from a macroscopic view of the entire
system. The simulation results show that our model can efficiently capture the
complicated data delivery dynamics in CRAHNs in terms of end-to-end
transmission reliability and buffer occupancy. This paper sheds new light on
analysis of recovery-assisted flooding schemes in CRAHNs and provides
performance evaluation of cognitive IoT services built upon CRAHNs.

Networking and Internet Architecture