Join call admission control algorithm to enhance connection-level QoS in heterogeneous cellular networks

Next generation wireless networks will be heterogeneous where different radio access technologies (RATs) coexist. This coexistence of different RATs necessitates joint radio resource management. This paper proposes a joint call admission control (JCAC) algorithm for heterogeneous cellular networks and develop an analytical model for the JCAC. The cellular networks are integrated together and radio resources are jointly managed to support multiple classes of service. We decompose the integrated cellular networks into groups of co-located cells. In each group of co-located cells, the objectives of the JCAC algorithm are to uniformly distribute traffic load among the available RATs, prioritized handoff calls over new calls, and enhance connection-level QoS. Prioritization of handoff calls over new calls is achieved by using threshold-based bandwidth reservation method. The JCAC algorithm is modeled as a multidimensional Markov chain. We derive two connection-level QoS metrics, new call blocking probability and handoff call dropping probability, for the heterogeneous cellular network and then evaluate the performance of the JCAC algorithm through simulations. Results show that connection-level QoS can be significantly increased by using the JCAC algorithm in heterogeneous cellular networks.