# Generations, refarming and sunsets

A generation is a set of radio and core standards. Refarming moves spectrum from an older generation to a newer one; a sunset is the date a network stops serving a generation. 5G non-standalone shares an LTE anchor; standalone uses a 5G core. A device survives only if its bands, voice path and firmware fit the next network.

- 5G NSA uses an LTE anchor and the existing core; SA uses a new 5G core.

- Refarming reassigns spectrum from an older generation to a newer one.

- A sunset date is a device deadline, not only a network deadline.

- A device needs the right bands, VoLTE support and firmware configuration to survive a change.

## 5G is not one thing

A generation is a set of radio and core standards, not a speed label. 2G introduced digital voice and SMS and, later, packet data through GPRS/EDGE; 3G brought mobile broadband, 4G made the network all-IP, and 5G introduced a new radio and a new core. Each generation changed both the radio and the way the network handles a session.
5G arrives in two common architectures. Non-standalone 5G uses an LTE anchor for the control plane and the existing 4G core for the session; the 5G radio adds capacity where it is deployed. Standalone 5G uses the new radio with a 5G core, so the session is native 5G from the start.
The difference matters to a buyer. An NSA device depends on the LTE anchor, so it shares the anchor's coverage and capacity. An SA device depends on standalone 5G radio coverage, which can be thinner in the first years. A 5G icon on the screen does not tell you which architecture is in use, and it does not tell you the speed.
The same handset can move between the two. The network decides what it offers, the device decides what it supports, and the subscription decides what is allowed. A device that supports SA on paper may still attach through NSA where SA is not deployed.
Generation names describe the radio and the core, not the experience. A 4G cell with a wide channel and a good backhaul can beat a 5G cell with a narrow channel and a weak backhaul. Compare the band, the channel width, the cell density and the measured throughput before you compare the label.

### Four generations, one after another

Each generation changed the radio and the core. The timeline shows the order, not a date for every market; deployment dates differ.

Alt: A timeline with four generations: 2G for digital voice, SMS and later packet data, 3G for mobile broadband, 4G for all-IP data, 5G for a new radio and core.

The timeline runs from 2G to 5G. 2G introduced digital voice and SMS and, later, packet data through GPRS/EDGE. 3G brought mobile broadband. 4G moved the network to all-IP. 5G introduced a new radio and a new core, with non-standalone and standalone variants. The order is common; the dates are not, because each market licenses and deploys on its own schedule.

| Item | Value | Note |
| --- | --- | --- |
| Generations · 2G | Digital voice and SMS |  |
| Generations · 3G | Mobile data |  |
| Generations · 4G | All-IP data |  |
| Generations · 5G | New radio and core |  |

Source: 3GPP Release 15: non-standalone and standalone 5G (https://www.3gpp.org/specifications-technologies/releases/release-15)

## Refarming moves spectrum; a sunset removes a generation

Refarming reassigns a frequency range from an older generation to a newer one. When a 2G or 3G network closes, its carriers can be reused for 4G or 5G, often with a wider channel and a more efficient radio. The spectrum does not disappear; it changes job.
A sunset is the date a network stops serving a generation. After that date, a device that works only on the closed generation has no service, even if the SIM is active and the subscription is paid. The date is set by the operator and sometimes shaped by the regulator, so it differs by market and can move.
Refarming and a sunset are related but not the same. An operator can refarm part of a band while the old generation still runs on another part. A device can lose its band before the official sunset, or keep working on a remaining carrier after it. Ask for the carrier and the date, not only the generation.

### The order of retirement

The track shows the usual order: 2G voice and SMS, 3G capacity refarmed, 4G with VoLTE as the voice baseline, 5G for new devices. Dates differ by market.

Alt: A sunset timeline with four stages: 2G voice and SMS, 3G capacity refarmed, 4G VoLTE baseline, 5G new devices.

