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nRF9160 Cannot connect to LTE after 30x modem on/off

Very similar to this post, my use case involves cycling the modem between online and offline ("AT+CFUN=1" and "AT+CFUN=4"), for enabling GPS and also for reducing power consumption while the device sleeps for extended periods of time (currently 30 minutes but possibly 3 hours). My time between reconnects is only every 30 minutes, meaning I'm reconnecting 2x per hour. The GSMA specified Radio Policy Manager (RPM) feature for blocking the ATTACH command (TS.34_8.2.4_REQ_010, page 43 in this pdf) specifies 30 activation/deactivation requests per hour. I still ran into the same issue even though my 30 activation/deactivation requests occurred over the span of 15 hours. If this is being blocked at the modem firmware level then I believe this is a bug with the modem firmware.

I'm running on a nRF9160-based platform using modem firmware v1.0.1.

Currently, my best workaround idea is to cycle power after 29 connections, but this is not a clean solution. I'm also exploring the usage of PSM, but I've found very little documentation for how to actually implement this on the 1.0 release of the nrf SDK. I would greatly appreciate some help with this.

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  • Hi,

    If this is being blocked at the modem firmware level then I believe this is a bug with the modem firmware.

    You are correct. I can confirm that this is a modem firmware bug. It will be fixed in the next modem firmware release(v1.1.0). I expect it to be released within 1-2 weeks.

    I'm also exploring the usage of PSM, but I've found very little documentation for how to actually implement this on the 1.0 release of the nrf SDK.

    I believe it would be better to use PSM than deactivation if sleeping "only" 30 minutes. You can take a look at this sample here that uses PSM. If you still have issues with PSM, please create a new dedicated case for that.

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  • Hi,

    If this is being blocked at the modem firmware level then I believe this is a bug with the modem firmware.

    You are correct. I can confirm that this is a modem firmware bug. It will be fixed in the next modem firmware release(v1.1.0). I expect it to be released within 1-2 weeks.

    I'm also exploring the usage of PSM, but I've found very little documentation for how to actually implement this on the 1.0 release of the nrf SDK.

    I believe it would be better to use PSM than deactivation if sleeping "only" 30 minutes. You can take a look at this sample here that uses PSM. If you still have issues with PSM, please create a new dedicated case for that.

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