John Ankcorn

A system architecture for managing mobile streaming media services

A mobile streaming media content delivery network (MSM-CDN) overlay system provides a scalable method for delivering media streams to a large number of clients. With the availability of such a streaming infrastructure, it becomes possible to implement enhanced media services. For example, the wide range and variability of network conditions, as well as processing and display capabilities of these devices will effectively require media streams to be adapted in the network. Each streaming session needs to be tailored to these changing environments in a practical and scalable manner. Media transcoding services can be performed by the servers of the MSM-CDN overlay, providing this flexibility. Due to the computational and bandwidth requirements of real-time video transcoding, these services require management of the placement of these tasks on the most appropriate servers, to make best use of the distributed resources available within the network. In this paper we address the media service assignment problem using the notion of service-location management (SLM). An effective load balancing system requires appropriate resource monitoring. We propose alternate SLM resource monitoring schemes. Using media transcoding as a representative service, we compare the performance of these schemes on an MSM-CDN testbed. We present our conclusions on which of these alternate implementations is both most reliable and most extensible to serve a large numbers of mobile client requests.

Architecture of a modular streaming media server for content delivery networks

A mobile streaming media content delivery network can facilitate the access of rich multimedia streams by mobile users on next generation wireless networks. A principal component of this network is the edge servers that cooperate to provide streaming functionalities. This paper describes some of the design requirements for such servers. It then describes the architecture of such a streaming content, a modular design, and an intelligent scheduler for providing better video quality in varying network conditions. Finally, preliminary performance results are shown.

A Lightweight UI Software Infrastructure for Wrist-Based Displays: If Your Microwave Oven Could Talk to Your Watch, What Would It Say?

Supporting a rich array of information sources is a key element to making highly mobile computing devices usable by the wider community. It is our belief that there will not be one specific killer application for this form of computing device, but an array of applications that the user can easily access. These applications will be context sensitive and associated with a range of activities. We have developed a custom watch platform that acts as a display for presenting this type of information to the user. In order to make the watch as small and low powered as possible, we have offloaded the processing onto an external mobile device we term a personal server, which is also carried by the user. We present our lightweight software infrastructure supporting a wrist-based display communicating with a portable personal server