Mobility & Robotics
Strong Signal, Weak Connection
A manufacturer of autonomous cleaning robots had the network selection of its devices analysed in the field. It learned why a strong signal does not automatically mean a good connection.
Project / Client
A manufacturer of professional autonomous cleaning robots relies on devices with built-in cellular modems for worldwide use.
The Situation
The robots were supposed to log on to the best available cellular network worldwide on their own. This did not work reliably. Some devices connected to networks outside the intended roaming partners. Connection quality was poor even though reception looked strong, and establishing a connection took a long time.
The client could not find the cause internally. It lay two levels below the application: in the modem’s network selection logic and in the SIM card’s settings.
The Key Question
Why does a device with apparently good reception still establish a poor connection – and where in the technology can this be fixed?
This was not a question that could be answered at application level. It lay in the cellular layer, which normally nobody in the product is responsible for.
What We Built
IOX analysed how the devices select their cellular network – without changing any hardware or software at the client.
The devices decided based on RSSI, a metric from the 2G and 3G era. It only measures how strong a signal is, not how good the connection is. On top of that, there was a fixed network list on the SIM that the device worked through rigidly.
IOX recommended three steps: switch network selection to modern LTE metrics, bypass the fixed list and block unreliable roaming partners.
The Result
The client received a feasible roadmap. All three recommendations can be implemented via firmware and configuration; no new hardware is needed.
Troubleshooting in the field has become easier. Instead of guesses, the client now has a clear explanation of why devices are poorly connected despite good reception.
The cause lay in a layer that nobody in the company was responsible for.