Part Number: WL1835MODCOM8B
Other Parts Discussed in Thread: WL1835MOD, WL18XXCOM82SDMMC
Hello,
My customers evaluate the performance of WL1835MODCOM8B with RTTT and latest firmware (R8.7_SP3).
And they complain that some performance doesn't meet the standard of IEEE 802.11.
For example, the ramp-up of 802.11b and the flatness of 802.11j look not to meet the standard.
Please let me know how to adjust these performances in .INI file or other settings.
Best Regards,
Nomo
Hello Eyal-san,
Thank you for your reply.
They use the attached INI file and the attached waves are captured.
The first figure shows the 11g flatness result (17dBm output) and the second figure shows the 11b ramp power (16dBm output).
Could you evaluate WL1835MODCOM8B with the same settings and attach the results?
https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/968/2055.WL1835MOD_5F00_INI.ini
Best Regards,
Nomo
Hello Eyal-san,
Thank you for your reply.
However, the results don't improve.
I have just one question.
Does WL1835MODCOM8B meet the standard of IEEE 802.11b and IEEE 802.11g?
If yes, please let me know the procedure to meet the standard.
The followings are the results.
My customers use WL1835MODCOM8B and WL18XXCOM82SDMMC.
Power is supplied to WL1835MODCOM8B via USB and WL1835MODCOM8B is controlled with RTTT.
(In case the power is supplied from external 3.3V, the results are the same.)
The firmware and INI file is the latest ones which is available from the following web site.
git.ti.com/.../R8.7_SP3
git.ti.com/.../R8.7_SP3
WL1835MOD_INI.ini and WL1835MOD_INI_C2PC.ini are used as the input INI file.
The results are attached.
The first figure is 11b power ramp with WL1835MOD_INI.ini.
The second figure is 11b power ramp with WL1835MOD_INI_C2PC.ini.
The third figure is 11g flatness with WL1835MOD_INI.ini.
The fourth figure is 11g flatness with WL1835MOD_INI_C2PC.ini.
Best Regards,
Nomo
Hi Nomo-san
Please see below the feedback I got from our hardware experts:
For 11g, they check the flatness with old flatness mask.
In 2016 the flatness spec became more relaxed. It became +4/-6dB, and not +/-4dB, as they test with.
We set the system to the new standard:
As for the 11b – there is a spec about ramp up time (see below).
We tested it once, and saw we meet it.
Please note that this 2us requirement for 11b power-on ramp is really unnecessary considering the long 11b preamble. It does not improve the packet reception and there is no good justification for it. Still, since it is part of the spec than we tend to follow it with a very slight margin.
Looking at the customer’s image, I see he starts counting the 2us long before the 10% power ramp and even before beginning of the packet…this is not according to spec definition.
In other words, the red lines (thresholds) are not placed correctly.
Best Regards,
Eyal