The track shows a common retirement order. 2G carries voice and SMS for the oldest devices. 3G capacity is refarmed to newer generations. 4G becomes the voice baseline through VoLTE. 5G serves new devices and new capacity. The sequence is a pattern, not a schedule for a given country; confirm the date and the remaining carriers for each market.

| Item | Value | Note |
| --- | --- | --- |
| Network retirement · 2G | Voice and SMS only |  |
| Network retirement · 3G | Capacity refarmed |  |
| Network retirement · 4G | VoLTE baseline |  |
| Network retirement · 5G | New devices |  |

Source: GSMA: 2G/3G sunset and VoLTE roaming work (https://www.gsma.com/get-involved/working-groups/working-groups/volte-roaming/)

## A sunset is a device clock

A 2G-only tracker works today. Its risk is a date it cannot see: when the 2G carrier closes, the device stops reporting. The same risk applies to a 3G-only meter, a 4G device without VoLTE, and a 5G device that supports a band the local network does not use.
Check five things on the device, not only the generation. The radio module must support the bands the next network uses. The SIM or profile must support the same generations. The firmware must be configurable for the new APN and the new voice path. The device must support VoLTE if it carries voice. The power and thermal design must survive the new radio's behavior.
The trap is a device that supports 4G data but not VoLTE. It works on data today and loses voice when 3G closes, because the circuit-switched voice fallback disappears. A second trap is a module that supports the right band but ships with firmware that does not enable it.
Certification is a separate clock. A module that is certified for a market today may need a new approval when the radio or the firmware changes. Ask whether the replacement path keeps the existing certification or starts a new one, and how long that takes.

The scenario uses a generic country view. Confirm each date with the operator and the regulator for the market you ship to.

[Open the tool](/en/tools/network-sunset/?src=learn-generations-refarming-and-sunsets&scenario=country-generic&country=MX)

## What to ask before shipping

Ask for the sunset date per market in writing, with the carrier and the generation it applies to. Ask what the fallback bearer is: 4G data, VoLTE, or a lower generation that will remain. Ask which bands the device must support and which of them the target network uses.
Ask for the firmware and configuration path. A device that needs a new APN, a new IMS setting or a firmware update to stay connected is a device with an operational task, not a finished product. Ask who performs the update and how a fleet in the field receives it.
Ask for the replacement path and the lead time. A 2G module can be discontinued before the network closes, and a replacement module may need a new certification. The decision belongs in the product plan, not in the month the network switches off.

### A 5G icon means a 5G core

Myth: if the phone shows 5G, the session runs on a standalone 5G core.
Fact: the icon can appear on non-standalone 5G, which uses an LTE anchor and the 4G core. The icon shows a radio technology, not the core architecture.

### Check your understanding

**A 2G-only tracker works today: what is the risk?**

It stops working when the 2G carrier closes. Ask for the date, the replacement module and the lead time before the network change, not after.

**What is the difference between NSA and SA for capacity?**

NSA adds 5G radio capacity on an LTE anchor and an existing core, so it shares the anchor's coverage and capacity. SA uses a 5G core and can use 5G capacity without the LTE anchor, but its coverage can be thinner at first.

**What do you ask for in writing before shipping?**

The sunset date per market, the carrier and generation it applies to, the fallback bearer, the required bands, the VoLTE requirement and the firmware update path.

## FAQ

**Does a 5G device work on every 5G network?**

No. It needs the bands the network uses, the right core support and the right firmware. A 5G icon does not prove any of those.

**Is refarming the same as a sunset?**

No. Refarming reassigns spectrum to a newer generation. A sunset ends service on a generation. One can happen without the other.

**Why does voice fail on a 4G device after 3G closes?**

The device may not support VoLTE, and the 3G network was carrying the voice fallback. Without VoLTE, data works and voice has no path.

## Sources

- [3GPP Release 15: non-standalone and standalone 5G](https://www.3gpp.org/specifications-technologies/releases/release-15) — Accessed: 2026-10-19
- [GSMA: the MENA region embraces 5G Standalone (1 October 2025)](https://www.gsma.com/solutions-and-impact/technologies/networks/gsma_resources/the-mena-region-embraces-5g-standalone-to-unlock-127-billion-enterprise-revenue-opportunity/) — Accessed: 2026-10-19
- [GSMA: 2G/3G sunset and VoLTE roaming](https://www.gsma.com/get-involved/working-groups/working-groups/volte-roaming/) — Accessed: 2026-10-19
- [Norwegian Communications Authority (Nkom): Be prepared for the 2G network shutdown (12 June 2026)](https://nkom.no/fysiske-nett-og-infrastruktur/vaer-forberedt-til-2g-nettet-stenger) — Accessed: 2026-10-19

Updated: 2026-10-19