Interference Power Based Uplink Admission Control in Enhanced WCDMA

WCDMA systems equipped with enhanced uplink (EUL) are currently being rolled out. When using EUL, rapid scheduling in the base stations makes it possible to operate at an interference power level above a reasonable admission limit for dedicated data channels. Thus, an admission control hosted in a central node that considers the total interference power may reject users due best effort traffic on EUL. As a remedy to this, a new measurement representing the interference power from scheduled transmission has been incorporated in the 3GPP specification. This contribution shows that it is possible to recover most of the accessibility, i.e., users' probability of accessing the system, lost when introducing EUL if the new measurement is used appropriately. To this end, two admission control algorithms are proposed and compared in system simulations. The algorithms consider the total interference power and the interference power due to non-scheduled traffic, respectively.