Call admission on the uplink of a CDMA system based on total received power

Abstract

We consider the problem of admitting calls to a CDMA wireless network supporting stream and packet services over a range of transmission rates and offering possibly different grades of service. Resource requirements are considered separately for the uplink and downlink. The high-level objective is to design a simple admission scheme for the uplink that ensures adequate signal-to-interference ratios for both the incoming call (if accepted), as well as previously admitted calls. Our approach is based on two key ideas: (a) a measure of resource utilization that is independent of how resources are allocated among the ongoing calls, and (b) an estimate of the additional resources required because of the new call seeking admission. The current work considers measurement of the received interference power distribution and estimation of its displacement as a result of admitting a new call. The interference distribution is obtained from the power control module. The interference displacement is estimated based on the characteristics of the incoming call and the current resource utilization. Dynamic call capacities are compared with static capacities to indicate the effectiveness of the algorithm in achieving high network utilization with low probability of overload.