Lower and Upper Bounds for Throughput Capacity of a Cognitive Ad Hoc Network Overlaid on a Cellular Network

In this paper, we compute lower and upper bounds for the throughput capacity of an ad hoc network overlaid on a cellular network. The ad hoc network is comprised of a specific number of wireless cognitive nodes that opportunistically exploit the inactive frequency channels in the cellular network. In this respect, we employ a model recently proposed for single-channel mobile ad-hoc network after some minor modifications. The proposed framework consists of two queueing networks, a closed BCMP queueing network comprised of M/G/co nodes capable of mobility modeling, and an open BCMP queueing network comprised of symmetric M/G/l nodes capable of modeling the packet transmission process. By including the results of the first queueing network and mapping MAC and routing schemes as well as the opportunistic behavior of cognitive nodes onto suitable components of second queueing network we are able to find lower and upper bounds for throughput capacity. We apply our approach in several conditions and confirm our analytical results by simulation.