1) How is the timestamp in the receive descriptor (rs_tstamp) defined? Is it the first 15 bits of the TSF at the time of reception of a) the first PHY symbol, b) the first data byte, c) the first bit of the 24th data byte where the timestamp field of beacons and probe response frames is usually found, or d) something else?

2) Is RSSI relative to a fixed reference point or to the last noise floor calibration? In that case, is it equal to the signal-to-noise-ratio (SNR)?