Stability issues with UG67 + 200 sensors on EU868 – frequent missed uplinks and downlinks

Gateways
1

Hi everyone,

We are currently running a network using a Milesight UG67 gateway with approximately 200 LoRaWAN devices (mostly electricity meters) on the EU868 band. Each device sends a downlink approximately once per hour.

Over the past week, we’ve noticed increasing instability:

  • Some devices stop sending uplinks for several hours.
  • In many cases, downlinks are not delivered at all.
  • When registering about 20 new sensors at once, only a few actually join the network. The rest need to be added manually, with at least a 20-second delay between each join attempt.

We are using the latest firmware from Milesight on the UG67, together with ChirpStack v4. The gateway is configured via packet forwarder mode (Semtech UDP).

My questions:

  1. Are there recommended settings for ChirpStack or the gateway to improve stability with a larger number of devices?

I’m happy to provide any additional details you need — such as .toml configuration files, join settings, or gateway logs.

Any help or suggestions would be greatly appreciated.

Thanks in advance!

2

Hi @Wouter_van_Reeven!

Did you enable ADR?

What is the average data rate (DR) used by your sensors?

Also, have you checked the traffic captured by your gateways? If one or several device is spamming the network with continuous DR0 messages, it could cause congestion and lead to data loss or delays for other devices.

Another point to consider would be the network latency.