We investigate a state dependent multicast routing scheme, called Least Load Multicast Routing (LLMR), for single rate loss networks. The algorithm is based on Least Load Routing (LLR) concept and the approach is to select the least loaded links for establishing connections. An analytical model for LLMR is developed. The accuracy of the analytical model is compared with the simulation results and is found to be very good. We also develop a simplified analytical model for fully symmetrical networks, which is also verified by comparing with simulation results.

This paper presents the system issues involved with the transmission of pre-encoded VBR MPEG video using CBR service. Conventional wisdom suggests that lossless delivery of VBR video using CBR service requires bandwidth to be reserved at the peak rate resulting in low bandwidth utilization. We calculate the minimum rate at which bandwidth must be reserved on a network in order to provide continuous playback of an MPEG encoded video bitstream. Simulation results using the frame size traces from several pre-encoded MPEG bitstreams and several buffer sizes demonstrate that this minimum reservation rateis much lower than the peak rate when a relatively small playback buffer size is used, resulting in much higher bandwidth utilization. Procedures for performing connection setup and lossless realtime video playback between the video server and the client are outlined. Methods for incorporating VCR-like features such as pauseandfast forward/reversefor Video-on-Demand (VoD) applications are presented.

It is always difficult to monitor stringent cell loss ratio (CLR), e.g. 10-9, in asynchronous transfer mode (ATM) networks, because its measurement period is too long for real-time measurement. In this paper, we propose new performance monitoring mechanisms for stringent CLR. We consider virtual ATM switches whose resources are much smaller than the real system and thus much higher CLRs will be obtained within a relatively short measurement period. By applying some regression methods in the CLRs obtained from the virtual system, we can estimate the actual CLR of the real system quite accurately and our performance monitoring mechanisms will be operated based on the estimation. Through the numerical examples, our mechanisms are not only more accurate than the traditional methods, but also have shorter measurement periods compared with direct measurement.

Medium access control (MAC) protocol is one of the key components for providing quality of service (QoS) in wireless ATM (W-ATM) networks. In this paper, we propose a hierarchical scheduling scheme coupled with fair queueing algorithms with adaptive weights. This scheme is intended to be applicable to a TDMA/TDD based MAC protocol. Specifically, the performance of the fair-queueing algorithm using fixed weights and adaptive weights is evaluated and compared. Simulation results show that the proposed hierarchical fair-queueing scheduling with adaptive weights (HAW) can yield a lower cell transfer delay and a higher channel utilization while maintaining fairness among multiple users.