| The number of users is increasing quickly in mobile communication systems, and traffic types become diverse and quality of service (QoS) requirement needs to be greatly enhanced in recent years. So how to efficiently manage and use radio resource is one of the most important problems for network operators. How to support different QoS requirements of various services and utilize the valuable radio resource efficiently in the time-varying and interference-filled communication environment is now challenging in both3rd-generation mobile communication systems and future personal communication systems. Recently, as the most important part of radio resource management, call admission control (CAC) gets more attention.3GPP categorize traffic into four classes, including conversational, streaming, interactive, and background, while three of them are variable bit rate (VBR) except for conversation class. For the CDMA cellular communication system which carries different traffics, the research on system capacity is an important issue. An efficient analysis method is helpful to explore the factors affecting the system capacity and thus solutions can be found to optimize the utilization of radio spectrum. This thesis firstly proposes a QoS Negotiation-Based CAC algorithm, QoS parameters are negotiated during the admission procedure at heavy loaded cells, meanwhile maximum capacity, lower blocking rate and lower dropping rate are achieved. Then, this thesis introduces a price module to reduce network congestion through price adjustment. This thesis proposes a concept of the best arrival rate, which can both improve the effectiveness of the whole system through easing congestion and increase operators’income. |
