Design of a low power wireless sensor network for environmental monitoring

[摘要] A WSN (wireless sensor network) consists of a collection of small, low power electronicdevices that can sense their environment and communicate with each other in order tosend data to a base station for logging and monitoring. Research done on WSNs hasincreased rapidly over the past few years, as the necessary RF hardware has becomecheaper and smaller. The wealth of information and hardware available in this field hasmade it possible to design and deploy networks for a multitude of monitoring purposes,on almost any terrain, without an existing telecommunication infrastructure.This thesis presents research into some major aspects of WSNs and the implementation ofa test system with wireless sensor motes, that can be used for environmental monitoring,conservation purposes, impact studies, early warning systems for floods, fires etc. Thesystem also has a wide range of possible uses in agriculture, as more data and bettercontrol over crops can increase yield.The power constraint of sensor nodes is one of the biggest concerns, as batteries canbe depleted quickly and render a system useless. For this reason, work was focused onreducing power consumption of the hardware by means of various methods. Power use wasalso simulated very successfully, giving a accurate way of predicting node lifetime witha variety of battery types. The system was implemented on the Tmote Sky hardwareplatform using the open source sensor network operating system, TinyOS.

[发布机构] Stellenbosch University