What’s the 3G Sunset and How Will It Affect Existing IoT Deployments?
What is the 3G Sunset?
As cellular networks prepare to roll out 5G, they are continuing to shut down older systems. Many providers have already retired 2G, and 3G networks are next on the list. The 3G sunset will allow network operators to create space in the radio spectrum for newer, faster technology. Coming on the heels of the 2G sunset in many places, the transition is creating challenges for deployments that depend on older systems. And many deployments do—to date, 2G and 3G are still the most commonly used technologies for IoT deployments.
It’s important to remember that while carriers do not guarantee 3G service after a certain date, your devices will probably not lose connectivity right away. The situation is more like highway maintenance—when a government stops maintaining a road, it doesn’t become defunct immediately. But over time, it will deteriorate and become unusable. That’s why it’s important to plan now for the 3G sunset and prepare your IoT deployment for migration to newer cellular technologies.
When Will the Sunset Happen?
There’s not a single cutoff date for 3G technology. Carriers around the world have different strategies for updating their infrastructure. Some have already retired both 2G and 3G (Verizon, for example, no longer guaranteed 2G and 3G service after the end of 2019), while others are holding onto one or both for the foreseeable future. It’s important to know which carrier network your devices use so you can adequately prepare for the sunset.
Here are a few dates to be aware of:
- Upcoming 3G sunsets in the U.S.:
- AT&T in February 2022
- Sprint on 12/31/2022
- Upcoming 3G sunsets in Canada:
- Bell on 12/31/2025
- Telus on 12/31/2025
- Rogers on 12/31/2025
- 3G sunsets in Asia:
- Many carriers in Asia have already enacted a 3G shutdown, including China Mobile, China Unicom, and all carriers in Taiwan.
- Airtel (India) in March 2020
- Telstra plans a complete 3G shutdown by 2030
- Vodafone turned off 2100MHz in 2019, but continues to support 900MHz
- Most European carriers will phase out 3G in the next few years:
- EE by 2022
- Three and Vodafone in 2020
- Orange France by 2021
- Sweden Telenor by 2025
Why are some regions phasing out 3G before 2G?
While most Asian and American network operators are doing away with 2G service, Europe’s carriers are retaining it—often significantly longer than they’re keeping 3G service. That’s because 2G is still used for IoT applications in Europe. Because many IoT use cases (smart meters, for example) only need to transmit small packets of data, 2G can actually serve quite well. They don’t need the lightning-fast speeds of 5G or even 4G, and many older M2M devices already have 2G capabilities built in, so it makes sense to carry on with existing infrastructure until other connectivity options such as Cat-M1 and NB-IoT are accessible across Europe, the Middle East, and Africa.
How will the 3G sunset affect existing IoT deployments?
In most places, 3G coverage will diminish slowly. Carriers will cut back service in lower volume areas, creating gaps in service that will prove problematic to deployed IoT devices scattered over large areas (or in use cases that involve devices in motion, such as fleet management).
The sunset impacts every 3G device, from IoT sensors to tablets and smartphones, regardless of manufacturer. It’s important for IoT managers to inventory their devices to be sure which ones will be affected. Even if a device was activated recently, it might not be safe—if it was manufactured prior to 2018, it could be limited to 3G connectivity.
To maintain consistent coverage, you will need to migrate service and devices to 4G or another option such as a low-power wide-area network (LPWAN).
What are the benefits of switching to 4G LTE?
For some IoT use cases, 4G LTE will be the most logical migration destination for your deployment. 4G offers much better coverage, and carriers are not planning to sunset this technology in the near future, so it’s also future-proof. Here are a few other advantages of 4G LTE versus 3G:
- Higher bandwidth
4G LTE data speeds are typically between 20–50 Mbps, up to 10 times faster than 3G. If your deployment involves high volumes of data (such as streaming surveillance video), this will benefit you.
- Lower latency
Latency can affect deployments that depend on real-time data delivery—for example, connected cameras or other devices used by first responders during emergencies. 4G LTE offers lower latency (or less of a delay between transmission and reception) than 3G, at an average of 53.1 milliseconds.
On the other hand, 4G LTE typically involves more expensive hardware and more power consumption. If your deployment doesn’t need high bandwidth connectivity, it might be better to explore other LTE standards—such as the lesser-known Cat-1—that were designed with IoT sensors in mind.
What are the benefits of switching to LPWAN?
Newer LTE IoT standards can lower costs and reduce power usage while allowing long-distance connectivity. Designed specifically for IoT devices, these standards can be excellent options depending on your use case. Here are a few of the most common ones:
- LTE Cat-1
Although not as well-known, Cat-1 is flexible—able to support both low-power connections as well as high bandwidth needs, depending on the use case. And since it can handle voice and mobile IoT applications, Cat-1 is a viable choice for asset tracking, remote sensors, wearables, and micromobility rentals. While it does consume more power and has a slightly shorter signal than NB-IoT and Cat M-1, it is currently more widely supported by carriers around the world, making it a better option for global IoT deployments.
- LTE Cat-M1
Designed as a low-power connectivity option for IoT deployments, Cat-M1 promises an average of 10 years of service on a 5WH battery. It operates on a 1.4 MHz spectrum and allows upload speeds of 200–400 kpbs. Cat-M1 hardware boards are much less expensive than other options and provide excellent coverage—and the technology is compatible with existing cellular data services, making it a future-proof choice. One con of Cat-M1 is that carriers haven’t fully standarized international roaming, making things tricky if your devices are deployed overseas.
- NB-IoT (Cat-M2)
Similar to Cat-M1, NB-IoT uses DSSS modulation rather than LTE radios, resulting in a greater initial cost for operators wishing to deploy with this standard. NB-IoT sends data directly to the server, eliminating the need for a gateway—and resulting in some cost savings. Like Cat-M1, the international roaming situation with Cat-M2 is still in flux, so it might not be the best choice for a global IoT deployment at this point.
Migrating Your Deployment
The 3G sunset can cause temporary headaches as you rethink your IoT strategy, but it’s also an opportunity to restructure long-term plans and bring your deployment up-to-date with the technology that’s best for your use case. Some of the options may also result in both short-term and long-term cost savings, which is never an unwelcome surprise.