Designing low-power wireless sensor networks

In the ever growing area of wireless sensor networks it is very important to estimate the energy usage of sensor nodes, especially if they should be powered by a battery. Often the accumulated energy consumption of a message delivery across the whole network is of interest too, in order to estimate battery life times, since message forwarding needs energy too. For rapid development cycles, fast but accurate simulations are needed. The approach presented in this paper uses transaction level modeling (TLM) to speedup simulation of wireless communication systems. The fundamental idea is that air communication can be modeled similarly to a multi master bus. Nodes are simulated by employing a multi-threaded instruction set simulator (ISS) and models of the peripheral components. The energy usage for sensing, receiving and transmitting can be estimated in the simulation and this information can then be attached to TLM messages for accumulation related to messages. The example use case throughout this paper is a tyre pressure monitoring system. The modeling and simulation is done in SystemC.