https://devzone.nordicsemi.com/f/nordic-q-a/81520/modem-sleep-notificationsHi, I am developing a simple application where I read some data from a sensor, and publish the data with MQTT. I want to use PSM to conserve battery life, and I am able to turn it on, and its looks like it&#39;s working. I have turned on &quot;MODEM_SLEEP_NOTIFICATIONSen-USTelligent Community 13Mon, 08 Nov 2021 21:18:09 GMThttps://devzone.nordicsemi.com/thread/338015?ContentTypeID=1Mon, 08 Nov 2021 21:18:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9db67fe7-0e15-4442-925a-3492d2c39918DevinCallahan<p>The library you are looking for is the at_notif library at&nbsp;/nrf/lib/at_notif in the NRF Connect SDK.</p> <p><br />The LTE Link Control library at /nrf/lib/lte_link_control has an example of using it.&nbsp; It registers a handler using &quot;at_notif_register_handler&quot; which is then invoked each time any AT messages are received from the modem.</p><div style="clear:both;"></div>