Configurable services for mobile users

Mobile devices, such as cellular phones, personal digital assistants (PDAs), and organizers, are becoming increasingly popular. Due to the high volatility of those devices, the achievable quality-of-service (QoS) for mobile services can hardly be predicted. Even for one particular type of device - say a PDA - the implementation of a mobile service may use different communication interfaces over time (i.e.; wireless LAN, IrDA). Within this paper we present a new approach towards configuration of component-based services for mobile systems. Starting from a XML-based configuration language, which defines a set of rules for component configuration depending on a number of environmental parameters, our approach allows for instantiation and configuration of components. In contrast to many other approaches targeting distributed multimedia-style application on PC-class computers, our framework focuses on the extension of distributed services onto mobile devices. As proof-of-concept scenario we have implemented a configurable distributed video surveillance application on the basis of the Microsoft Distributed Component Object Model on Windows 2000 and on the Windows CE-based Pocket PC platform