Hi Sirs, From wireshark, I noticed that when send an data frame , the duration of frame control is fixed at 60 , no matter the frame length is 100 bytes or 1000 bytes. It seems this value is calculated in firmware and should be correct. But I don't know why. And this value can be set in mac80211? Thanks in advance! Li gang -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html