Minimizing energy consumption for wireless computers in Moby Dick

The Moby Dick project is a joint European project to develop and define the architecture of a new generation of mobile hand-held computers, called Pocket Companions. The Pocket Companion is a hand-held device that is resource-poor, i.e. small amount of memory, limited battery life, low processing power, and connected with the environment via a network with variable connectivity. Because the battery life is limited and the battery weight is an important factor for the size and the weight of the Pocket Companion, energy management plays a crucial role in the architecture. In our architecture we apply several supplementary power reduction techniques on all levels of the system, including the operating system and applications. The two main themes are: (1) to avoid wasteful activity, and (2) to exploit the locality of the reference. We put considerable effort in reducing the energy consumption of the communication interfaces. There are several ways to reduce the energy consumption: e.g. by system decomposition, using hybrid networking, and by applying power aware MAC protocols.