Carsten Pils

Context modelling and management in ambient-aware pervasive environments

Services in pervasive computing systems must evolve so that they become minimally intrusive and exhibit inherent proactiveness and dynamic adaptability to the current conditions, user preferences and environment. Con-text awareness has the potential to greatly reduce the human attention and interaction bottlenecks, to give the user the impression that services fade into the background, and to support intelligent personalization and adaptability features. To establish this functionality, an infrastructure is required to collect, manage, maintain, synchronize, infer and disseminate context information towards applications and users. This paper presents a context model and ambient context management system that have been integrated into a pervasive service platform. This research is being carried out in the DAIDALOS IST Integrated Project for pervasive environments. The final goal is to integrate the platform developed with a heterogeneous all-IP network, in order to provide intelligent pervasive services to mobile and non-mobile users based on a robust context-aware environment.

Using the Internet in Transport Logistics - The Example of a Track & Trace System

The paper presents some socio-economic and technical issues that arise from the design of an open, multimodal end-to-end tracking & tracing system. An outline of the general background and the projects goals is followed by a discussion of the associated socio-economic aspects. User requirements are also addressed, with respect to the business context of the logistics environment. Subsequently, a brief overview of the projects technical design choices and is given, followed by a more detailed discussion of the individual components of this architecture.

Technologische Grundlagen des Mobile Commerce

Um die Erfolgsaussichten eines Geschaftsmodells, welches auf modernen Mobilfunksystemen aufbaut, realistisch einzuschatzen, bedarf es eingehender Kenntnisse der zugrunde gelegten Technologien. Es ware z.B. derzeit wenig Erfolg versprechend einen multimedialen Dienst auf Basis von GSM anzubieten, denn weder die Kommunikationsnetze noch die Endgerate und Dienstplattformen entsprechen den Anforderungen einer solchen Anwendung. Daher wird der Begriff „m-commerce“ heutzutage in erster Linie mit einfachen Diensten fur die auf Sprachubertragung optimierten Mobilfunknetze der 2. Generation assoziiert. Beispiele hierfur sind das Herunterladen von Rufsignalen fur Mobiltelefone und der Zugriff auf Borseninformationen.

Rational Server Selection for Mobile Agents

As mobile agents have the ability to operate autonomously and in a disconnected way they are considered to suit mobile computing environments. Mobile users can dispatch agents into the fixed network where the agents operate in the users behalf. Thus, in contrast to client/server interactions agents do not suffer from poor performing wireless access networks. In this paper the performance of mobile agents and client/server interactions are analysed with respect to heterogeneous networks and server resources. It is argued that without a certain knowledge of the available resources agents can hardly decide whether they should migrate or just apply client/server calls to access a remote service. To this end, it is proposed that agents should access server selection systems in order to plan their migration strategy. However, while server selection systems process agent requests the agents are waiting idle. Thus, access to server selection systems comes at a cost and therefore agents must be careful about it. To solve this decision problem an algorithm is proposed which estimates the benefits of accessing server selection systems. Finally, the decision algorithm is evaluated with the help of a simulation model.

SECURITY CONSIDERATIONS FOR THE PARCELCALL REAL-TIME TRACKING AND TRACING SYSTEM

Although many transport and logistics companies have tracking and tracing systems, these systems typically are proprietary solutions. At the same time, supply chains are becoming increasingly complex, involving multiple carriers and transport modes. Accurate, up-to-date information exchange across different carriers and modes of transport is in high demand. The objective of the European project ParcelCall is the development of an open and standardized architecture for seamless tracking and tracing across the entire logistics and transportation chain. Security issues that arise in this context are discussed.

The performance server: rational server selection for mobile agents

As mobile agents can dynamically adapt to resource capacities they suit heterogeneous environments. That is, agents are not bound to a single host and can migrate to an outperforming one. Consequently, agent technology can balance the resources of a heterogeneous system. However, to balance resources efficiently agents must take resource load into account. Thus, to support the agent migration strategy the application of server selection systems has been proposed recently. Server selection systems keep track of the load of network and host resources and hence predict the performance of different migration strategies. Yet, server selection comes at a cost and therefore agents must take care when applying it. This paper presents a server selection system which meets the requirements of mobile agents. Moreover, in contrast to any other server selection system known from literature the new one addresses the problem of rational server selection.

Rational Server Selection for Mobile Agents: Problem Solution and Performance Analysis

Since agents have the ability to migrate to outperforming resources they can potentially balance the load of heterogeneous systems. However, to balance resources efficiently agents must take the load into account. Thus, to support the agent migration strategy the application of server selection systems has been proposed recently. Server selection systems keep track of the load of network and host resources and hence predict the performance of different migration strategies. Yet, server selection comes at a cost and therefore agents must take care when applying it. This paper presents a decision strategy for the agent’s decision problem. The performance of the approach is analysed with the help of a simple queuing model.