Flexible call admission control schemes for DS-CDMA systems with non-uniform traffics

In a DS-CDMA system, due to the inter-cell interference, the resources of a cell are occupied not only by the users in the home cell but also by the users in neighboring cells. When the traffic load is high in a DS-CDMA system, allowing a local user to occupy resources sometimes blocks several call requests in the neighboring cells. In this paper, flexible CAC schemes are proposed as a solution to the above problem and compared with conventional CAC scheme under uniform and non-uniform traffic distributions. Flexible CAC schemes reserve small part of resources for call requests in other cells instead of accepting a call request in its own cell. Reserving small part reduces the overall average blocking rate when the traffic load is high. Especially when the traffics are non-uniform. A flexible CAC scheme outperforms a conventional CAC scheme.