When using 1GLOBAL SIMs, SIM OTA updates are initiated by the network and are not reliably exposed to the application layer on the nRF9160 modem. The device cannot determine when an OTA update is in progress, and may detach from the network before the update is complete.

To make sure OTA updates are received reliably while preserving battery life, the device can periodically remain attached to the network for an extended duration, independent of whether an OTA is known to be pending. Two upload parameters control this. Both default to 0, so the behaviour is off until it is configured.

Parameter reference

Days Between Extended Network Connection Attempts

• Gives periodic opportunities for SIM OTA updates to be delivered, even when no explicit OTA indication is available.
• When set to a value greater than zero, the device counts days since the last extended upload.
• Once the configured interval has elapsed, the next network connection remains attached for the duration set by Extended Upload On-Time.
• The network connection must be successful for the counter to increment.
• A value of 0 (default) disables this behaviour.

⚠ A failed connection attempt does not advance the day counter. If the device cannot reach the network, the extended attachment is retried on the next successful connection rather than skipped.

Extended Upload On-Time

• Specifies, in seconds, how long the device remains attached to the network during an extended upload attempt.
• Allows enough network attachment time for one or more SIM OTA updates to complete successfully.
• Applied when a network connection succeeds and Days Between Extended Network Connection Attempts has reached its configured value.
• A value of 0 (default) results in normal upload behaviour, with no extension.

Behaviour on device reset

An extended attach window is also needed during initial commissioning, so that any queued SIM updates are applied straight away. If Days Between Extended Network Connection Attempts is non-zero, an extended network connection also occurs on device reset, and the day counter is reset accordingly.

Setting the parameters in Device Manager

1. In Device Manager, open the Device Grid and select the devices to update.

2. Open Edit System Parameters. Click + Add Advanced Parameters and select Extended Network Connection.

3. Set Days Between Extended Network Connection Attempts to the interval, in days, at which an extended attachment should occur.

4. Set Extended Upload On-Time to the number of seconds the device should stay attached during those uploads.

5. Click Update. The parameters are applied to the device on its next connection.

⚠ Both parameters are required. Setting an interval without an on-time, or an on-time without an interval, leaves the device on normal upload behaviour. Both values must be greater than zero for extended attachment to take effect.

Power consumption

Extended attachment is a trade-off between update responsiveness and power consumption. A shorter interval and a longer on-time increase the chance of an OTA update being delivered promptly, and increase the energy used per cycle. Choose values against the expected battery life for the deployment.

Next steps

For background on SIM identifiers and how to look them up, see A Guide to SIM Cards, ICCIDs and Reports. For network selection and coverage, see Connectivity — LTE-M vs NB-IoT, Coverage, Providers and Roaming.