A Practical RF Propagation Model for Wireless Network Sensors

In the present work, we propose a practical RF propagation model - free-space outdoor model - suitable for WSN due to the fact that it considers the most important WSN constraints and RF signal propagation path loss factors. The model is based on combining four path loss factors, which cause distortion and weakening of the RF signal, i.e. free-space path loss, ground reflection path loss, RSS uncertainty and antenna pattern irregularity. The proposed model is verified with actual measurements realized with Tmote Sky sensor node equipped with 2.4 GHz CC2420 radio module.