Stuart Goose

A 3D audio only interactive Web browser: using spatialization to convey hypermedia document structure

Interactive audio browsers provide both sighted and visually impaired users with access to the WWW. In addition to the desktop PC, audio browsing technology can be deployed that enable users to browse the WWW using a telephone or while driving a car. This paper describes a new conceptual model of the HTML document structure and its mapping to a 3D audio space. Novel features are discussed that provide information such as: an audio structural survey of the HTML document; accurate positional audio feedback of the source and destination anchors when traversing both inter-and intra-document links; a linguistic progress indicator; the announcement of destination document meta-information as new links are encountered. These new features can improve both the users comprehension of the HTML document structure and their orientation within it. These factors, in turn, can improve the effectiveness of the browsing experience.

A situated computing framework for mobile and ubiquitous multimedia access using small screen and composite devices

In recent years, small screen devices, such as cellular phones or Personal Digital Assistants (PDAs), enjoy phenomenal popularity. PDAs can be used to complement traditional computing systems to access personal multimedia information beyond the usage as digital organizers. However, due to the physical limitations accessing rich multimedia contents and diverse services using a single PDA is more difficult. Hence, the Situated Computing Framework (SCF) research project at Siemens Corporate Research (SCR) aims to develop a ubiquitous computing infrastructure that facilitates nomadic users to access rich multimedia contents using small screen devices. This paper describes a new distributed computing concept, the Small Screen/Composite Device (SS/CD) framework, which offers mobile users new classes of ubiquitous and mobile multimedia services without to limit the diversity and the richness of the provided services.

An Overlay Architecture for High-Quality VoIP Streams

The cost savings and novel features associated with voice over IP (VoIP) are driving its adoption by service providers. Unfortunately, the Internets best effort service model provides no quality of service guarantees. Because low latency and jitter are the key requirements for supporting high-quality interactive conversations, VoIP applications use UDP to transfer data, thereby subjecting themselves to quality degradations caused by packet loss and network failures. In this paper, we describe an architecture to improve the performance of such VoIP applications. Two protocols are used for localized packet loss recovery and rapid rerouting in the event of network failures. The protocols are deployed on the nodes of an application-level overlay network and require no changes to the underlying infrastructure. Experimental results indicate that the architecture and protocols can be combined to yield voice quality on par with the public switched telephone network

1-800-OVERLAYS: using overlay networks to improve VoIP quality

The cost savings and novel features associated with Voice over IP (VoIP) are driving its adoption by service providers. Such a transition however can successfully happen only if the quality and reliability offered is comparable to the existing PSTN. Unfortunately, the Internets best effort service model provides no inherent quality of service guarantees. Because low latency and jitter is the key requirement for supporting high quality interactive conversations, VoIP applications use UDP to transfer data, thereby subjecting themselves to performance degradations caused by packet loss and network failures.In this paper we describe two algorithms to improve the performance of such VoIP applications. These mechanisms are used for localized packet loss recovery and rapid rerouting in the event of network failures. The algorithms are deployed on the routers of an application-level overlay network and require no changes to the underlying infrastructure. Initial experimental results indicate that these two approaches can be composed to yield voice quality on par with the PSTN.

Composite Device Computing Environment: A Framework for Situated Interaction Using Small Screen Devices

Abstract: Contemporary small screen devices are used as personal companion or communication devices. However, their physical dimensions constrain the processing, communication and user interface capabilities. Thus, rich content presentation and diverse service access via small screen appliances is limited accordingly. This paper introduces the Composite Device Computing Environment (CDCE) that provides a framework for dynamically detecting and utilising surrounding computing resources to overcome the small screen device limitations. CDCE includes the communication infrastructure in addition to supporting alternative models for interactivity between small screen clients and surrounding computing resources.

