Hi Morse Micro team,
The maximum TX power of MM8108-EKH19 as mentioned in the datasheet is 26dBm
But when we check it via the webGUI it is limited to 22dBm.
I even tried to increase the TX power using “iw wlan0 set txpower fixed 2600”, but it is also limited to 22dBm.
Thanks,
Arti
Hi Arti,
26dBm is the maximum rating for the TX power of the chip itself.
In actual applications it’s got a few layers of constraints, firstly the SEM and EVM requirements of the 802.11ah, followed by the spectral requirements from your region’s regulatory body. The MCS has a role in determining the former two. There’s also insertion losses when you’re measuring externally.
Hi @michael.mccandless ,
Thank you for your input on this.
We are using MCS 2 with 2 Mhz bandwidth.
We are measuring the data from the GUI.
Which BCF file should we use to get the maximum power?
The BCF which will give you “maximum power” is the BCF that is right for your module, anything else is more than likely going to negatively impact your radio performance.
If you’re manually selecting a BCF, use the BCF that is named to match your module - eg bcf_mf15457.bin.
The bcf_boardtype_<id>.bin are usually installed as symbolic links to specific module BCFs to allow the driver to query the chip to determine which module it must load - as programmed by the module manufacturer.
I missed this bit. For an accurate confirmation of the power levels I would strongly recommend measuring the power with at least a spectrum analyzer or power meter. The value reported here is indicative, and can’t account for per-mcs configuration values. I left some detail in this post: Linux TX Power Max Reported Value for MM8108 - #2 by ajudge
