v3.0, 20040325, ME
Session A Saturday, May 8 09:30 h–11:30 h
AUDIO NETWORKING
Chair: Thomas Sporer, Fraunhofer IIS AEMT, Ilmenau, Germany

A-1 An XML-Based Approach to the Generation and Testing of mLAN Sound Installation Configurations—Jun-ichi Fujimori, Yamaha Corporation, Hamamatsu, Japan; Rob Laubscher, Otic Systems, Cape Town, South Africa; Richard Foss, Rhodes University, Grahamstown, South Africa
An application, called the mLAN Installation Designer, has been developed that enables the user to graphically design and validate an mLAN sound installation. This application is built upon a model of mLAN systems that is defined by an Extensible Markup Language (XML) schema, ensuring cross platform portability and future scalability. The XML schema provides sufficient flexibility to form the basis for a standard effort to describe the configuration of IEEE 1394-based sound installation environments. The output from the mLAN Installation Designer application file is an XML document, consistent with the defined schema, which allows a configuration tool to configure the mLAN devices for automatic operation during deployment of the system.
A-2 Plug and Play? An Investigation into Problems and Solutions of Digital Audio Networks—Christian Frandsen, TC Electronic A/S, Risskov. Denmark; Morten Lave, TC Applied Technologies Ltd., Markham, Ontario, Canada
It is a challenge to predict fault tolerance of the total system using point-to-point digital audio interfaces to build complex routing structures. In real life, digital interfacing is therefore still considered less robust than analog. This paper provides a systematic investigation of factors determining reliability in a number of widely used professional audio and synchronization interfaces such as AES3, SPDIF, ADAT, TDIF, and World Clock. Electrical characteristics, phase-offset and tolerance to offset, intrinsic jitter and tolerance to jitter, and sample rate precision have been tested. Additionally, compliancy with standards has been evaluated. Finally, a discussion of how these problems can be dealt with followed by specific thoughts about the next generation of interfaces will be presented with examples.
A-3 Delivering High-Quality Audio over WLANs—Andreas Floros, Theodore Karoubalis, ATMEL-Hellas S.A., Multimedia & Communications Group, Patras, Greece
Based on the current version of the forthcoming IEEE802.11e standard, the paper examines the wireless, real-time transmission of high-quality audio streams. The required procedures that provide the necessary Quality of Service (QoS) support are presented and optimized for digital audio applications, and their effect on the achieved playback quality is estimated through a sequence of tests in terms of the achieved wireless bit rate and the end-to-end packet delay. Both two-channel and multichannel audio playback setups are considered in order to accurately simulate typical stereo and home theater wireless applications.
A-4 Advances in Sinusoidal Analysis/Synthesis-Based Error Concealment in Audio Networking—Sang-Uk Ryu, Kenneth Rose, University of California, Santa Barbara, CA, USA  
This paper investigates error concealment based on sinusoidal analysis and synthesis. Major shortcomings are identified with focus on the extraction of sinusoidal frequency evolution and sinusoid matching. A new approach to frame loss concealment is proposed. It involves parallel Fourier transformation with long and short windows to accurately extract model parameters and is complemented with two sinusoid matching techniques—sinusoidal pair alignment by dynamic programming and harmonics-based matching. Moreover, due to the incompatibility of sinusoidal representation with broadband, noise-like signals, an alternative “sinusoids plus residual” model is incorporated. The new algorithm was applied to CD-quality audio of various genres and was demonstrated to improve the perceptual quality with considerable gains for nontransient frames.