Arjan J. H. Peddemors

An Extensible Network Resource Abstraction for Applications on Mobile Devices

Mobile devices are increasingly equipped with multiple network interfaces that can dynamically support access to different kinds of wireless and fixed networks. Dealing with these dynamics and heterogeneity is challenging for many types of applications running on mobile devices and is hindered by the lack of a consistent overview of available network resources. In this paper we present a system service which offers an extensible network resource abstraction to applications running on a mobile device. It can be used in conjunction with well-known APIs that provide access to these resources. We argue that the cross-layer and mobility reflecting transparency introduced by the model underpinning this abstraction is essential for applications that need to dynamically adapt to changes in available network resources. Ease of adaptation may reduce the reliance on dedicated mobility management protocols. Furthermore, we show that different types of mobile applications may use this abstraction at various levels of detail, to match their specific decision making needs. We introduce the architecture of the service, discuss experiences with its reference implementation, and show how the system can be extended to accommodate new network technologies. Experiments with a real-world application indicate that uncomplicated application logic suffices for a dynamic network environment.

A System Perspective on Cognition for Autonomic Computing and Communication

In this paper we present a conceptual view on the incorporation of cognitive processing capabilities in future generation computer systems. We argue that cognition is at the heart of autonomic behavior, and therefore a necessary ingredient for autonomic computing and communication. We introduce a bio-inspired cognitive engine that interacts with and has control over major operating system components, and showcase, based on scenario descriptions, how communicating applications take advantage of this setup by adapting and autonomously reacting to changes in heterogeneous and widely varying network resources. As a conceptual work, this paper does not cover experiences with the implementation of the introduced concepts, nor does it describe experimental results

A high performance distributed database system for enhanced Internet services

Abstract Using a distributed database system as a part of the distributed web sever architecture has obvious advantages. It is shown that a first phase distributed database system can be build by extending an existing object oriented database system with application-specific additions. A web database is implemented, as a part of the traditional HTTP-based distributed web server, using this distributed database system.

Managing Mobility in Beyond-3G Environments

Beyond 3G (B3G) environments typically consist of multi-homed terminals and wireless overlay networks. This paper presents a categorization of IP-level mobility management solutions for B3G environments. Closely observing the mobility requirements of a wide range of possible applications, the paper also motivates the consideration of a new mobility management approach in B3G environments, whereby location management (i.e., reaching mobile end-users at the IP-level for session invitations) is decoupled from handover management (i.e., switching ongoing sessions, collectively or individually, to another access network whenever appropriate). For example, one can use cellular GPRS/UMTS networks for location management and Wi-Fi? or cellular networks for handover management. The paper elaborates upon the merits of such so-called context-aware mobility solutions, which are attained from an optimum use of the mobility management features embedded in the underlying infrastructure.

A High Performance Distributed Database System for Enhanced Internet Services

Using a distributed database system as part of a distributed web server architecture has obvious advantages. It is shown that a first phase distributed database system can be build by extending an existing object oriented database system with application specific additions. A web database is implemented, as part of a traditional HTTP based distributed web server, using this distributed database system.

Handling heterogeneity in context aware services

The increasing number of context aware services, which depend on various multimodal sensing, processing and actuating techniques, technologies and formats ask for a physical framework that is able to handle their heterogeneity. Thereto, we propose a context model bridging the semantic gaps between context aware services. In addition we propose a simple system architecture of Distribution Servers and Transformation Servers that bridge semantic gaps among context aware services. Applying our framework we solve the heterogeneity problem existing for location services. Location is typically a form of context where heterogeneity is a problem.