Sigfox network localization

The Sigfox network localization service is called Atlas. When the tracker sends a Sigfox message it is received by all the Sigfox base stations in the area. The message and its RSSI is logged in the Sigfox cloud service. Based on the RSSI and the position of the base station a rough estimation of the trackers' position can be estimated using triangulation. This type of localization is automatically done for every message transmitted and has therefor no additional impact on the battery life of the tracker. Because the RSSI is strongly influenced by reflections on building/objects and the distance between base stations is large, the accuracy of network localization is low (order of magnitude: kilometers).

With every communication over Sigfox the network tells us which cells received the data and the sigfox back-end provides us with a network location for all transmissions, but not all of this information is shown on the journey, locations or tracker detail pages (it is in the device messages, see the Q&A section).

Q & A Sigfox network localization

Why is the network location not used?

When you look into the device messages sometimes you see that a network location is captured, but it is not shown on the interface. Why is this?

Device messages? For every device you can look at the device messages when going to Home → Asset list → select tracker → select Device message tab.

This view is only relevant for people that want to look deeper into the working of the way locations and messages are being captured and send over the internet.

In the screenshot below you see two messages from the format: location_update .

the first one (with backendSeqNbr: 3386) will be shown on the interface. The second one (with backendSeqNbr: 3387) will not be shown on the interface.

Why is this? It is because the network locations match with the receival time of the message. So it is not always the time when the event happened. This means that while you can see network locations on all device messages not all can be considered for use in locations, journeys or tracker status. The gap between event time (in the message) and receive time should be less than 30 minutes.

When communicating over the Sigfox network, the Data recovery algorithm is often used because quiet some messages do not arrive live. The recovered messages will not have a usable network location. You will see them in the device messages but not on the other pages.