Summary
4G LTE spectrum is gradually being repurposed for 5G networks. This process will be largely complete by 2028, but manufacturers and carriers will continue to support 4G LTE networks for legacy devices via Dynamic Spectrum Sharing (DSS). Today, 4G LTE is a cost-effective, reliable choice for a wide range of IoT and enterprise use cases, while 5G makes more sense for high-bandwidth or ultra-low-latency applications like autonomous vehicles and advanced industrial automation. However, as 4G LTE networks will degrade with the growing support for 5G and 6G, all organizations should now be evaluating the transition to 5G.
When selecting technology for IoT deployments, enterprises need to know how long 4G LTE will be available, whether 5G will make 4G obsolete, and how to plan their investment.
The short answer: At this writing, no carrier has officially confirmed a shutdown date for LTE, and 4G LTE and 5G are expected to co-exist for the foreseeable future. But that doesn't mean LTE performance will stay flat — carriers are continually refarming 4G spectrum for 5G networks, which will cause 4G device performance to degrade over time. At least one major carrier's internal plans (reported, though not officially confirmed) point toward a multi-year LTE phase-out already underway. Organizations should monitor performance of their 4G LTE device networks and plan their 5G migration accordingly, rather than waiting for a shutdown announcement that may never come in the form they expect.
For a deeper technical comparison of LTE and 5G — speed, latency, spectrum bands, and RedCap — see our LTE vs. 5G guide. Here, we focus on the practical question: how long can you rely on LTE, and how should you plan the transition?
Organizations should monitor performance and plan for a 5G upgrade accordingly.
We will explore further in this post.
Key Takeaways:
- Many IoT, industrial, and enterprise deployments still rely on LTE connectivity
- 4G LTE will experience a "soft shutdown" as spectrum is refarmed for 5G
- Most carriers will continue supporting LTE alongside 5G, though the performance of 4G devices will begin to degrade
- LTE often serves as a fallback network when 5G coverage is unavailable
- Organizations relying on 4G LTE networks should begin evaluating a transition to 5G
How Long Will 4G Be Available?
Short Answer: T-Mobile is reportedly the first major US carrier to put dates to an LTE phase-out. According to leaked internal documents reported in late 2025, most of its LTE spectrum will be refarmed to 5G by around 2028, with a narrow legacy LTE channel kept alive until at least 2035 for devices like ATMs and vehicle telematics that can't yet move to 5G. T-Mobile has not made this an official public commitment, and has stated a full shutdown remains years away. Therefore, treat this as a strong directional signal, not a confirmed date. Verizon and AT&T have not announced comparable timelines
However, as we shared in our LTE vs. 5G blog post, while 4G LTE networks are expected to remain operational alongside 5G deployments for the foreseeable future for legacy coverage, performance is expected to degrade in the coming years as carriers actively refarm spectrum for 5G. For this reason, it is important to plan for a "soft shutdown." Monitor the performance of your 4G networks, and your carrier's device-certification policies, since both will change long before any network actually goes dark.
How to Choose Between 4G vs 5G?
The full deployment of 5G means that not only are more devices connected to the Internet of Things, but also those devices are better connected, with higher data transmission speeds, lower latency and lower power requirements. All of this is producing more efficient and more profitable business solutions than were possible in the past.
Given those advantages, some might assume that every new IoT project should be based on 5G. While it's true that some 5G IoT use cases are only possible with 5G, many others can work at significantly lower cost with current 4G LTE technology which, as we've discussed, will be supported in the industry alongside 5G into the 2030s.
Choosing between 4G LTE and 5G means examining both the technical and business aspects of any new project and projecting the long term costs and benefits of either direction. To support your decision-making, we'll consider the benefits of 4G LTE, its projected lifespan and how and when making the leap to 5G makes sense.
What's the Lifespan of a G?
What is the lifespan of a network generation? Good question. Broadly speaking, a new generation (or "G") of cellular technology comes along every 10 years. Looking back, the last two cellular technologies have had a multi-decade lifespan from first release to sunset:
- 2G: 1990–2020, 30 years+
- 3G: 2000–2022, 20 years+
- 4G: 2008+
- 5G: 2018+
Why did the older technologies such as 2G and 3G need to sunset? The reason for this is that the amount of available spectrum is limited. The same spectrum that was used for 2G and 3G was repurposed for 4G LTE to deliver more data at higher speeds.
