Call admission control in multiservice high altitude platform (HAP) W-CDMA cellular systems

Of the various radio resource management functions, in this paper we focus on call admission control (CAC). We propose a CAC scheme for multiservice High Altitude Platform (HAP) wideband code division multiple access (W-CDMA) cellular systems that caters for multimedia services. HAPs have known increasing popularity during the past few years and are expected to play a pivotal role in the telecommunications arena by virtue of their appealing features. We first study the uplink capacity of a multiservice HAP W-CDMA cellular system taking into consideration power control imperfections and evaluate the degradation that a new call induces in the quality of service of ongoing calls. Based on the obtained statistics, we then develop a CAC scheme that takes account of power control imperfections and user mobility and compare it to a CAC scheme that is based on instantaneous energy per bit to noise power spectral density ratio (Eb/N0) measurements. Additionally, we examine these algorithms for two different criteria that apply to both new and handoff call requests. The first criterion is based on the minimum Eb/N0 of the first tier cells, while the second bases its decision upon the mean Eb/N0 of the cells of the first tier. Simulation studies further document and confirm the positive characteristics of the proposed CAC scheme.