We currently believe that existing networks will be turned down on the following schedules (but please see the disclaimers above):
2015 – 2020
In the USA, Canada, and some smaller countries, carriers have already turned down their 2G GSM and CDMA networks, and many others have announced intentions to sunset 2G by the end of 2020 (or fairly soon afterwards). We have been told that some carriers, and most carriers in a few countries, may keep 2G GSM and 2G CDMA going longer for their low-cost 2G handset users and for existing deployments of M2M and IoT devices.
We are unlikely to see many 3G shutdowns before the end of 2020, but carriers have made it pretty clear that these could occur. Most carriers say that they will not turn off 3G until they have completed their build-out of 4G LTE coverage for data and voice services in their service areas. Although voice can be transported over data channels, including 4G, high quality voice may not be available until Voice-over-LTE (VoLTE) has been fully deployed. Since a large number of LTE networks still depend on 2G or 3G networks to carry voice traffic for 4G devices, we expect many carriers to maintain some amount of 3G (or even 2G) coverage to support voice services on their 4G LTE networks. If and once VoLTE is successfully rolled out and becomes the dominant transport for voice service on IP-based networks, we will expect carriers to move more quickly to shut down any remaining 2G and 3G service.
2020 – 2025
We expect that most remaining 2G networks will sunset during this period – particularly in Asia and Europe – and will be removed by 2025. In some low-cost handset markets, such as India and Latin America, 2G GSM networks may continue service through 2025 or later. And 2G CDMA likely will continue in China through the end of 2030. It is possible that carriers will prohibit any new deployments of devices on these technologies, and support only existing devices.
In most countries, 3G sunsets will start during this period. In markets with complete 4G LTE coverage (such as North America) or countries with quick technology changes (e.g., Japan and South Korea), 3G sunsets will almost certainly be completed by the end of this period.
In China, 3G CDMA (EV-DO) likely will continue through the end of 2030 due to the large number of existing handsets that use that technology.
2025 – 2030
All remaining (if any still remain) 2G GSM networks will definitely sunset by the end of this period. In China, 2G CDMA likely will be removed at the end of the decade.
Many 3G networks will sunset during this period. It is highly unlikely that any 3G network will remain operational by the end of the decade, with the exception of China, which is likely to continue 3G CDMA (EV-DO) through the end of this period.