Extra channels setting behavior in as923-1

[zeara]

I apologize for any disturbance.

Recently, I encountered an issue with my deployment of a ChirpStack V4 stack, where I configured the region as AS923-1. I edited the extra channel configuration, and my current AS923 settings are as follows.

[[regions.network.extra_channels]]
frequency = 923600000
min_dr = 0
max_dr = 5

[[regions.network.extra_channels]]
frequency = 923800000
min_dr = 0
max_dr = 5

[[regions.network.extra_channels]]
frequency = 924000000
min_dr = 0
max_dr = 5

[[regions.network.extra_channels]]
frequency = 924200000
min_dr = 0
max_dr = 5

[[regions.network.extra_channels]]
frequency = 924400000
min_dr = 0
max_dr = 5

[[regions.network.extra_channels]]
frequency = 924600000
min_dr = 0
max_dr = 5

I have two different gateways, and I have selected AS923-1 for both gateways. They are located in different places and are receiving data from different End devices. However, I noticed that the channel frequency configurations between the two gateways are not the same, one is from 922.0-923.4, the other is from 923.2-924.6.

i know that Mandatory Channel Freq (Join Req) of AS923-1 are 923.2 and 923.4.

As a result, I can only receive data frames from the frequencies 923.2 to 923.4, while all other frequencies are lost. I know that because my chirpstack only config channel freq from 923.2-924.6.

I attempted to configure the extra channels in ChirpStack to cover the range from 922.0 to 924.6 and restarted ChirpStack. Although I can see the newly added frequencies in the ChirpStack web UI, this has had no effect, as the end devices data from the 923.6 to 924.8 still loss even after being rejoin. I convince that in the end device is on debug mode and update data every 30 seconds(for testing).

I can see the data frames on the gateway, but I can’t see them in the Events tab on ChirpStack. Additionally, the frame counters (FCnt) are not continuous, there are several uplinks missing between two uplink.

My questions are:

1. If I can’t modify the channel frequency configuration of a large number of gateways, can I adjust the extra channels in ChirpStack to support gateways with different channel frequencies?

2. In the case of AS923-1, when encountering the aforementioned situation, can I configure the extra channels to cover all frequencies from 922.0 to 924.6 without causing data loss?

[sp193]

1. When it comes to channel plans, the gateways, LNS and the nodes must share the same understanding of the channels.

Nodes will usually learn of the extra channels from the LNS (unless the channels are preconfigured), but the gateways may not. If the classic UDP Packet Forwarder (or similar) is used, then the channels may be configured inside the gateway (separately from what you select in Chirpstack’s UI). On the other hand, the Semtech BasicStation module will receive the channels from Chirpstack.

If you want to have different channels for different sets of gateways, you will have to create multiple channel plans and the two sets of devices will not share the gateways.

2. You can add any channels you want, as long as you stay within the capabilities of your LoRa Gateway. If you’re using an 8-channel gateway, then you can only have 8 channels.