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Quality-of-service issues in high-speed networks
Abstract
We are currently witnessing an increasing demand for new services such as video conferencing and broadcast television. The development and deployment of new technologies such as fiber optics and intelligent high-speed digital switches have made it feasible to provide these services in future high-speed networks (HSNs). These new services are, however, characterized by rather stringent quality-of-service (QOS) criteria such as bounds on end-to-end packet delay and loss. Providing guarantees on QOS for these new services in future HSNs poses a number of interesting and challenging problems. In this thesis, we address the problem of providing statistical QOS guarantees to applications in HSNs. QOS criteria for applications are typically specified on an end-to-end basis in the network. The first part of this thesis examines policies for mapping (allocating) the end-to-end requirement to nodal requirements. This mapping simplifies providing QOS guarantees as also connection admission algorithms. The allocation policy performance is gauged on the basis of the maximum supportable network load under that policy. We develop good insight into allocation policy performance with the aid of a novel nodal sensitivity measure. It is shown that for a QOS metric of interest, the loss probability, and network operating regimes of practical interest rather naive policies exhibit near optimal performance. However, for certain other QOS metrics and operating regimes, it is shown that the optimal policy significantly outperforms simple QOS allocation policies. In the second part of this thesis, we restrict our attention to an isolated node and focus on appropriate QOS criteria and mechanisms to guarantee these criteria at the nodal level. Two new QOS criteria, the customer-duration-based and interval-based criteria, are proposed for HSNs and their applications. Further, a new cumulative transient metric, the customer average, is proposed for queueing models of communication systems. The computation of the new metric is detailed for a class of simple queueing models. Further, it is shown how this new metric enables one to compute and guarantee the new proposed QOS criteria.
Subject Area
Electrical engineering|Computer science
Recommended Citation
Nagarajan, Ramesh, "Quality-of-service issues in high-speed networks" (1993). Doctoral Dissertations Available from Proquest. AAI9408320.
https://scholarworks.umass.edu/dissertations/AAI9408320