Abstract
To provide an efficient Call Admission Control (CAC) is one of the most important goals to be pursued if an efficient allocation of network resources to roaming and new users has to be addressed. Hierarchical network architectures are a common choice to build Broadband Wireless Access (BWA) networks able to provide added value services with different QoS levels. In a scenario where mobile hosts access the network via a wireless channel and are gated to the Internet through a hierarchical structure, this work aims to evidence the importance of an accurate design of the hierarchical network topology to obtain an efficient CAC process.