Performance analysis of hierarchical cellular systems with multiple class traffic

Abstract

Hierarchical Cell Structure(HCS) describes a system where at least two types of cells (e.g., macrocell and microcell) operate one upon an-other. As the mobile teletraffic demands increase dramatically and the wireless multimedia services of IMT-2000 systems are required, interest in the cellular system with the hierarchical structure has emerged. Specially, a microcell hot spot embedded in CDMA macrocell systems can provide a high capacity in the service areas with a higher teletrafc density or areas that are poorly covered. The studies of HCS had been extensively carried on for various environments. However, most of the studies were based on only single traffic such as voice service. For wireless multimedia services of IMT-2000 systems, we must concern about the mixed traffic environment where there are two or more types of class in each cell. And, in order to manage optimal radio resource, call admission control is considered for multiple types of services requir-ing different SIRs(Signal to Interference Ratio) and transmission rates in a CDMA overlaid/underlaid macrocell and microcell structure. Call admission control can significantly impact the performance of a cellular system. In this thesis, we show how call admission can be used to optimize the performance of a hierarchical cellular system. Performance measures such as blocking probability of new call and throughput with the optimal power allocation are obtained by computer simulation.