<title>End-to-end QoS support for adaptive applications over the Internet</title>

Abstract

In current end systems, multiple flexible, complex and distributed applications concurrently share and compete both end systems resources and transmission bandwidth of heterogeneous multi-protocol networks, especially the Internet. Our objective is to enable adaptation awareness in these applications to fully cope with the dynamics in resource availability over the heterogeneous Internet, as well as fluctuations in Q0S requirements of the applications themselves. In this paper, we present the theoretical and practical aspects of a Task Control Model implemented in the middleware layer, which applies control theoretical approaches to utilize measurement-based samples monitored in the network traffic, as well as resource and Q0S demand dynamics observed in the end systems.In our Task Control Model, we introduce Adaptation Tasks for controlling the adaptive behavior of applications, and Observation Tasks for measurements of traffic and end systems resources. We have made several contributions based on the Task Control Model. First, we are able to quantitatively analyze the stability and responsiveness properties of adaptive algorithms, as well as maintaining fairness properties among all applications. Secondly, we present specific translation mechanisms to theoretical output of Adaptation Tasks to semantic adaptive behavior within the applications. Thirdly, we explore necessary enabling service platforms in the middleware level to embrace the Task Control Model. Finally, the theoretical analysis in the paper is carried out in the context of a distributed visual tracking application, in order to demonstrate the effects of adaptation in real systems.

QoS Adaptation in Multimedia Multicast Conference Applications for E-Learning Services

“…In fact, if some critical adjustments are made on-the-fly, the result is often the collapse of the application. Nevertheless, dynamic adaptation is currently a subject of study within group communication applications (Layaida & Hagimonte, 2002;Tusch, Böszörményi, Goldschmidt, Hellwagner & Schojer, 2004).…”

Using the timely computing base for dependable QoS adaptation

“…Relatively to adaptation strategies, we mention the work in [1], that proposes adaptation among a fixed number of accepted QoS levels, and the work in [20], that uses control theory to enhance adaptation decisions and fuzzy logic to map adaptation values into application-specific control actions. Just like ours, both these works assume that the environment can be unpredictable and focus on providing middleware algorithms and mechanisms to improve the adaptation, instead of providing resource management architectures and services.…”

Synchronous E-Learning Integrating Multicast Applications and Adaptive QOS

“…Applications should be designed with adaptation in mind; they need to employ built-in mechanisms that allow them to probe the conditions of the network environment and alter their transmission characteristics accordingly (Miras, 2002). Self-adaptive applications, in the sense of proactive behavior for transmission of continuous media in multiparty applications, are a well-accepted solution due to the correct integration of new services in today's Internet (Lubonski, Gay, & Simmonds, 2005;Deusdado, 2002;Li, Xu, Naharstedt, & Liu, 1998).…”