Multimedia QoS adaptation for inter-tech roaming

Abstract

We introduce a scalable application-level QoS adaptation service for roaming between wireless networks that are based on different technologies' ( 'inter-tech ' roaming). The service is part of a platform that supports the distribution of multimedia streams (e.g., a streamed TV channel) to mobile clients operating in a heterogeneous environment. Central to our approach is the notion of a service class, which is a domain-spec$c perceptual QoS level. Each domain in a wireless infrastructure must support a limited number of these service classes. Our adaptation service handles inter-tech roaming by handing a client off from one service class to another. In this paper, we focus on the design of the adaptation service's client-side components. They combine the loss characteristics of the client's network interfaces with configurable policies to decide when to initiate a handoff to a target service class and when to complete it. We conclude with some experimental results.

A mobility-aware broadcasting infrastructure for a wireless internet with hotspots

“…We expect that we will be able to realize seamless handoffs, as we will reuse the implementation of [4] that hands a mobile host off from one stream to another. The prototype software will be validated on the wireless testbed at the University of Twente [35], which provides a multi-domain 802.11, UMTS, and GPRS environment.…”

“…The latter may be subject to a handoff policy [3,4]. Mechanisms that move a mobile host to another media server and handoff policies are however outside the scope of this paper.…”

“…In this paper, we consider the problem of adaptively delivering live multimedia broadcasts (e.g., TV, radio, or e-cinema broadcasts) to a potentially large number of mobile hosts that roam about in a wireless internet with hotspots [1][2][3][4]. Our approach is user-oriented and is based on a managed multidomain application-level delivery infrastructure that is mobilityaware and offers broadcasts in configurations that are optimized for wireless links and mobile hosts ('mobile friendly' configurations).…”

Delivering Live Multimedia Streams to Mobile Hosts in a Wireless Internet with Multiple Content Aggregators

“…A switch between aggregators may involve transferring application-level context information (e.g., the state of a predictive encoder) between media servers [33]. In addition, it may also involve a policy-controlled handoff (e.g., [15,41]) between subnets (e.g., between the UMTS and 802.11b subnets of figure 3). Application-level context transfers and handoff policies are however outside the scope of this paper.…”

Smart download on the go: a wireless Internet application for music distribution over heterogeneous networks

“…Mobile clients should be able to seamlessly operate, also in a heterogeneous wireless environment where different mobile network technologies (e.g., 802.11, 3G, satellite, etc.) can alternatively offer the wireless access to the available music showers [5].…”