Structured Admission Control Policy in Heterogeneous Wireless Networks with Mesh Underlay

In this paper, we investigate into optimal admission control policies for Heterogeneous Wireless Networks (HWN), considering an integration of wireless mesh networks with an overlaying cellular infrastructure. In order to characterize the overflow traffic from the underlaying mesh to the overlay, a Partially-Observable Markov-Modulated Poisson Process (PO-MMPP) traffic model is developed. This model captures the burstiness of the overflow traffic under the imperfect observability of the mesh network states. Then, by modeling the overlay network as a controlled PO-MMPP/M/C/C queueing system and obtaining structured decision theoretic results, it is shown that the optimal control policies for this class of HWNs can be characterized as monotonic threshold curves. Further, these results are used to design a computationally efficient algorithm to determine the optimal policy in terms of thresholds. Numerical observations suggest that the proposed algorithm is efficient in terms of time-complexity and can drastically reduce the cost of dropped and blocked calls.