The PicoRadio project strives to develop the range of technologies necessary for the realization of ultralow energy wireless sensor networks. These include the study of multi-hop networks, and media-access layers that support low variable-rate data transmission while ensuring energy-consumption levels that are close to the theoretical limits. The target is to create a node that consumes 50-100 uW to operate. This power consumption would allow it to power itself from the energy sources of the operating environment.
Other issues involve the choice of the implementation platforms and chip architectures that enable the implementation of these advanced algorithms. A heterogeneous combination of programmable, configurable, and fixed components seems to be a probable solution. Mapping the advanced networking and communication algorithms onto such an architecture presents a real design methodology problem. Ensuring and verifying that these distributed and embedded systems will behave in a correct manner is especially hard. In addition, implementing an RF front-end that meets the demands of variable bit-rates and energy-efficiency opens some interesting new venues for research.
The ever evolving scaling of the semiconductor technology has enabled new opportunities to provide both flexibility and efficiency, as needed for these self-configuring and adaptive wireless networks, at a low cost and small size. When reducing the minimum feature sizes into the deep sub-micron realm (0.25 um and below), it becomes possible to
integrate more than one million gates on a single die, enabling the co-integration of the interfacing, computation, position location, and communication functions into a single silicon circuit. This system-on-
a-chip (SOC) approach not only maximally reduces the size of the sensor node, but also allows the use of advanced circuit architectures which provide the optimal trade-off between flexibility and energy-efficiency. The tight integration of communication and computation functions into a single integrated circuit will provide the desired functionality at the lowest possible cost and energy.