Adding an 868mhz gateway in NZ

Hello Forum, long story short I ended up designing and paying for 20 sensors to be built using radios RFM95W-868. This was before I realised NZ was designated to use 915 as per the LoRaWAN Alliance. So I can use these sensors can I add a 868 gateway to TTN in NZ, is this ok?

My next batch of sensors will be using radios compatible with AS915.

Cheers
Paul

Hi,
not the Lora Alliance assigned the 915 Mhz to NZ, it is based on local laws which based on the frequency setting of the ITU (International Telecommunications Union).

868Mhz is defined in New Zealand as “864 - 868.1 MHz Cordless Telephone ‘CT2’ Band”, so it is only free for cordless telephones,
915 - 921 MHz is designated by the ITU and local law for “General User Radio Licence for Short Range Devices”

Found here: https://www.rsm.govt.nz

regards
Stefan

Hi Biermi, there’s a local LoRa provider operating at 868, they were the first to offer LoRaWAN in NZ ( I believe).

They say on their web site they have aligned themselves with the EU and Indian frequencies.
868 is a free spectrum in NZ which may have been set aside for cordless phones but probably used for many more reasons.

Cheers
Paul

Hi fellow Kiwis,

As far as what is allowed in NZ, my reading of the ‘General User Radio Licence for Short Range Devices’ is that we have every one of the Things Network frequency plans available to us apart from US902-928 and CN470-510/CN779-787 plans.

This leaves us with the difficulty of choosing one (at least I’ve had this difficulty). While the easiest to set up is EU868, due to hardware and library support, but… it is hugely limited by Max EIRP (3dBm) and duty cycle.

IMHO this leaves three choices:

  • AS923 - EIRP (36dBm)
  • AU915 - EIRP (30dBm)
  • IN865 - EIRP (36dBm)

AS923 is by far the best choice in terms of max EIRP and bandwidth available (it is the choice of Spark NZ’s LoraWAN network) for NZ. But… hardware for AS923 isn’t readily available. And (this goes for all of my three choices above) Arduino library support for these frequency plans is poor. And while NZ’s radio licensing is not limited to a 400ms dwell time the AS923 standard is. Meaning that any library or hardware made for AS923 use a 400ms dwell time and the other regulations/limitations of the AS923 plan - default max EIRP of 16dBm.

AU915 is slightly better in that it isn’t limited by 400ms dwell time or limited max EIRP (30dBm). But like most Kiwi blokes think, “Who would choose 30dBm, when you could choose 36dBm?” And apparently many of the Aussies on this forum think the same way as there seems to be a lot that use AS923. Or maybe there’s another reason?

That leaves IN865. The issue I see with this plan is that it seems unfinished; there are only 3 channels, but there aren’t any real limitations on use (duty, dwell time, etc). And there is limited bandwidth available - 864-868MHz - compared to the other plans above. This is also (roughly) the plan chosen by KotahiNet, currently NZ’s largest established LoraWAN network.

As the Lora Alliance has chosen AS923 for NZ it is the obvious best choice for anyone setting up a big install - like Spark NZ/Chorus/Kordia networks - and should be the default plan for NZ on TTN. But for small players and people who want to play with TTN and making their own nodes, my current conclusion is IN865 is the best choice. Mainly because we can readily get hardware that is suitable - (EU)868 hardware is close enough to the right frequency, and by far the easiest to find from China. When AS923 hardware becomes readily available it will become the best choice.

(For people using Arduino IDE I would highly recommend this version of LMIC that has regional support for regions other than EU868 and US915)

P.S. I am very new to Lora and Things (2 months), so am very interested in being corrected where needed…

Hi Chaolue, thanks for your great summary. We are using the LMIC library in our sensors which contain the ATMEG328P MCU and RFM95W-868 radio. We didn’t originally plan to use LoRaWAN, it was going to be a P2P network with our own gateways on Raspberry pi’s but changed recently, and glad we did. My target is rural monitoring so options for commercial LoRa coverage is limited so using a gateway and TTN is a great option.