Secured SMS in Legato AF 19.02.0

The release notes for Legato 19.02.0 talk about secured SMS wakeup requests.

How do I go about using secured SMS or is this something that is built into the framework that I don’t need to be concerned with?


Any update on sending secure SMS messages. I really want to include this in my product.


Hey Darren,

I was also curious about this feature, so I bisected the commits in the range [19.01.0, 19.02.0]. I grep’ped the content of each commit message and the content of the commit and this seems to be the only relevant commit between those releases: Fix for SMS not being deleted by AVC · legatoproject/legato-Service-AirVantageConnector@b6f115c · GitHub . Not certain if this change is what the release notes refer to.

I believe @prushp maybe be able to help here.


Thanks for the detailed work. I maybe missing something here but I can’t seem to draw any connection between the changes you pointed and “secure” as the release notes state.

This seems to be more like a bug fix.

Hey @dbeckwith,

I would agree. It may be worth analyzing more of the submodules specified in the Legato repo manifest. I focused on the AirVantage Connector service since I figured that’s where it would live.

Hello Darren & Nick,

You are referring to a feature that was added in Legato 19.02, and then removed in 19.04.

The feature description was:

  • my device is currently in a low power consumption mode,
  • it receives a secured SMS sent by AirVantage cloud,
  • this wakes up my device,
  • le_avc checks that this SMS is applying to my device,
  • this SMS allows my device to “immediately” trigger a connection to AirVantage LWM2M server,
  • my device proceeds with any notification got from this server (e.g. “upload your sensor outputs”, “update your software”).

Feature addition details: AV SMS WakeUp · legatoproject/legato-Service-AirVantageConnector@92f3d6f · GitHub and Add LWM2M_LEGATO_WAKEUP to the app model · legatoproject/legato-Service-AirVantageConnector@93360b5 · GitHub

Feature removal details: Revert "Add LWM2M_LEGATO_WAKEUP to the app model" · legatoproject/legato-Service-AirVantageConnector@f9d2cfa · GitHub

While waiting for “secured SMS wakeup” to become fully available, you should note that, upon reception of any SMS, devices can already exit from low power mode, and perform any action like calling le_avc_StartSession.