If a random value generated by this terminal is larger than the predetermined threshold, it keeps "silent" and
retries this packet in the next window.
Since the ZigBee (or rather IEEE 802.15.4) specification allows the use of multiple repetitions (
retries) of the same message in case of reception failure, the effectiveness of this methods has been tested providing both quantitative and qualitative results along with recommendations for a smart application of this technique in order to avoid some consequences impairing the system performance if the
retries are set to excessive values.
According to Echovox, SRE will improve the delivery rate of premium SMS when it intelligently
retries sending messages that experience delivery failure on the first try.