CDMA (Code Division Multiple Access) and GSM (Global System for Mobiles) are shorthand for two older radio systems used in cell phones. These networks support 2G (second generation) and 3G (third generation) devices and were first seen in the US in the 1990s.
But millions of people are still using devices that require one or the other of these older networks. If you have an older phone using this technology, it’s time to replace it with a 4G device.
The new global network is 5G-NR. This is at the very beginning stages. To keep things in perspective, 4G started implementation in 2010 and will continue to be supported for many years.
In the US:
- Verizon plans to turn off 2G and 3G at the end of 2019
- T-Mobile will turn off 2G and 3G at the end of 2020
- AT&T has already turned off 2G
- AT&T and Sprint will keep 3G running until 2022
– according to PC Magazine contributor Sascha Segan May 24, 2019
Learn more in this article from PC Magazine https://www.pcmag.com/news/300986/cdma-vs-gsm-whats-the-difference