Resilience technologies in Ethernet

In choosing a network service technology, a subscriber considers many features such as latency, jitter, packet loss, security, and availability. The most important feature, and usually the one that determines the final selection, is the service availability. In this article, a full spectrum of applications are studied, ranging from the minimal constraints of home networks to the rigorous demands of Industrial Ethernet Networks. This is followed by a thorough examination of Ethernet layer resilience technologies. This paper provides the resilience characteristics that are key for each class of application

Streaming speech 3 : a framework for generating and streaming 3D text-to-speech and audio presentations to wireless PDAs as specified using extensions to SMIL

While monochrome unformatted text and richly colored graphical content are both capable of conveying a message, well designed graphical content has the potential for better engaging the human sensory system. It is our contention that the author of an audio presentation should be afforded the benefit of judiciously exploiting the human aural perceptual ability to deliver content in a more compelling, concise and realistic manner. While contemporary streaming media players and voice browsers share the ability to render content non-textually, neither technology is currently capable of rendering three dimensional media. The contributions described in this paper are proposed 3D audio extensions to SMIL and a server-based framework able to receive a request and, on-demand, process such a SMIL file and dynamically create the multiple simultaneous audio objects, spatialize them in 3D space, multiplex them into a single stereo audio and prepare it for transmission over an audio stream to a mobile device. To the knowledge of the authors, this is the first reported solution for delivering and rendering on a commercially available wireless handheld device a rich 3D audio listening experience as described by a markup language. Naturally, in addition to mobile devices this solution also works with desktop streaming media players.

Exploiting Location-Based Composite Devices to Support and Facilitate Situated Ubiquitous Computing

Small screen appliances, such as cellular phones or Personal Digital Assistants (PDAs), enjoy enormous popularity as is evidenced by the tremendous commercial success. One focus of the ubiquitous research community is the potential utility of this class of devices beyond that of a basic organizer or communication device. The pocket-sized requirement imposes constraints upon the computational power and user interface of these small screen devices. This paper describes the Composite Device Computing Environment (CDCE) that offers a framework for supporting nomadic users with small screen devices for the retrieval of rich contents and the access of diverse services. CDCE provides a communication network infrastructure for seeking, unifying and exploiting any surrounding devices as a means to overcome the small screen client constraints. This paper describes the architecture and reports the current status of the ongoing realization of CDCE.

Spanning tree elevation protocol

The economics and familiarity of Ethernet technology is motivating the vision of wide-scale adoption of Metro Ethernet Networks (MEN). Despite the progress made by the community on additional Ethernet standardization and commercialization of the first generation of MEN, the fundamental technology does not meet the expectations that carriers have traditionally held in terms of network resiliency, load management, and Quality of Service (QoS). We propose a new concept of Spanning Tree Elevation Protocol (STEP) that increases MEN performance while supporting QoS including traffic policing and service differentiation. STEP manages multiple Spanning Trees as a means to control the traffic flow rates and to differentiate classes of traffic. Whenever a service level agreement is compromised, STEP redirects frames of affected flows to the next spanning tree in sequence utilizing the alternate paths. As a result, the capacity in terms of network throughput is greatly enhanced while almost avoiding any reconvergence time in the case of failures. The gain ranges from 1.7% to 7.3% of the total traffic in the face of failure; while load balancing increases an additional 12.8% to 37% of the total throughput. At the same time, STEP maintains the required bandwidth for high priority traffic class during the failure scenarios and the high congestion scenarios.

Cross-over spanning trees Enhancing metro ethernet resilience and load balancing

The economics and familiarity of Ethernet technology is motivating the vision of wide-scale adoption of Metro Ethernet Networks (MEN). Despite the progress made by the community on additional Ethernet standardization and commercialization of the first generation of MEN, the fundamental technology does not meet the expectations that carriers have traditionally held in terms of network resiliency and load management. These two important features of MEN have been addressed in this paper. We propose a new concept of Cross-Over Spanning Trees (COST) that increases the resiliency of the MEN while provisioning the support for load balancing. As a result, the capacity in terms of network throughput is greatly enhanced while almost avoiding any re-convergence time in the case of failures. The gain ranges from 1.69% to 7.3% of the total traffic in the face of failure; while load balancing increases an additional 12.76% to 37% of the total throughput.