meshtastic / firmware

Meshtastic device firmware
https://meshtastic.org
GNU General Public License v3.0
3.49k stars 863 forks source link

[Bug]: EU 433 channels centers incorrect #3371

Open audriusb opened 7 months ago

audriusb commented 7 months ago

Category

Other

Hardware

Not Applicable

Firmware Version

2.2.24

Description

Accorting to lora alliance the band plan starts at 433.05Mhz. Not 433.00. It ends at 434.79. The very first channel used by meshtastic is centered at 433.125, but it should be 433.175. ETSI has defined 433 to 434 MHz frequency band for LoRa application. It uses 433.175 MHz, 433.375 MHz and 433.575 MHz frequency channels. Having a bandwidth of 250 kHz makes it out of band and illegal to be used without a licence. Please consider shifting all the channels. IMG_20240311_131545_169

Relevant log output

No response

caveman99 commented 7 months ago

While your observation is technically correct, we can not change the channel raster with a minor firmware version. If we change it at all this needs to go into the next major revision.

Also please take into consideration the ISM band 433.05-434.79 MHz is only a secondarly allocation, primary user being the HAM radio service from 430-439,1 MHz. (and RX only from 439.1-440 MHz) - The borders of the ISM band are crafted with a safeguard gap to prevent carrier overlap outside of 433-435 MHz with broadband signals not to interfere with the allocation of the adjacent frequencies, especially in the sensitive 435-438 MHz Satcom band. So a center frequency of 433.125 and BW 250 kHz will stay clear of 433.000 and this is fine with the primary user of those frequencies.

audriusb commented 7 months ago

I can see there was a discussion about it few years ago https://meshtastic.discourse.group/t/etsi-violations/2719/18

andrekir commented 7 months ago

this is planned for the next breaking cycle in #2696