Frequency plan adjustment, AS2->AS1

Heath Raftery

Head of Technology at NewieVentures

Posted on 07-12-2018

At the outset of this community we adopted the AS923_925 ("AS2") frequency plan in an attempt to harmonise with the rest of the country. In the meantime the national recommendation has been refined to the AS1 variation of AS923, also known as AS920_923.

To maximise interoperability of devices and know-how, we will also adopt AS1 going forward. That's going to mean a bit of transition pain now for future gain.

Because AS1 and AS2 are just variations of AS923, with some overlap, this is a relatively easy transition. Here are some notes from Andrew Maggio at Meshed:

Gateways

Change to AS920-923 on the TTN Console Gateway page, then depending on packet forwarder:

  • mp-pkt-fwd & poly-pkt-fwd: Rerun installer.sh, accept all defaults
  • Multitech lora-packet-forwarder: Change “Additional Channels” field
  • resin.io based gateways: Can’t remember exactly, but I think it’s just a single field change and a redeploy
  • basic-packet-forwarder: Update global_conf.json with https://raw.githubusercontent.com/TheThingsNetwork/gateway-conf/master/AS1-global_conf.json

Nodes

End devices will fall into one of these categories:

  • Uses Link Check or Periodic join and rejoins the network on its own to receive updated channel plan (nearly all devices we sell fall into this category)
  • Is able to receive and process NewChannelReq MAC command, which we could send to devices to update their channels. I’m not entirely sure how we would do this but I believe it’s possible.
  • Is hardcoded to specific frequencies and is unable to change. These devices (which are not LoRaWAN compliant) will need to be changed manually.