This paper describes a system design approach for a wireless sensor network based application that is to be used to measure temperature and humidity as well as being fitted with a smoke detector. Such a device can be used as an early warning fire detection system in the area of a bush fire or endangered public infrastructure. Once the system has being develop, a mesh net work topology will be implemented with the chosen microchip technology with the aim of developing a sophisticated mesh network. This paper fully describes the domain problem as well giving an over all system design description, with a software simulation technique which will be used to demonstrate how data will rotate from one node or sensor to the other.