433 MHz gateway (using RAK831)?

Gateways
1

Hi!
I wanna build 433 MHz gateway using RAK831.
I read here:

And here:

That TTN didnt support 433 mhz back then.

Does it support it now and is it possible to build 433 mhz GW using this HW?
Im choosing a topic for my masters thesis and one of the possible topic is “Build 433 MHz GW and connect one node to it using TTN”.
So Im just checking if this is possible now and if TTN uses 433 MHz (because when I wanna register my GW in TTN v3, it allows me to select 433 frequency plan). Im in Europe.

Do you have any experience with this HW and 433MHz?

2

I believe for a Masters Thesis you need to do the research, not members of the community.

Have you at least read the docs?

3

I havent chosen it yet, teacher said that before choosing I should find out if 433 MHZ on TTN and building 433 GW is even possible.
So im asking so I know whether to choose and its doable. :slight_smile:
EDIT: yes I read that TTN v3 should support it, but in some forum discussions It seemed like it still doesnt…?

4

Check the documentation for supported frequency plans. If it is there there is a chance it is supported. However be aware you will be one of very very few using it because TTN historically uses EU868. I’ve been reading the forum almost daily since 2015 and I can’t remember anyone reporting successfully using it.

5

Did you consider using Chirpstack instead of TTN for your research?

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6

Or a private instance of the things stack, with the goal of fixing any issues needed to get 433 support working.

At the end of the day, it’s in decreasing order of limitation

  1. Regulatory landscape
  2. Hardware availability
  3. Building/improving open source software

But it’s not entirely clear why OP things this is a worthwhile project.

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7

In my opinion, the use of 433 MHZ is beneficial in rural area’s where you need fewer gateways than with 868 MHz because of propagation. In the urban areas, the indoor penetration is better with 433 too.

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8

The disadvantage of 433Mhz is that the band is extremely busy. Multiple users ‘spam’ the band with minutes of continuous transmissions. Years ago I used 433Mhz based gear that went into disconnect alarm multiple times a week because the receiver had been unable to receive any of the transmissions from the transmitter for over an hour.
It would be interesting to know if Lora (and LoRaWAN) suffers less from this kind of band squatting.

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9

In general yes - but depends on the modulation scheme of the interferer - LoRa performs well in the face of OOK, MSK & FSK and other legacy modulation signals gaining some 17-23db headroom (hence also able to receive signals below the noise floor. Also good at avoiding mutual destructive interference which helps with the classic near/far problem. With FSK signal is usually considered to need to be ~8db above interfere for reliable recovery (some argue down to 7 or even 6db but others claim high reliability demands >10db so you take your choice! IIRC at 433Mhz bands also fewer and narrower? leaving less room for interferer avoidance and few operators in the band switch randomly acrossthe available channels but rather squat on one or two or thre and maybe just cycle the few they use.

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