How to Prepare for Life After NB-IoT

Last November, the IoT world was caught off guard by AT&T’s announcement to discontinue its support for Narrowband IoT (NB-IoT) by Q1 2025. For many, this came as a big surprise. NB-IoT was considered the prodigy technology, promising low power, long-range, and low-cost connectivity. While NB-IoT never reached mass adoption in the US, this decision still struck as a blow for the ones who did invest in the technology, and raised concerns about its validity among people outside the US.

This article is for everyone who’s – at least – slightly worried about what will happen to their deployed NB-IoT devices in the US or abroad. Let’s explore the potential scenarios and actionable mitigation plans to minimize risks.

Would AT&T Pave the Way for Others?

Currently, AT&T is the only US operator who announced plans for discontinuing its NB-IoT network. This does not spell the end of the technology globally. Major US NB-IoT providers like Verizon and T-Mobile seem to continue running their networks. AT&T aims at moving devices to their LTE-M network, as this technology is more versatile, allowing for higher data throughput, fewer roaming issues, and better coverage in the US. Although we have to guess the real reason for AT&T to make this call, the decision is likely driven by optimization as it removes the need to maintain an expensive network and keep the spectrum allocated for a technology not used at scale. In my opinion, offering two highly interchangeable technologies (NB-IoT and LTE-M) created unnecessary confusion and complexity for the market. 

Whereas the US struggled to achieve mass adoption, partly due to limited network availability, NB-IoT remains a dominant connectivity solution across many countries in Europe and Asia. Inspiring examples include the wide use of emergency warning beacons for car owners in Spain and the strong foothold in metering across Europe and China.

As long as Mobile Network Operators (MNOs) can sustain revenue from their networks, it’s unlikely they’ll phase it out. Let’s also not forget that NB-IoT is officially included in the 5G specifications, indicating long-term support for the technology.

If you have NB-IoT devices running in the field, don’t panic just yet. Regardless of the SIM provider you’re working with, you have two options to consider:

1. Changing the radio access technology or
2. Switching network providers by updating roaming settings

Mitigation Plan 1: Change Radio Access Technology

Fortunately, most IoT modules supporting NB-IoT also support LTE-M. Modules typically select the optimal network and technology based on signal quality and internal radio settings. Devices with roaming enabled will automatically switch networks or technologies if the primary connection fails.

Once AT&T shuts down its network, your devices will automatically switch to another technology or network if set up correctly. However, rather than waiting for the network to become unavailable, you may want to stay in control of transitioning to another technology. This also allows you to test the process with a subset of devices before rolling out updates to your entire fleet.

Assuming your cellular modules support LTE-M, and you have remote access to update configurations, you can update the radio access technology (RAT) using a simple AT Command. You can lock a module to a specific technology or network, but this disables the module from automatically switching to a more preferred network or technology. Instead, you can define a preferred RAT to guide the module’s selection process and prefer LTE-M over NB-IoT.

Setting a preferred RAT is a proactive measure that keeps you in control of the transition to LTE-M. 

For Nerds: Updating RAT Preferences with AT Commands

1. Configure your module to automatically select the best available network.

   
   AT+COPS=0
    

2. The AT Command to set the preferred technology depends on the module you’re using. For the Nordic nRF9160, the following command can be used to prefer LTE-M over NB-IoT:
   
   AT%XSYSTEMMODE=1,1,1,1
   
   Explanation of the variables in the command:
   
   1: Enable LTE-M 
1: Enable NB-IoT 
1: Enable GNSS
1: Prefer LTE-M

Consult your module’s AT Command documentation for specific syntax. 

Mitigation Plan 2: Change Network Provider by Updating Roaming Settings

If remote access to your devices is unavailable or your modules only support NB-IoT, consider switching to another Mobile Network Operator (MNO) that supports NB-IoT. Most MVNOs support multiple mobile networks. In the US, Monogoto works with both AT&T and T-Mobile. Since T-Mobile still supports NB-IoT and is likely to keep doing so, devices with roaming enabled should automatically switch to T-Mobile when AT&T’s network becomes unavailable. 

Again, if you yourself want to stay in control and decide when your devices migrate to another network, you can update the roaming settings and disable your devices from connecting to AT&T. Monogoto has a set of Software Defined Connectivity tools to manage these roaming settings from the cloud. (Not using Monogoto? Check with your connectivity operator to validate if they support this feature.) 

Once these settings are updated, your devices will automatically reconnect to T-Mobile (assuming this network is within range). To speed up this process, you can initiate a reconnection via the Monogoto platform.

By updating your roaming settings, you can ensure seamless transitions without manual intervention. 

Conclusion

While AT&T’s decision to discontinue NB-IoT might seem alarming, the technology’s future remains strong globally. By taking proactive steps, either switching to LTE-M or updating your roaming settings, you can mitigate potential risks and maintain seamless IoT operations. The key is to stay in control of your transition plan. Test changes at a small scale first and leverage the tools provided by your connectivity provider.