Question:
I'm frustrated by some of the missing updates from my Oyster Sigfox device. Why are they not coming through? Is the device not working?
Answer:
Sigfox devices need to be thought of differently to normal cellular tracking devices. It is good that you are noting the differences and limitations of the technology.
The short answer is: Sigfox Oysters cannot confirm that the network received their messages. If the Sigfox network did not hear the message when it was sent by the device, it will be lost. The message may not be heard for a variety of reasons: gaps in coverage, adverse network conditions, poor installation.
Sigfox trackers need to be thought of as asset locating devices, not traditional tracking devices. If you want a complete set of data without any gaps, please consider one of our cellular based trackers, where receipt of messages can be confirmed. There are advantages and disadvantages of both technologies.
The advantages of Sigfox:
- Low battery cost of transmission: send many more messages than a traditional cellular device on the equivalent set of batteries
- Low $$$ cost of transmission: a device should be cheaper to run on Sigfox that it would be with a SIM card in it.
So why the missed updates?
Sigfox messages are generally not acknowledged. The cost and number of downlinks in Sigfox pricing plans is structured to discourage communication back to the device. This means the device has no way to know whether a message has been received by the Sigfox network.
The network is designed to maximise the chance of reception, but there will always be dropped messages. The chance of missed messages is higher in the early days of a network roll out - coverage may be sparse. This will improve as your Sigfox network operator continues to roll out the infrastructure.
You can identify missing messages:
You can inspect the sequence number in our telemetry view to see which messages have gone astray:
https://telematics.guru/Asset/Telemetry: use Analogue 10 by default
https://telematics.guru/Asset/IOTelemetry: sequence number on the far right
In this screen shot, note the 2 missing messages between 227 and 230. Messages 228 and 229 were never heard by the Sigfox network.
