Receiving data from multiple gateways

ChirpStack Network Server
1

Hii,
I have 2 lora gateway configured with 2 different MAC id connected to our custom platform.
I configured all the gateways in loraserver in order to get stats of each gateway.
I have one OTAA class A node, I confirmed that both the gateways receiving data from OTAA node, but our application is receiving data exactly once from lora app server, eventhough both the gateways are receiving data.
Is loraserver is handling the duplication of data receiving from multiple gateways ?
We are using latest version of LoRa Server binaries

2

Yes, the Network Server handles the de-duplication and combines the data from multiple gateways into one payload which is delivered to the Application Server.

1 Like
3

Thank you brocaar for your immediate reply. kindly close this topic

4

Hello There,
I’m using too, multiple gateway . and i have some sensor in the “cover range” of both the two gateway.
at the begining i see the RSSI pass from one to another and i said greaat it working well and all is combine to make a unique payload message. but today i see some problems

After few days of use. i get one sensor wich have initiated over 700 “join” to the network. As if each time it switch gateway it start a new join session.

First impact, it totally flood the table device_join . could i delete all the useless field ?
second and more important problem : after move the sensor from one place to another this one try to reconnect with the error: “validate dev-nonce error”

I suppose there is a link between the fact that the sensor use to much join session and the dev-nonce error . right???

5

Hi Kaptepatou,

It depends on which LoRaWAN spec version your sensor follows. The DevNonce should be a unique value for each join attempt. Can you confirm your sensor uses a new value for every Join attempt? You can see this in the MacPayload message in the Join-request message in the Applications --> LoRaWAN frames view. If you configured LoRaWAN spec 1.0.2 to be used by your Chirpstack Server, there are only 65535 values available for this DevNonce and you might have run out? Try flushing the DevNonce table for this device (or just remove it and add it again) and see if this resolves your issue.

Best regards,
Pieter

1 Like
6

Further question for this topic. Is it safe to assume that the first gateway in the rxInfo was the first one received by mqtt/network server ?

thanks.

7

No, please do not assume any ordering.

1 Like
8

Hi brocaar. First of all i’d like to congratulate you on the great project that chirpstack is. I have a similar question for this topic.

I have a project that is using 4 gateways dispersed in a mall building, and several water meters connected. When monitoring the meters, i noticed that they keep sending payloads from different gateways (i.e. a meter that sends 3 payloads per day, sent its payloads from 3 different gateways).

According to your answer above, the network server handles the de-duplication and creates a combined payload. My question is, is the gateway reported by the application server, the actual one the meter used to send the payload, or is it a bit arbitrary in the sense that it picks the last one or something ?

To elaborate, i want to make sure that the planning that was done for the building (where the gateways were placed) is the best possible, and to do that i need to know which gateways are used the most and which ones are placed in a way that won’t serve the purposes of the project.

Thanks!

9

Yes, the ChirpStack Application server exposes all receiving gateways.