4G LTE was introduced in 2008 with Release 8 by the 3rd Generation Partnership Project (3GPP), which is an organization that develops standards for mobile communications. The 3GPP issues standard releases with incremental improvements about every other year (3GPP Release 17 is current at this writing) and guides the evolution of the 4G standard and 5G standards.
4G LTE (Long Term Evolution) is a technology that has been proven in both consumer and commercial applications. 4G LTE is flexible. It accommodates, for example, low-power LTE-M and NB-IoT devices that typically transmit only a few KBs of data, as well as devices capable of high-speed Gigabit data transmission. Because of its widespread adoption, 4G LTE is also very affordable.
That said, manufacturers will be reducing support for 4G LTE devices over time and increasing innovation and support around 5G and 6G.
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Will 4G Be Phased Out? The Transition from 4G to 5G and 6G
With the exponential growth of IoT devices in recent years and the aforementioned limited spectrum, the lifespan of cellular technology is getting shorter. 2G and 3G have been sunsetted to make room for the more spectrum-efficient 4G LTE and emerging 5G and 6G technologies.
4G is expected to remain in force into the 2030's with the help of Dynamic Spectrum Sharing (DSS), which shares available spectrum between 4G LTE and 5G devices. DSS provides improved coverage for 5G devices and greater longevity for 4G LTE devices. While most 4G LTE spectrum is expected to be reclaimed by ~2028, legacy support will continue into the 2030s. This means that organizations still investing in 4G-based IoT solutions today should have a 5G upgrade plan in place in the next few years.
To make 5G technology available early and provide a seamless user experience, first 5G networks and devices were available in non-standalone (NSA) mode, which means that a device always connects to the 4G LTE network first, and if a 5G network becomes available, the device uses 5G for additional bandwidth. After NSA was introduced, network infrastructure evolved to enable 5G-only stand-alone mode (SA). This variety of 5G delivered the low latency and ability to connect with massive numbers of IoT devices that are among the primary advantages of 5G.
Today, 5G is the primary network for developed countries, and 6G is following on its heels. The widespread commercial availability of 6G devices is expected around 2030.
Comparing IoT Use Cases for 4G LTE and 5G
The speed and throughput of 4G LTE is adequate for a wide range of use cases. But as technology advances, new applications and use cases for 5G are emerging. Indeed, there are applications that are only possible with 5G's speed and low latency.
Let's consider three commercial examples where the 4G LTE to 5G transition will play out.
- Transportation: Autonomous vehicles need the extremely low latency of 5G with response times measured in milliseconds. Only 5G is capable of that. But many other transportation use cases also benefit from the greater speed and lower latency of 5G as well. These include signal timing, traffic management, and emergency response. These inter-connected applications require sensors, cameras, high-speed networks and 5G cellular routers like Digi TX65 to ensure traffic routes efficiently through cities, as well as the efficient routing of public transportation and emergency vehicles.
- Industrial Internet of Things (IIoT): Industrial automation and Industry 4.0 applications are greatly enhanced with 5G. Robotic controls that previously required the use of cables because of the limited range and the latency of 3G/4G cellular networks can go fully wireless with 5G, enabling more flexible and efficient factories. An example in a more passive industrial setting would be a sensor measuring the fuel level in a remotely situated fuel tank. This use case would also require wireless because of the remote location. But because only a small amount of data is being transmitted periodically, a battery-powered 4G LTE-M or NB-IoT device is sufficient.
- Drones: 5G extends the capabilities of IoT drones by enabling a controller wearing 5G Augmented Reality (AR) goggles to see beyond current line-of-sight limits with low latency and high resolution video. Drones using existing wireless technology, however, are currently operating in diverse use cases such as search and rescue, crime scene investigation and increasingly in package delivery.
How Does 5G RedCap Fit In?
A related development is 5G RedCap (Reduced Capability), a 3GPP standard designed for IoT devices that need more than LTE-M or NB-IoT can offer but don't require the full complexity or cost of mainstream 5G.
RedCap targets use cases like industrial sensors, wearables, and video surveillance, delivering moderate data rates and lower power consumption on the same 5G network infrastructure. For organizations planning a long term migration path, RedCap offers a way to move devices onto 5G networks incrementally, without paying for capabilities the application doesn't need while still utilizing 5G instead of LTE, extending the working life even beyond the LTE sunset.
See our LTE vs. 5G blog post for a deeper dive on 5G RedCap.
Final Considerations: 4G vs. 5G
Organizations that are not ready to upgrade can continue building for the future with 4G LTE technology and validate their applications and business models. They can then refine and expand when the time is right to upgrade to 5G. Fortunately, there is no danger of 4G LTE becoming unavailable for at least another five years. Nevertheless, there are use cases where 5G is a more desirable choice.
