PiBox » Iron Man

In order to save power for IoT devices, the ESP8266 should be placed into the lowest possible power state where it can be awakened by network access. In order for this to work, the receive side of the modem (at least) must remain powered and active. The MAC will need to be powered and clocked. It will ultimately be the MAC that wakes the rest of the microcontroller. From the datasheet, page 18, it appears that this is the "SLEEP" state, which is not the lowest power state but current consumption should be < 1mA, according to http://bbs.espressif.com/viewtopic.php?t=133 and the datasheet.

The datasheet page 8 says: "ESP8266 consumes less than 12uA in sleep mode and less than 1.0mW (DTIM=3) or less than 0.5mW (DTIM=10) to stay connected to the access point." That would appear to indicate that we can power it down to DTIM10 while maintaining wifi connectivity. Whether or not it will detect being addressed at that level remains to be seen.