Hi MartinL,
thank you very much for your reply.
Our project is about the implementation of a data transceiver using arduino zero.
Both the input and output of Arduino are serial messages, all my arduino zero is doing is reading serial messages, doing basic software filtering, and sending serial messages (using print command) through another serial port.
The arduino zero will be powered by battery. At the moment, the board is running full time at full power. However, the input only occurs at the first 5-10 minutes at each hour. I have implemented a basic interrupt routine to listen to the serial port, and wake up my Arduino Zero.
Unfortunately, as already mentioned in the original post, using the library provided by rocketscream didn't help much. The current drawn dropped only a few mA.