See here, top of page 4;
http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps10047/data_sheet_c78-501860.pdf
14dBm = 25mW
17dBm = 50mW
20dBm = 100mW
23dBm = 200mW
Transmit power @ normal temp range for FCC:
802.11b: 16 dBm @ 1TX, 19 dBm @ 2TX, 20.5 dBm @ 3TX
802.11g: 13 dBm @ 1TX, 16 dBm @ 2TX, 17.5 dBm @ 3TX
802.11n: 17 dBm @ 1TX @ MCS0~5/8~13, 13 dBm @ 1TX @
MCS6/14,
11 dBm @ 1TX @ MCS7/15, 20 dBm @ 2TX@MCS0~5/8~13,
16 dBm @ 2TX @ MCS6/14, 14 dBm @ 2TX @ MCS7/15,
21.5 dBm @ 3TX@MCS0~5/8~13, 17.5 dBm @ 3TX @ MCS6/1
4,
15.5 dBm @ 3TX @ MCS7/15
Transmit power @ normal temp range for ETSI:
11b/g/n: 13 dBm @ 1TX, 16 dBm @ 2TX, 17.5 dBm @ 3TX