Measuring the arrival quality of real-time packet trains - a global perspective and its real-time application
Speaker:Dr. Ulrich Speidel
Senior Lecturer
Department of Computer Science, University of Auckland
Date & Time:9 Apr 2013 (Tuesday) 16:00 - 17:00
Organized by:Department of Electrical and Computer Engineering


Real-time applications on the Internet include everyday applications such as Voice over IP telephony, but also more advanced technologies such as remote manipulation, e.g., for remote surgery. These applications work best if their packet trains arrive with minimum latency, low packet loss, constant inter-arrival times and all packets in the order in which they were transmitted. Latency is largely unavoidable due to the physical distance, but not meeting the remaining requirements perfectly requires applications to buffer packets until sufficient data for meaningful processing (e.g., audio playback) has accumulated at the receiver. Conventional "improvements" to Internet infrastructure, such as the addition of new links and load balancing can be a double-edged sword: While they create extra bandwidth and reduce congestion and sometimes latency, they also create additional router queues and alternative paths, potentially affecting inter-arrival times and in-order delivery. This is in particular a problem if the destination is served by long thin networks. Our project is a longitudinal study that attempts to track the long-term global trend in the arrival quality of real-time long distance packet streams. Such an advanced novel technology might be applied to various applications including internet-based real-time e-healthcare.


Ulrich Speidel is a senior lecturer in the Department of Computer Science at the University of Auckland. Born in Germany, he holds an MSc in Physics and a PhD in Computer Science from the University of Auckland. His research interests originate in information theory and the application of information measures in a number of fields, including in signal processing, digital communication and computer networking.