Can not use end device using AS923-2 in The Thing Stack

phitran · November 21, 2022, 12:41pm

Hi Mr. Jeff,
According to Lora Alliance documentation, AS923-2 has a frequency of 920-923. It’s different from that of TTN

Jeff-UK · November 21, 2022, 12:51pm

Indeed, and you saw my comment above wrt Freq offset under plan, and comment wrt reduced number of channels available under the plan…then you looked at the links provided by Jason @jreiss, specifically this one appears to hold - if @Johan comments you might get more…us voluteers dont set the plans unfortunately (or more likely fortunately )

github.com

TheThingsNetwork/lorawan-frequency-plans/blob/master/AS_923_2.yml

band-id: AS_923_2
uplink-channels:
- frequency: 921400000
  min-data-rate: 0
  max-data-rate: 5
  radio: 0
- frequency: 921600000
  min-data-rate: 0
  max-data-rate: 5
  radio: 0
downlink-channels:
- frequency: 921400000
  min-data-rate: 0
  max-data-rate: 5
- frequency: 921600000
  min-data-rate: 0
  max-data-rate: 5
radios:
- enable: true
  chip-type: SX1257

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jreiss · November 21, 2022, 10:17pm

AS923-AS925 (“AS2”) may have been created before AS923-2 existed in Regional Params spec.

AS923-AS925 (“AS2”) == AS923-1
AS923-AS925 (“AS2”) != AS923-2

AS920-AS923 == AS923-2
You say that this plan is working. I would use this plan.

Unless you have more info?

phitran · November 22, 2022, 1:28am

The gateway can get data from the end device but the end device still cannot join the network server. It says “uplink chanel not found” error like the image attached above

jreiss · November 22, 2022, 3:06am

Which plan have you selected for your gateway and end-device in TTN?

Both gw and device settings in TTN must match.

Uplink channel not found usually means the end device record in TTN is not correct.

phitran · November 22, 2022, 3:29am

I selected AS920-AS923 for both gw and end device

kersing · November 22, 2022, 9:28am

Is your device set to OTAA or ABP?

phitran · November 23, 2022, 1:13am

Hi Mr. Kersing,
My end device was set OTAA.

kersing · November 23, 2022, 11:11am

That happens if the device sends data on a frequency that does not match the device settings. Make sure your hardware is configured to use:

otherwise it will not be able to join.

jreiss · November 23, 2022, 8:45pm

AS920-AS923 looks to be another AS923-1 version.
Channels are 922.0-923.4 MHz so the channels your device and gateway are using, 921.4 and 921.6 are not supported.

Asia 920-923 MHz (AS923 Group 2) plans are what you are looking for.
They only support the two default channels as @Jeff-UK has shown.

jreiss · November 23, 2022, 8:48pm

The mapping of TTN UI dropdown selections to plans are shown in this file.

github.com

TheThingsNetwork/lorawan-frequency-plans/blob/master/frequency-plans.yml

- id: EU_863_870
  band-id: EU_863_870
  name: Europe 863-870 MHz (SF12 for RX2)
  description: Default frequency plan for Europe
  base-frequency: 868
  country-codes: [al, ad, ao, at, bh, be, ba, bw, bg, cg, hr, cy, cz, dk, ee, sz, fi, fr, gr, hu, is, ie, it, lv, ls, li, lt, lu, mg, mw, mt, mu, md, me, mz, na, nl, mk, ph, pl, pt, ro, ru, sa, rs, sc, sk, si, za, es, se, ch, tz, tr, ae, gb, va, zm, zw]
  file: EU_863_870.yml

- id: EU_863_870_TTN
  band-id: EU_863_870
  name: Europe 863-870 MHz (SF9 for RX2 - recommended)
  description: TTN Community Network frequency plan for Europe, using SF9 for RX2
  base-frequency: 868
  base-id: EU_863_870
  country-codes: [al, ad, ao, at, bh, be, ba, bw, bg, cg, hr, cy, cz, dk, ee, sz, fi, fr, gr, hu, is, ie, it, lv, ls, li, lt, lu, mg, mw, mt, mu, md, me, mz, na, nl, mk, ph, pl, pt, ro, ru, sa, rs, sc, sk, si, za, es, se, ch, tz, tr, ae, gb, va, zm, zw]
  file: EU_863_870_TTN.yml

- id: EU_863_870_ROAMING_DRAFT
  band-id: EU_863_870
  name: Europe 863-870 MHz, 6 channels for roaming (Draft)

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phitran · November 24, 2022, 12:44am

Yes, I think this is a problem. My end device has been set with AS923-2.The actual frequency it sends to the gateway is 921.4-921.6MHz. This frequency complies with the LoRa Alliance, Inc. specification for AS923-2. But on TNN I can’t find suitable option for AS923-2. The option Asia 920-923 on TNN is AS923-1. Does that mean I can’t use AS923-2 on TTN?

phitran · November 24, 2022, 12:46am

Thanks a lot for your reasonable explanation. Does that mean I can’t use AS923-2 on TTN?

jreiss · November 24, 2022, 1:23am

“Asia 920-923 MHz (AS923 Group 2)” plans are what you are looking for. There are several options.

Group 2 = A923-2

tomtobback · November 25, 2022, 4:03am

Hi @phitran, i’m using TTN in Hong Kong, same frequency plan AS923-925 (“AS2”).
This is my gateway config:

And my end device:
Screenshot from 2022-11-25 11-53-09
I use the LMIC library with #define CFG_as923 1
This works well, and my gateway sees other non-TTN uplinks (923.2-924.6MHz) so i think this configuration is correct.

phitran · November 25, 2022, 9:56am

Hi Mr. @jreiss,
I am using The Things Stack with v3.15.5 and I can’t find the right frequency option. Is there any limitation with this version?

Jeff-UK · November 25, 2022, 10:54am

Currently TTS(CE) (aka TTN V3) running on 3.22.2 so you are somewhat behind wrt maintenance & updates/features/compliance/security etc. and would recommend you update, irrespective of freq plans

phitran · December 5, 2022, 10:47am

Hi Mr. @Jeff-UK ,
Thanks for your advice.I have updated to V3.20.0 version. Selecting AS923-2 has appeared but I am having a similar error in the link below. I have read the comments and have not found the solution yet.

descartes · December 5, 2022, 10:51am

As this is a double post but the other is more relevant, closing this thread.