In the Mediterranean area, the wildfire is a very important and critical problem. Environmental monitoring by using of sensors network seems to be a significant alternative of current detection techniques. Wireless sensor networks have been recognized as one of the most important technologies for this Century. Wireless sensor network represents a real and adapted solution to this problem. Test showed the sensor capacity to transmit the data wildfire in real time. However, we don't know if this capacity is reliable with a large number of nodes. We introduce the DEVS discrete event formalism, and to apply it to the modelling and simulation of a great sensor network. The improvement of routing protocol and data transmission quality in the wildfire phenomenon is the base of our research.