CDMA vs GSM: Key Differences Explained

Code Division Multiple Access (CDMA) and Global System for Mobiles (GSM) are both communication standards that are used for telecommunication purposes and by phone carriers. Both are older standards and rapidly expiring, having been described by many as entering a state of “terminal decline.” Nonetheless, for some time, they were vitally important standards when it came to telephone use. Furthermore, in places that may not have access to modern technological resources – such as a 4G or 5G network – these standards may still be in use. Let’s review CDMA vs GSM.

CDMA-GSM illustration
Code Division Multiple Access (CDMA) and Global System for Mobiles (GSM) are both communication standards that are used for telecommunication purposes and by phone carriers.

Both Code Division Multiple Access and Global System for Mobiles are radio networks that are used by wireless companies, including AT&T, Verizon, and more. These radio networks allow for multiple types of calls or data to be exchanged at the same time. Both are broad-based radio networks that have a wide range of geographical uses. Both are used for 2G and 3G networks, but as more and more networks switch to LTE or more advanced, CDMA and GSM are less used. Wireless carriers are rapidly moving away from both of these networks.

However, both also have real differences. GSM is a bigger network and used in over 200 countries, while CDMA is more used primarily in the United States, but less so elsewhere. There are also differences in terms of SIM cards and the interoperability of networks. Furthermore, GSM allows you to make calls and send/receive data at the same time, making multitasking easier. CDMA does not make such a distinction, and this can hurt its overall usefulness. CDMA meaning and functioning is thus considered to be less useful and comprehensive as a mobile network.

CDMA vs GSM: Side by Side Comparison



What it is 
Radio networks for a wireless carrierRadio networks for a wireless carrier

Primary Use
Radio systems for use by mobile carrierRadio systems for use by mobile carrier

Code Division Multiple AccessGlobal System for Mobiles


Initial Release 
1995 (by United States cell carrier networks)1984 (limited use)

Technical Committee 

Influential Developers 
Dmitry Ageev, Leonid Kupriyanovich, QualcommEuropean Telecommunications Standard Institute

Open format

Technologies influenced
SIM Cards, LTE, 4G, 5GLTE, 4G, 5G
modern cell communication
Both CDMA and GSM use radio networks for a wireless carrier.

4 Must Know Facts

  • CDMA and GSM are both outdated. AT&T already shut down large portions of its GSM network and will shut down the remainder in February 2022. T-Mobile and Verizon will do the same by December 2022.
  • Phones that only use CDMA or GSM networks – and these are much older phones – will no longer be usable at this point.
  • LTE became the immediate successor to these two networks, with 4G and 5G rapidly replacing LTE.
  • Both networks were once the most technologically advanced way of making mobile calls and sending data. Indeed, CDMA meaning and GSM meaning were once totally associated with the latest in technology. More than 25 years later, that is no longer the case.

CDMA vs GSM: What’s the Difference? FAQs (Frequently Asked Questions) 

Which is better CDMA or GSM?

Since GSM has been more widely adopted internationally, many international travelers used to prefer GSM phones. Furthermore, GSM allows for the simultaneous transmission of data and voice calls, while CDMA does not. As such, the CDMA meaning has always been understood to be a less functional network.

That being said, this is rapidly becoming a distinction without a distance. Many new devices no longer even use these networks, as they are no longer even close to the most modern from a technological perspective. 4G and 5G have eclipsed the usefulness, stability, and speed of CDMA and GSM.

Which carriers are GSM and CDMA?

There are differences. In the United States, Verizon, and Sprint’s former network and US Cellular use CDMA. AT&T and T-Mobile use the GSM network. However, keep in mind that both of these networks are fading away, and cellular phone companies are increasingly not providing customer or technical support for either platform. Even the most basic LTE network is far superior to GSM or CDMA. Indeed, one could argue that the widespread adoption of LTE networks marked the beginning of the end of the usefulness for GSM and CDMA when it came to use among mobile carriers.

Does Verizon use GSM or CDMA?

Verizon uses CDMA, in part because of timing: The switch to a digital network occurred between 1995-1996, and at that time, CDMA was considered to be the best network available. GSM would eventually be considered the more superior network, but at that point, Verizon had already adopted CDMA.

Can phones be both CDMA and GSM?

Yes, but these are “newer” phones. Typically, older phones will run either Code Division Mobile Access OR Global System for Mobiles, not both. However, even these newer phones that would run both networks are now woefully out of date.

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