Power Gain and Sensitivity

When configuring a node and a network, one important parameter is related with power gain and sensitivity.

Power Level

The setPowerLevel() function permits to set the power level at which the device transmits conducted power. The parameter range: from 0 to 4. Default value is 4.

Setting	Power Level (boost mode disabled)
0	5 dBm 1
1	-1 dBm
2	+1 dBm
3	+3 dBm
4	+5 dBm

The boost mode improves the receive sensitivity by 2 dB and increase the transmit power by 3 dB. By default boost mode is enabled.

The setPowerMode() function allows user to set the power mode (boost mode). The parameter values are: 0 (boost disabled) or 1 (boost enabled).

Example of use

{
    xbeeZB.setPowerLevel(0); // Set Power Output Level to the minimum value
    xbeeZB.getPowerLevel(); // Get Power Output Level
    xbeeZB.setPowerMode(0); // Disable boost mode
    xbeeZB.getPowerMode(); // Get power mode
}

Related variables:

xbeeZB.powerLevel → stores the power output level selected

xbeeZB.powerMode → stores the power output level selected

• Power Level configuration example:

https://development.libelium.com/waspmote/zb-14-setread-power-level

Received Signal Strength Indicator

It reports the Received Signal Strength of the last received RF data packet. It only indicates the signal strength of the last hop, so it does not provide an accurate quality measurement of a multihop link.

Example of use

{
    xbeeZB.getRSSI();
}

Related variables:

xbeeZB.valueRSSI → stores the RSSI of the last received packet

The ideal working mode is getting maximum coverage with the minimum power level. Thereby, a compromise between power level and coverage appears. Each application scenario will need some tests to find the best combination of both parameters.

• Getting RSSI example:

https://development.libelium.com/waspmote/zb-06-get-rssi