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LoRa Radio Module - 433MHz - legal?

I am looking at building a wireless Modbus data link and am firstly trying to determine the RF side of it. The LoRa Radio Module - 433MHz will do the trick but my concern is about the legalities. Even if the power is reduced to the maximum required by ACMA for this band, does that make this legal? Unfortunately I can’t get this question answered but perhaps I’ve mistakenly assumed that because it’s being sold in Australia it complies. Any advice is appreciated. Thanks

Hey Greg,

I’ve been trying to wrap my head around LoRa for a few weeks now. This is my general understanding:

  • Are LoRa devices legal in Australia? Yes, when configured for the AU915 region. Specifically, use of other region configurations (EU868, US915, etc) are not legal.
  • Are LoRa 433MHz devices legal in Australia? It seems so (ACMA: Spectrum at 434 MHz for low powered devices)

The main issue with LoRa (and Sigfox) is that they’re operated under a “golden rule”. That rule is that each device can transmit for no more than 1% of the time. The reason is that all devices using the ISM radio band are sharing limited spectrum and need to share with thousands of other devices that might be in range (range > 10km). Messages must also be tiny: only a few bytes.

That said, LoRa radios can be used in FSK mode to talk point-to-point and as I understand it, FSK mode falls outside “the golden rule”. Certainly, if you’re using LoRa modulation (chirp, not FSK) you need to obey the golden rule. So I would think you’re after LoRa.FSK.

Does that help at all? Apologies I can’t point to a black-and-white answer.

  • Chris

Hi Chris

Thanks for your reply. Don’t apologise for not having a black-and-white answer, the more I look into it the greyer it appears as you have found.

The ACMA link appears to allow such things if EIRP is under 25mW, but others have told me that unless a device has a specific approval it still can’t be used.

Thanks for your comments re FSK - I’ll look into this further.

Greg

Hi again

Another possibility here that might give me the range required is the 2.4GHz band. Again, no licensing and it’s treated as a ‘public park’ by ACMA, subject to certain restrictions.

I was staying away from this frequency and don’t want to use WiFi, but my thought is that there are Zigbee devices with RS-485 interfaces that could work. Is there any experience with these vs LoRa for a simple transceiver need such as mine.

Greg

Many radios are approved to this standard:

https://incompliancemag.com/article/the-eus-new-radio-equipment-directive-red-201453eu/
Not sure IF this integrates with ACMA requirements.
AS 4268 is also part of the approval process.

Cheers,

Jack

The 433.05 to 434.79 MHz band is a very limited band and not suitable for LoRaWAN in AU.
Although, you could fit 3 x 500 kHz [DataRate 6, 8-13] (or 6 x 125 kHz [DR 0-5]) Bandwidth “channels” in RAW-LoRa mode (such as peer-to-peer mode).

AFAIK, the 1% Duty Cycle does not apply in AU (according to the LoRaWAN Regional Parameters v1.0.2rB)!

For digital modulation transmitters (915-928 MHz), max. EIRP is 1 W, but
“1. The radiated peak power spectral density in any 3 kHz is limited to 25 mW per 3 kHz.
2. The minimum 6 dB bandwidth must be at least 500 kHz.”

For hopping (min. 20 hopping frequencies) transmitters (915-928 MHz), max. EIRP is 1 W.

AFAIK, LoRaWAN does not utilise 20 hopping frequencies, so the restrictions for “digital modulation transmitters” must be observed!

As the minimum 6 dB bandwidth must be at least 500 kHz; does that mean that we can use ONLY DR 6, 8-13 for LoRaWAN?

Hi Peter,

The TTN forum has a lot more activity in this space and there are some conversations that shed light on how to work within ACMA’s changing landscape. Here’s another (touches on the current debate on AU915 and AS923 and ACMA compliance)

From what I’ve seen over the years, ACMA has been industry-centric and have a net-positive approach with supporting new technologies. There are lots (lots!) of discussions around IoT / LoRaWAN / others and it’ll be interesting to see how the regs change over time to balance spectrum use. For example, for LoRaWAN I’d really like to see a lockdown on either AU915 or AS923, having so much as two options halves the interoperability of a lot of effort.

Thanks Graham,
Limitation 2. "The minimum 6 dB bandwidth must be at least 500 kHz ” is no longer in place (at least since 27 June 2018, F2018C00500). My mistake!

What do you mean by “for LoRaWAN I’d really like to see a lockdown on either AU915 or AS923, having so much as two options”? I don’t believe AS923 is an option for AU. It is for:
Brunei [923-925 MHz] 1007
Cambodia [923-925 MHz] 1008
Indonesia [923-925 MHz] 1009
Japan [920-928 MHz] 1010
Laos [923-925 MHz] 1011
New Zealand [915-928 MHz] 1012
Singapore [920-925 MHz] 1013
Taiwan [922-928 MHz] 1014
Thailand [920-925 MHz] 1015
Vietnam [920-925 MHz]
, but do agree it is silly that NZ has to be different!

I’m curios to see if anyone has any current references to Duty Cycle restrictions in AU915.

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Hi Peter,

The majority of Australia is using AS923 for The Things Network. The AU915 is bespoke (from a global product-design perspective) and that ripples into less options for hardware choices. It’d be nice if it were just one or the other. I’d lean to AS923 for simplicity sake and the higher likelihood of new product support from IoT vendors.

Wow! I was not aware of that, as I have only been building Private commercial LoRa systems (for about 18 months now). I never considered using a different channel plan (and probably won’t for commercial purposes)!