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Hello,
In the EU, the limit is 20 dbm for the transmit power. In our tests, we observed that our module exceeds 20 dbm in the modulation although in g and n there is no problem about the limit with the default tx power. During the tests, we used mfg_test app with the default tx power by typing the command "txpwr1 -1" over the wl tool.
If we set tx power to <15 dbm (e.g., "txpwr1 -d 14") in the modulation b, measured power is acceptable.
So, in our application on the top of WICED SDK, we need to set tx power for 802.11b to meet the regulation and I do not prefer to reduce transmit power in modulation g and modulation n.
Does WICED SDK have a method to change the transmit power for only modulation 802.11b?
I know the method wiced_set_transmit_power. If I use this method, tx power is decreased for all modulation types.
Thanks for your helps,
Solved! Go to Solution.
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You need to modify the nvram file.
11b power is set in qdbm units by the maxp2ga0 line. eg: maxp2ga0=68 sets +17dBm 11b output power. Whether this matches what you see externally will vary (especially radiated), but you can adjust it relative, eg if you want 1dB lower use (68-4)=64.
The 11g powers are set relative to this, as 0.5dB backoffs per modulation, one nibble per modulation.
eg: ofdm2gpo=0x44444444
means all OFDM modulations are backed off 2dB (MSB = fastest, ie 54Mbps, LSB = slowest, ie 6Mbps)
The 11n powers are set in two 16-bit values, but the concept is the same.
eg:
mcs2gpo0=0x4444
mcs2gpo1=0x6444
means 65Mbps is backed off 3dB, the others 2dB.
So to decrease 11b by 1dB but not alter the 11g/11n powers you would use (in this example):
maxp2ga0=64
ofdm2gpo=0x22222222
mcs2gpo0=0x2222
mcs2gpo1=0x4222
(ie, overall power down 1dB, all backoffs reduced by 1dB)
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You need to modify the nvram file.
11b power is set in qdbm units by the maxp2ga0 line. eg: maxp2ga0=68 sets +17dBm 11b output power. Whether this matches what you see externally will vary (especially radiated), but you can adjust it relative, eg if you want 1dB lower use (68-4)=64.
The 11g powers are set relative to this, as 0.5dB backoffs per modulation, one nibble per modulation.
eg: ofdm2gpo=0x44444444
means all OFDM modulations are backed off 2dB (MSB = fastest, ie 54Mbps, LSB = slowest, ie 6Mbps)
The 11n powers are set in two 16-bit values, but the concept is the same.
eg:
mcs2gpo0=0x4444
mcs2gpo1=0x6444
means 65Mbps is backed off 3dB, the others 2dB.
So to decrease 11b by 1dB but not alter the 11g/11n powers you would use (in this example):
maxp2ga0=64
ofdm2gpo=0x22222222
mcs2gpo0=0x2222
mcs2gpo1=0x4222
(ie, overall power down 1dB, all backoffs reduced by 1dB)
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Hello,
does this answer your question? Let us know if it works.
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Hello,
Thank you very much for your response. Our problem seems to be solved by this new nvram file.