Cognitive radio networks (CRNs) are an emerging paradigm for next generation wireless
communication systems allowing for more ef cient radio spectrum utilization. In order to harness the full
potential that CRNs may offer, many challenges and problems need to be overcome and addressed. One of the
critical questions is the performance of secondary networks under primary user activity constraints. In this
respect, queueing assumes a primary role in characterizing the delay, throughput and other performance
metrics for secondary users, which in turn has implications for resource allocation, medium access control
and quality of service provisioning. This survey presents an overview and classi cation of the various
queueing models and techniques which have been proposed in the literature in the context of CRNs.
Furthermore, open problems, future research directions and further potential applications related to queueing
for CRNs are identi ed.