Wireless communications are becoming more and more important in our world. Wireless communication is an alternative to wire communications, often more expensive to deploy due to the extensive number of cables. In some location, it is simply not possible to deploy cables and wireless communications come up handy reducing by far the expenses. We can also see the part of wireless communications in our day to day life, from cellular phone, to computer wifi and even headphones. One of the other ways to use wireless communications is through sensor networks. Sensors are small devices with small transmission range and low energy consumption. Sensors can be used in environmental monitoring, for example to monitor temperature in a forest and, this way, prevent the apparition of fires. The standard protocol 802.15.4 defines a physical layer and a MAC layer which are well suited to be used in sensor network such as LR-WPAN (Low Rate Wireless Personal Area Network). This project will focus on the simulation of a sensor network using 802.15.4 protocol deployed on train wheels. Those sensors would be able to retrieve information as temperature or vibration values and transmit them to a more powerful computer able to treat that information. First of all, I will rapidly describe some simulators which could be used to perform the simulation. By the study of some characteristics, a choice will be drawn. Then, to ensure the reliability of the simulator, a set of tests will be conducted and the results obtained will be compared to theoretical ones. Finally, the last part will deal with the simulation of the sensor network on the train. I will explain the protocol itself and then perform some tests of energy consumption and throughput