Comparative Performance Analysis of Wireless RSSI in Wireless Sensor Networks Motes in Tropical Mixed-crop Precision Farm

To provide reliable and adequate network coverage whilst minimizing the cost of wireless sensor network (WSN) deployments, detailed knowledge of wireless signal propagation within the specific environments is required. There are many WSN devices on the market that have been developed using proprietary systems and therefore have different performances, although implementing similar standards. This paper presents a comparative performance measurement and analysis of three types of WSN devices evaluated for application in a mixed-crop farm. The results show that the Xbee-PRO maintains very strong RSSI values in open field measurements that are sometime 15 dBm higher than those obtained from the IRIS and Microchip motes. Overall, two important factors that influence WSN node performances are antenna height and the type of antenna used. Whip omni-directional antenna has been shown to double the range of the WSN node compared to a patch antenna. Results also show that the log-distance propagation model is a more flexible model that can be used to model a variety of channels, although it lacks standard global parameter values.