At the low end, with LTE-M and NB-IoT, as well as in the mid-tier with cellular speeds below 1 Gbps, 4G LTE is clearly the winner in terms of cost, coverage, and availability. When we look at the high-end with cellular speeds beyond 1 Gbps, 5G may become more appealing, but at a premium. A thoughtful upgrade strategy will save money and headaches.
Positioned as we are, at the point where 5G technology is just starting to become generally available, there are some key considerations and trade-offs as you decide which direction to go with your IoT project. Given the complexity, it's important to work with a knowledgeable solution provider. A good partner can guide you in choosing the right technology for your use case and ensure that you are investing in technology that supports your long-term business goals.
Reach out to discuss your next IoT project and the best technology choice to make it a success.
4G to 5G FAQs
Will 4G LTE be shut down?
No carrier has officially confirmed a shutdown date for LTE, and 4G LTE and 5G are expected to co-exist for years to come. That said, one major carrier's internal plans, which have been reported, but not publicly confirmed, point toward refarming most LTE spectrum to 5G by around 2028, with a narrow legacy channel maintained until at least 2035 for devices like ATMs and vehicle telematics. The practical takeaway: don't wait for a shutdown announcement. Plan your 5G upgrade around gradually degrading 4G performance instead.
How long will 4G LTE be available?
There's no industry-wide end date for LTE, but availability isn't static either. As carriers reallocate ("refarm") LTE spectrum to 5G, LTE capacity narrows gradually rather than shutting off all at once. Organizations should expect LTE to remain usable for years, but with declining performance and tightening carrier activation policies well before any formal retirement; plan your migration timeline around that curve, not around a fixed date.
What is spectrum refarming, and how does it affect my 4G LTE devices?
Spectrum refarming is when a carrier reallocates radio frequency bands from an older network technology (like LTE) to a newer one (like 5G), since 5G is more spectrally efficient in the same bands. For your fleet, this will show up as reduced LTE throughput and coverage, especially at busy sites and cell edges, long before any official shutdown. It's the main reason to monitor LTE performance proactively rather than assuming a stable network until a shutdown notice arrives.
Can my 4G LTE devices stop working before LTE is officially shut down?
Yes. Two things can degrade an LTE deployment well ahead of any formal shutdown: capacity contraction from spectrum refarming, and carrier certification or activation policy changes that restrict new LTE-only device activations. A device can be technically functional and still lose service quality, or be refused a new SIM activation, on a network that's still officially "live." This is why migration planning should be triggered by performance monitoring, not by a shutdown date.
Should I still invest in 4G LTE for a new IoT deployment?
It depends on your deployment's expected lifespan. LTE remains the lower-cost, broadest-coverage option and is a sound choice for short-lived or highly cost-sensitive projects. For deployments expected to run more than about five years, consider 5G RedCap or full 5G instead, since they run on the network layer carriers are investing in, not the one being gradually reallocated.
What is 5G RedCap, and does it change my migration plan?
5G RedCap is a lighter-weight, lower-cost 5G device category built for mid-tier IoT, delivering LTE-comparable speeds at a lower price and power footprint than full 5G, while running on the 5G Standalone core. For migration planning, RedCap matters because it offers a way to move off LTE without paying for full 5G capability you don't need, extending your device's useful life well beyond a comparable LTE-only device. See our LTE vs. 5G guide for a full technical breakdown of RedCap.
How should I plan a migration from 4G LTE to 5G?
Start by monitoring how each device connects over time, i.e. which network it's using and how strong the signal is. Watching for gradual changes here lets you catch problems early, rather than finding out only after a device fails in the field. From there, prioritize devices and sites showing early degradation, favor hardware that supports eSIM (for remote carrier switching) and 5G Standalone, and consider a platform that spans LTE, RedCap, and full 5G so you can match the radio to each site without fragmenting procurement and management.
Is 5G going to make 4G LTE obsolete?
Not in the near term. LTE and 5G will continue to coexist, and many current IoT use cases run perfectly well on LTE today. But "not obsolete" doesn't mean "unchanging." LTE's underlying spectrum is being reallocated to 5G over time, so its performance and availability will gradually decline even while the technology itself remains in use. Migration planning should treat this as a slow transition to manage, not a cliff to prepare for.
Next Steps
Editorial note: This blog post was first published in May of 2020 and was updated in September of 2026.