Enhancing RSSI Technologies in Wireless Sensor Networks by Using Different Frequencies

This paper describes effects of different frequencies on RSSI measurements and proposes how to increase distance measurement accuracy by using these effects as a new method. RSSI values depend on communication frequency and distance between receiver and transmitter. Electromagnetic signals´ free space path loss value is related with their frequency. By using different frequencies, distinct RSSI values can be achieved for the same distance. By comparing these distinct RSSI values, it is possible to increase distance calculation accuracy. Higher accuracy at distance measurement provides more sensitive localization and tracking. Simulations are done at 433MHz, 2.4 GHz and 5.8 GHz and different RSSI values are obtained for the same distance. Furthermore 2 kinds of block diagrams are suggested to generate and receive different frequencies by a single transceiver.