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Cellular connectivity guidelines

In this section:

To ensure the connectivity of the loggers, be mindful of factors in the on-site surroundings that may be detrimental to their efforts to upload data. Review these guidelines to support the connectivity of the Saga™ loggers at your site.

On-site environment factors

Storage conditions

How and where the loggers are stored and handled may have a significant impact on their ability to access the network.

To minimize the risk of issues:

  • Store and handle loggers where they can get a strong enough signal to connect. On-site employees often have a good sense of where these areas are located due to their experience with their own mobile devices.

    If in doubt, refer to the instructions on how to observe the signal strength.

  • Avoid routinely using loggers in basements, freezers, or heavily insulated areas.

    Architecture or building materials such as metal cladding may cause a drop in signal strength.

  • Storage containers and thermal blankets are significant signal suppressors and may cause loggers to struggle to connect.

  • Stacking loggers in between or under multiple boxes or pallets may cause them to be too insulated to connect.

Number of devices on site

In extremely rare circumstances, a large number of loggers have been known to push a telecom infrastructure to its limits. This can occur despite a strong signal, as even the clearest signal is still only a limited resource in bandwidth. If this is an issue on-site, it will cause the loggers to fail and time out in their routine upload during their wake-ups.


If issues at a site are sporadic and seem to escalate along with the number of loggers being processed, it is possible that the serving cell at the site is unable to cope with the load. In this case, we recommend that you contact your local telecom provider to evaluate options for expanding the mobile network capacity at your site.

Preliminary Signal Test Guidelines

Cell coverage can vary extremely on a site-by-site basis. In addition to how the loggers are stored, distance from the nearby towers, built or natural environmental conditions in the area, and the site’s building materials can all have a considerable effect on signal strength.

At sites where there is a suspicion or a history of poor cell coverage, you can easily estimate the general signal strength by using a smartphone:

  1. Verify that the smartphone uses a SIM card from an operator that also services the loggers. Confirm this information with the Controlant project team, as applicable.

  2. Choose areas where the loggers will be used.

    Test the areas where loggers will be received and handled to make sure they have the best connection to upload their data.

  3. Use the smartphone to observe the measured value in the chosen area.

    Signal strength measurement guidelines differ between Apple iOS and Android.

  4. If you are checking multiple areas, it is helpful to note the most common measured value for each area for later comparison.

Interpreting the results

To determine whether the measured signal strength is good or poor, refer to the below table as a guide:

Value in dBm

Cellular signal %

Signal conditions


54 to 100%


-80 to -90

38 to 53%


-90 to -100

22 to 37%


-100 to -113

1 to 21%


> -113


No signal

Further investigation can be performed if the signal conditions are extensively poor or if there are continued problems with loggers failing to connect.