EU433 configuration

[temporaryaccount]

There is no configuration file for a gateway with SX1255 transceivers using 433MHz channels. Can anybody provide me a working configuration file? Thanks.

[htdvisser]

Maybe @tftelkamp already has something in mind, but otherwise please make a proposal. The minimal channels are 433.175 433.375 433.575, then we'd have to come up with the extra 5 channels.

[temporaryaccount]

Maybe these pieces of code (band_eu433.go, RegionEU433.c, RegionEU433.h) can provide some reference material, for example this function has the minimum and maximum frequencies:

static bool VerifyTxFreq( uint32_t freq )
{
    // Check radio driver support
    if( Radio.CheckRfFrequency( freq ) == false )
    {
        return false;
    }

    if( ( freq < 433175000 ) || ( freq > 434665000 ) )
    {
        return false;
    }
    return true;
}

This manual about setting up a 433MHz gateway has a configuration sample and as long as I can decipher it they offer to use these frequencies: 434.1, 434.3, 434.5, 434.7, 433.3, 433.5, 433.7, 433.9 at 125kHz (chan_multiSF_xxx), and 434.2 at 250kHz (chan_Lora_std) which is strange because they overlap and also the required 433.175 433.375 433.575 channels are missing.

By the way, what is the difference between chan_multiSF_xxx and chan_Lora_std?

Added later:
LoRaWAN Specification, section 7.4 EU 433MHz ISM Band.

[htdvisser]

what is the difference between chan_multiSF_xxx and chan_Lora_std?

The chan_multiSF_xxx configures a 125kHz channel that demodulates all LoRa spreading factors. The chan_Lora_std usually configures a 250kHz channel that demodulates a fixed LoRa spreading factor. Then the chan_FSK configures a channel that demodulates FSK. A "full" config file configures 8 multiSF LoRa channels, one std LoRa channel and one FSK channel.

[temporaryaccount]

I couldn't find any official documentation about the additional channels for EU433, so I'm trying to allocate the frequencies by myself. I have two questions though:

1. When we define a channel, for example 433.175 with 125kHz bandwidth, is it the "left" frequency or the "central frequency"? In other words, does it mean the channel will occupy the 433.175-433.300 frequencies, or the 433.1125-433.2375 frequencies?

2. We can see in EU-global_conf.json that both chan_Lora_std (250kHz) and chan_multiSF_1 (125kHz) are using the same 868.3MHz channel, how is it possible? Is it because they are using different spreading factors so they can use the same frequencies?

Thank you.

[johanstokking]

@temporaryaccount

1. Center frequency
2. I think so yes cc @tftelkamp

[jpmeijers]

TODO:

• Inventorise the 433MHz ISM/license free/SDR bands across the world.
• Using the proposed EU433 channels, try and find as many overlapping channels as possible.

Because 433MHz is quite a standard ISM band internationally, this is the ideal band to try and find at least one standard channel that will work everywhere. If a device joins on that channel(s), they are guaranteed to be heard as long as there is a 433MHz gateway in range.

[YarovoySergey]

https://net868.ru/assets/pdf/LoRaWAN-Regional-Parameters-v1.1rA.PDF