Study on the communication link quality in wireless sensor network

Firstly, the hardware and software platform is established to demonstrate our system´s basic functions with the protocol IEEE 802.15.4. Hardware design about gateway and nodes are described briefly. Secondly, when our demonstration system works, received signal strength (RSSI) and correlation value of symbols of the received packet (CORR) can been obtained from the chip CC2420, the relationship of which is researched under the different received packet rate circumstances. The curve figure shows the special relation and theoretic limited values. In the end, the linear relation between RSSI and LQI is calculated. Utilizing it, these two values can been converted each other.