Wednesday, 13. July 2011 13.07.11 15:40 Age: 7 Jahre

Data from the proximate neighborhood
The research group Computer Networks researches aggressive Caching

Photo (Simone Rudolph): Martin Dräxler M.Sc., Frederic Beister M.Sc. and Prof. Dr. Holger Karl in “search” of cached data.

Paderborn. Presently in the society of communication, nearly everyone owns at least one mobile phone which they use actively for different reasons. For a long time the mobile phone has been more than just a tool for communication, or perhaps even SMS, as it is also used for reception and watching videos. The data rate, which has to be surmounted, increases enormously with the ascending amount of existing mobile phones and the changing consumption behavior, which is even more complex with the distribution of films and pictures that goes along with it. In the meantime, in order to convey this high volume of data, the huge mobile telephone systems have installed (in each case) about 100,000 base stations in Germany (with an increasing tendency due to LTE). Because these stations operate around-the-clock, the energy consumption is immense. Up until now this consumption and its costs, which are produced within the nets, were irrelevant – but this is about to  change. In order to increase the energy efficiency through optimization of the wireless technology ComGreen (Communication Green) was launched at the beginning of the year.

The University of Paderborn participates in this project conjointly with four other collaboration partners. Professor Dr. Karl and his assistants, Frederic Beister and Martin Dräxler, are part of the research group Computer Networks for the Department of Computer Science. They are searching for options to influence the configuration of the access network in the mobile telephone system in order to decrease the energy consumption by as little as possible. Furthermore, it is in their particular interest to continue the shutdown of the base stations, which takes up most of the energy. To ensure that the same data rate is still provided after the shutdown the research group has considered optimizing the core network. “The question is how to configure and operate the net so that the data still arrives in the right place, even if the base station is going to be shut down” explains Karl.

One option to release the base stations is shortening the transport distances of the data. In this context, the research group analyses approaches like the Information Centric Networking, to which the so called aggressive caching belongs to as well. This places the popular data near to the user where it is required. In order to activate the cache systematically the power consumption of the device has to be determined beforehand. The research group therefore works on a role model which is able to foretell the energy consumption. The utilization of caches could, via the allocation of the bundled data, save energy on the long term.

The goal of the research group is not to merely switch base stations –respectively the belonging components – on and off, but to develop a power-saving mode for the whole communication system. “Up to now you can only save energy by shutting down – but this is not what we want”, says Frederic Beister. “We already want to do something before that.” They want to emerge a solution from the project which can cover and optimize the whole system.

Besides the University of Paderborn the Deutsche Telekom Laboratories, the Ericsson GmbH, the Fraunhofer Association for Applicational Research e.V. and the Technische Universität Berlin all take part in the project.  The project is funded by the Federal Ministry of Economics and Technology for a span of two years.

Prof. Dr. Holger Karl
Research Group Computer Networks
05251 60-5375