A New CAC Policy Based on Traffic Characterization in Cellular Networks

Abstract

Abstract. The Call Admission Control (CAC) method presented in this paper is based on the statistical properties of the network's traffic variables. It probabilistically estimates the time until the release of a seized channel: the admission control depends on the computed mean remaining time averaged along all channels at a specific instant and on a time threshold. The policy produces a smooth transition between the QoS metrics, giving the operator the freedom to design the network at the desired QoS point. Another valuable property is that the algorithm is straightforward and fed only by simple teletraffic metrics: distribution and the first and second moments of Channel Holding Time (CHT). Simplicity is important for a CAC method because decisions for accepting or rejecting calls must be computed quickly and frequently.

Performance of a Traffic-Based Handover Method in High-Mobility Scenarios

“…The handover method in [7] is based on the real statistical behaviour of the traffic variables, in contrast to the common approach in which exponential assumptions are made. Analytical studies [8,9] and empirical measurements [10] that examine the nature of the processes that take place in mobile networks show that the negative exponential distribution (n.e.d.)…”

“…As explained in [7] and the references therein, this value can be analytically estimated according to the following expression:…”

“…The r.v. used is called mean remaining time (MRT) and is averaged along all of the C channels in the system [7] as follows:…”

“…The goal of this study is to evaluate the performance of the method proposed in [7] in environments with high mobility and large handover (i.e. overlapping) areas.…”

“…The method proposed in [7] uses estimates of the traffic profile and considers the current state of the network. It provides smooth control of the PB of new calls and the PF of handover calls.…”