An efficient soft admission control technique for wireless communications

In this paper, an innovative Admission Control (AC) policy for CDMA wireless networks, based on minimizing the Multiple-Access-Interference (MAI), is introduced. According to our proposal, an incoming connection is accepted whenever the QoS constraints, for all communications, are respected, that is, the Signal-to-Interference-plus-Noise-Ratio (SINR) is kept under control. This parameter mainly depends on traffic load variations. Thus, the MAI arising from a new connection must be considered. This problem can be proactively faced by characterizing MAI and correctly estimating its value. Furthermore, two approaches are presented, named, respectively, Static Soft AC and Dynamic Soft AC; the latter involving a dynamic power management. Analytical models describing the first approach are investigated and validated by means of simulations performed on a typical uplink UMTS environment. Moreover, a remarkable gain of the second approach, in terms of dropping probability, is highlighted without, thus rendering our approach a proper candidate for variable network traffic management.