A QoS adaptive multimedia transport system: design, implementation and experiences

Abstract

The long awaited 'new environment' of high speed broadband networks and multimedia applications is fast becoming a reality. However, few systems in existence today, whether they be large scale pilots or small scale test-beds in research laboratories, offer a fully integrated and flexible environment where multimedia applications can maximally exploit the quality of service (QoS) capabilities of supporting networks and end-systems. In this paper we describe the implementation of an adaptive transport system that incorporates a QoS oriented API and a range of mechanisms to assist applications in exploiting QoS and adapting to fluctuations in QoS. The system, which is an instantiation of the Lancaster QoS Architecture, is implemented in a multi ATM switch network environment with Linux based PC end systems and continuous media file servers. A performance evaluation of the system configured to support video-on-demand application scenario is presented and discussed. Emphasis is placed on novel features of the system and on their integration into a complete prototype. The most prominent novelty of our design is a 'distributed QoS adaptation' scheme which allows applications to delegate to the system responsibility for augmenting and reducing the perceptual quality of video and audio flows when resource availability increases or decreases.

Distributed multimedia service composition with statistical QoS assurances

“…It then selects the best qualified ServFlow based on the resource and QoS states collected by the probes. We will discuss this step in detail in Section III-E. 4 The BCP initiator can also be the destination or a third-party overlay node. Step 4.…”

Quality-of-Service Adaptive Control of Multimedia Services in Short-Term Resource Reservation Networks

“…Most of the QoS adaptation models (Campbell and Coulson 1997;Campbell et al 1995;Cowan et al 1995;Hafid and Bochmann 1997;Malamos et al 1999Malamos et al , 2001Malamos et al , 2002 achieve application adaptation control through provider-user negotiations, where the user is informed about the network constraints and the quality levels that could be supported and decides about the preferred quality. However, these methods require long-term resource reservations to implement, which is feasible but cannot be supported by the most extensively used networks.…”

The deployment of end-to-end available bandwidth estimation mechanism in web-based application

“…In the past, there have been several proposals [3,4,5,6,7] that provides different QoS requirements for users and applications. However, these proposals unable to provide the end-hosts or applications a mechanism that can dynamically detect and adapt the variability of network conditions.…”