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Future smart mobile has to be a true chameleon

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21.01.2004

By continously adapting the receiver settings of a mobile phone to the current conditions, the advantage is twofold; facing bad reception, the connection can be improved while in good conditions, the energy consumption can be reduced. This is possible by an automatic controller developed by Lodewijk Smit of the University of Twente in The Netherlands. Smit did his PhD work on this, within the Centre of Telematics and Information Technology (CTIT).

The mobile connection can be optimized by frequently evaluating the quality and adapting the receiver of the mobile device to this level. The conditions are continuously changing. Hence, the quality of the reception is fluctuating. Modern phones will adapt to the service level required (speech, data or video) and not to the reception quality.
By using the advanced control method Smit has developed, the amount of calculation the receiver has to perform, can be decreased drastically. “In this way, it doesn’t have to work harder than strictly necessary. In bad conditions, this means using all resources for the actual signal, thus saving energy. In fair or good conditions, this means saving the battery. This is a major advantage as well. New applications put a growing strain on the battery, while the battery is not improving at the same speed.”

Lodewijk Smit started with a method for evaluating the quality in a simple and accurate way. Current methods send a lot of information over the mobile network, apart from the actual data, before quality level is determined. Smits method decreases this amount of overhead. He calculates a statistical analysis of the data received, to evaluate the probability that a sent symbol is received in the wrong way. The receiver can then be adjusted until the error level is obtained. A limited number of remaining errors is acceptable, as there are standard error-correcting codes in wireless and mobile communication.

Furthermore, Smit is able to predict the influence of the changed settings on energy consumption and connection quality. Up to now, this is not possible without complex calculation models. A major difference with current approaches is that Smit performs a global optimization of the various parts of the receiver. Usually, the parts are optimized separately: this is not necessarily an optimization of the whole.

The research is part of the CHAMELEON-project of the Centre of Telematics and Information Technology (CTIT) of the University of Twente. Within this context, new architectures are developed for energy-efficient architectures of mobile equipment. Too often, according to the CTIT-researchers, mobile devices are designed in basically the same way as desktop devices in which energy consumption is not an issue. Smit expects his method to be easily integrated into the circuits of new generations of mobiles.

Wiebe van der Veen | Source: alphagalileo
Further information: www.cs.utwente.nl/~smitl

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