3G Network Sunset in 2022 impact on 4G devices

Carriers have announced that they will be shutting down their 3G network in 2022.  The sunset of the 3G networks may impact some 4G LTE devices.  This situation could cause certain 4G LTE devices using voice centric modems to stop working after the 3G network sunset due to the configuration settings.

Digi has identified the list of modems affected, and the corresponding Digi products that have incorporated these modems.

What Happens If I Do Not Update?

If the affected devices are not updated before carriers sunset their 3G networks in 2022, the devices will no longer be able to Register on the carrier network.  The SIM cards within the hardware will look like they are deactivated if the firmware update is not applied.

1)  AT&T has announced they will sunset their 3G network on 2/22/22. 

2)  T-Mobile has announce they will be shutting down the following networks on the given dates:

  • As of March 31, 2022, Sprint’s older 3G (CDMA) network will be retired
  • As of June 30, 2022, Sprint’s LTE network will be retired
  • As of July 1, 2022, T-Mobile’s older 3G UMTS network will be retired

      More information on the T-Mobile shutdown can be found on their website here.

What You Need To Do and What Devices are Affected?

Digi has provided firmware updates for the affected devices to avoid any issues when the 3G network sunset occurs.  Customers are encouraged to update their devices as soon as they are able.
A complete list of products that need firmware updates to avoid connectivity issues when the 3G network sunset occurs can be found here.


Connectivity issues identified during the AT&T 3G Shutdown

Update 3/23/22

Digi is receiving reports of customer’s devices going offline identified during the AT&T 3G network shutdown.  Below are a few scenarios that have been seen, and what can be done to correct the issues:

1)  Some WR21, WR31, and WR44 devices with Sierra Wireless MC7354 cellular modules may be using Verizon firmware instead of AT&T firmware.  Being on this firmware will cause connectivity issues identified during the AT&T 3G shutdown.  Switching to AT&T firmware will resolve most connectivity issues.  Information on changing the carrier firmware can be found in this document:  QN39

2)  Devices using the 1002-CM04 CORE radio (using the Telit LE910-NAv2) and IX14s with part number IX14-M601 need an additional update beyond updating the firmware to or later.  Please see the updated notes in the What You Need To Do and What Devices are Affected? section above.

3)  Devices running the DAL operating system may need the default IPv4/IPv6 dual-mode disabled for the cellular modem.  If this is the case, enable the IPv4 only option if the SIM card does not provide both types of IP addresses.  Refer to the product manual for your device on locating this option to disable it.

4)  The APN associated with the SIM card may not be setup as a proper LTE APN.  Please contact your AT&T representative to review your data plan to ensure it is setup properly for LTE service.  For example, APNs such as "nxtgenphone" and "broadband" are known to have issues connecting to the LTE network.

5)  It may be possible that the Digi device is locked to a 3G only mode.  The device will need to be taken out of this mode to gain access to the 4G LTE network.  Please refer to the manual for your specific product for WebUI and/or CLI commands to make this change.

6)  It is important to remember that 4G LTE signal needs to be in the area the Digi device is used in.  The Digi device may need to be relocated to obtain a signal.  Please refer to the following link on performing a site survey with a DAL based product:  https://www.digi.com/resources/documentation/digidocs/90002344/default.htm#device/enterprise/enterprise-site-survey.htm

If you are having connectivity issues, and the above steps are not correcting the problem, please contact Digi Technical Support at tech.support@digi.com for assistance.



Additional Resources and Services


  • Continue to watch this knowledge base article for any additional updates.
  • Contact the Digi Technical Support team at tech.support@digi.com with questions.
  • As a Digi Remote Manager user, the update procedures will highlight how you can update your affected devices quickly and easily over-the-air using Digi Remote Manager
  • If you are not a Digi Remote Manager user, please visit https://www.digi.com/products/iot-platform/digi-remote-manager to get a FREE 90-day trial of Digi Remote Manager to help simplify your update process.

As always, Digi is here to help. The Digi Professional Services team offers expert consulting services for enterprises that need technical assistance with device upgrades. Contact professional.services@digi.com if you would like to review options for updating your devices.

Last updated: Jan 01, 2024

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