Mini-Course 6: Dynamic Networks
Christian Scheideler
Overview
In this mini-course we will present various models and techniques for communication in dynamic networks. Generally speaking, dynamic networks are networks of dynamically changing network characteristics such as bandwidth or topology. There are many scenarios in which dynamic networks occur. For example, a fixed interconnection network might experience (adversarial or random) faults, or we may have a wireless network formed by users that move around. Also, the Internet can be seen as a dynamic network, since some virtual connections or communication links might experience large differences in their availability over time, offering a low bandwidth at one time and a high bandwidth at another time.
Basic questions in the area of dynamic networks that will be investigated in the mini-course are:
- How to ensure connectivity? Here, we will look at the problem of how to choose connections between the hosts of a wireless network to ensure connectivity. In addition, we will investigate how to connect the hosts to ensure the existence of a route of near-minimum energy consumption between any two hosts.
- How to ensure uninterrupted service? Here, we will concentrate on how to ensure uninterrupted information flow in faulty networks. Our approach will be based on choosing multiple disjoint paths for each request. The problem we will study is, how to select multiple disjoint paths for each request so that the number of accepted requests is as close to optimal as possible.
- How to achieve a high throughput? We will look at models for networks with a highly dynamic topology that is under adversarial control, and we show that even for these networks online routing algorithms can be designed that achieve a near-optimal throughput.
- How to perform admission control? In highly dynamic networks it may not be possible for the nodes to decide in advance whether or not a packet (or packet stream) can be successfully routed to a destination. Therefore, strategies are needed that can do this while the packets travel through the network so that a throughput close to a best possible throughput with perfect admission control decisions at the sources can be achieved. We will present and analyze such a strategy.
Each of these questions will be given one day. The presentations will be based on the following papers:
- Tuesday, July 2:
- Tamás Lukovszki. New Results on Geometric Spanners and Their Applications. Ph.D. Thesis, Paderborn University, 1999. (compressed postscript)
- Friedhelm Meyer auf der Heide, Christian Schindelhauer, Klaus Volbert, and Matthias Grünewald. Congestion, Energy and Delay in Radio Networks. In Proc. of the 14 ACM Symposium on Parallel Algorithms and Architectures (SPAA), 2002. (compressed postscript)
- Matthias Grünewald, Tamás Lukovszki, Christian Schindelhauer, Klaus Volbert. Distributed Maintenance of Ressource Efficient Wireless Network Topologies. To appear in Proc. of the 8th Euro-Par Conference (EuroPar'2002), LNCS Springer Verlag, 2002. (compressed postscript)
- Thursday, July 4:
- P. Kolman and C. Scheideler. Simple On-Line Algorithms for the Maximum Disjoint Paths Problem. In Proc. of the 13th ACM Symposium on Parallel Algorithms and Architectures (SPAA), pp. 38-47, 2001. (compressed postscript)
- P. Kolman and C. Scheideler. Improved Bounds for the Unsplittable Flow Problem. In Proc. of the 13th ACM-SIAM Symposium on Discrete Algorithms (SODA), 2002. (compressed postscript)
- Amitabha Bagchi, Amitabh Chaudhary, Petr Kolman, and Christian Scheideler. Algorithms for Fault-Tolerant Routing in Circuit Switched Networks. In Proc. of the 14 ACM Symposium on Parallel Algorithms and Architectures (SPAA), 2002. (compressed postscript)
- Tuesday, July 9:
- B. Awerbuch, P. Berenbrink, A. Brinkmann, and C. Scheideler. Simple Routing Strategies for Adversarial Systems. In Proc. of the 42nd IEEE Symposium on Foundations of Computer Science (FOCS), pp. 158-167, 2001. (compressed postscript)
- Thursday, July 11:
- B. Awerbuch, A. Brinkmann, and C. Scheideler. Anycasting and Multicasting in Adversarial Systems: Routing and Admission Control. Technical report (recently submitted), 2002. (compressed postscript)
Christian Scheideler
Last modified: Thu Apr 11 2002