SFB 627: Nexus
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SFB 627: Nexus
Project B3:

Hybrid Model Management

Deutsche Version
Prof. Dr. rer. nat. Dr. h. c. Kurt Rothermel

Universität Stuttgart
Institute of Parallel and Distributed Systems
Universitätsstraße 38
70569 Stuttgart

Tel. +49 (0)711 7816 434
Fax +49 (0)711 7816 424


The consideration of hybrid structures plays a central part in the second funding period of the SFB. These systems are communication networks consisting of high-capacity context servers and ad-hoc networks which are in effect a multitude of mobile and exclusively wireless connected devices (Personal Digital Assistants, cell phones). In this context project B3 deals with the enhancement and optimization of the infrastructureless model management based on the results of the first funding period. On the other hand project B3 examines new strategies and methods for transforming the infrastructureless model management into an efficient and scalable overall system.

Allocation of Model Data

During the first funding period we analyzed how dynamic model data can be efficiently managed solely through the co-operation of mobile devices. The provisioning of model data will be expanded by considering quality characteristics based on the already developed algorithms for providing partial models on single storage nodes. This enables us to provide partial models with well-defined quality demands (e.g. timeliness or completeness of partial models) on the nodes. The availability of up-to-date, complete and consistent partial models is an important requirement for all types of data access on the model data.

Processing of Spatial Queries

As well as in the first funding period project B3 will continue to analyze the processing of spatial queries on the foundation of the provided model data. Diametral to the examination of a geometric location model in the first funding period, the focus of the second period will be expanded to symbolic location models. Thus it will be possbible to add symbolic identifiers to spatial queries which are oftentimes preferrably to complex geometrical descriptions in the interior (e.g. auditorium). Again it will be necessary to consider the quality of model data as quality characteristics have a significant impact on the quality of query results, which is especially true for the inaccuracies of positioning information combined with symbolic identifiers.

Hybrid Systems

In the course of the extension of the model management towards hybrid system structures, project B3 also covers methods that allow the integration of infrastructureless and infrastructure-based model managements into an efficient and scalable overall system. One of the first steps is to analyze how high performance of the model management can be achieved. For this, adaption methods and the assisted ad-hoc paradigm are used in particular. This takes infrastructureless management components into account in order to accomplish a robust administration of the model data in the ad-hoc network in the event of a network partitioning by using infrastructure-based communication pathways on a short notice. By evaluating the processing of spatial queries we will finally examine how a transparent model management integration can be implemented. This is a direct link to the context broker of project B5, which will effectuate a relay of model data across hybrid system boundaries.


- Institute of Parallel and Distributed Systems    
  Distributed Systems Research Group    


- Project Head    
 - Prof. Dr. rer. nat. Dr. h. c. Kurt Rothermel   
 - Dr. Pedro Marron   
- Research Assistants    
 - Dipl.-Inf. Dominique Dudkowski   
 - Dipl.-Inf. Harald Weinschrott