A cross-layer design for low-power wireless sensor network

The goal of this paper is to describe the challenges which have been faced in the design and implementation of a platform suitable for commercial wireless sensor-actuator systems. Battery life and cost have been the most important restrictions in the design, since they can determine the market success of a product. This paper presents the key issues that have been obtained, and how they have been handled, when these restrictions were applied to both hardware and software. In software, they have been considered throughout all the stack, based on IEEE 802.15.4, including some topics that are out of the scope of the standard, such as: the scheduling of the active and inactive cycle of devices and the application data transfer model. This paper also details a novel centralized method of beacon transmission scheduling which avoids overlapping in any case. All the issues presented have allowed to reach a battery life higher than 31 months for sensors and 42 months for actuators.