A stable, distributed dynamic call admission control for mobile wireless networks with QoS guarantee: the single traffic case

Call admission control is one of the key elements in ensuring the QoS in mobile wireless networks supporting multimedia applications. The traditional trunk reservation policy and its numerous variants give preferential treatment to the handoff calls over new arrivals by reserving a number of radio channels exclusively for handoffs. Such schemes, however, can lead to potentially poor radio channel utilization, due to the static nature. Given that radio channel is the scarce resource in mobile wireless networks, this conflict has to be carefully resolved. This paper introduces a new distributed and dynamic call admission control mechanism (SDCA), whose objective is to maximize the radio channel utilization subject to a pre-determined threshold of the call dropping probability. The novelties of the proposed mechanism are that we have taken into account the effects of limited channel capacity and time dependence on the call dropping probability. New calls are spread evenly over a control period, which leads to more effective and stable control. In addition, our scheme takes into consideration the influences from nearest and next-nearest neighboring cells. Simulations show that our scheme steadily satisfies the hard constraint on call dropping probability while maintaining a high channel throughput when compared with previous proposals