| Multimedia applications are becoming popular over the Internet, on wireline as well as on wireless networks. Since most of these applications have high requirements for QoS, admission control and resource management become important for flow control. Several differentiated admission control schemes are introduced, with emphasis on trunk reservation and maximum threshold . Layered compression algorithms for multimedia data have been proposed to compress video/audio into two or more layers, each one as an enhancement of the former, so that when bandwidth is stringent, only those essential layers are transmitted. By combining them, differentiated admission control with adaptable reservation (DAC/AR) turns out to be a simple and efficient scheme for multi-layered data transmission. Performance is evaluated with two approaches: mathematical analysis and computer simulation. Both approaches show that DAC/AR can effectively reduce the call blocking probability (rejection rate) as well as provide differentiated services for traffic classes with different priorities. Besides, the results of simulation and analysis are compared. Network penalty and average adaptation percentage are proposed to evaluate the system performance. |
