Packet Error Rate (PER)

V3 of ADR is not based on the device’s radio conditions, but on its PER, or Packet Error Rate. When configuring the algorithm, a target value is set for PER, i.e. for the percentage of UL packets lost in relation to those received that is acceptable. The algorithm calculates the PER for a log of UL frames received and compares the result with the target value: if the calculated PER is higher than the target PER, a “Boost” algorithm is triggered to increase the TX Power, the number of transmissions or the SF, to bring the PER below the threshold; conversely, if the calculated value is significantly below the target PER (new threshold defined with an additional hysteresis to be achieved), then a “Battery_Optim” algorithm is triggered which can reduce the number of transmissions or the device’s SF or TX Power.