الفهرس | Only 14 pages are availabe for public view |
Abstract The importance of study asynchronous transfer mode (ATM) networks is that ATM is considered as the appropriate transmission technology for both local and wide area broadband communication networks. The most important attraction of ATM is its support for a number of different types of applications and services with widely varying degrees of traffic characteristics and quality of service (QoS) requirements. ATM requires adequate and flexible traffic control schemes to meet the QoS requirements. Call Admission Control (CAC) is the most important component in the traffic control frame work. CAC is a control mechanism whose specific goal is to maintain a fine balance between the two contradictory objectives of maximising network utilisation and delivery of QoS (performance) guarantees to connections in progress. It is basically a decision algorithm which on receipt of a new connection request determines whether or not to admit the connection based on the current usage level of net work resources. Most of the present day CACs are based on complex queueing models and are known to have large processing demand. The main goal was to seek for development of a performance framework by allowing comparison of various CAC approaches and solutions in a consistent and coherent manner. The objective of this thesis is to gather thoughts towards the development of such a perfor mance framework for CAC schemes. The thesis investigates the subject of connection admission control in ATM networks from the perspective of performance requirements and presents a classification of a number of existing CAC schemes based on the methods employed. |