CDMA vs. GSM: What's the Difference?


5/8/20232 min read

For decades, CDMA and GSM have been the most prominent mobile communication technologies and are still evolving. Even after the emergence of faster and more efficient communication systems, they’re still prevalent in the USA. Although both are telecommunication technologies converting mobile phone data into radio frequency, they aren’t compatible with each other. Various features differentiate GSM from CDMA, and understanding their characteristics will help you decide which one is best for you.

Here are some differences you need to know about CDMA and GSM-

What is CDMA?

CDMA or Code Division Multiple Access is a radio telecommunication standard introduced as the standard of wireless communication in 2G and 3G generation. It does not require SIM cards. Instead, it works on ESN (Electronic Serial Number) and authenticates a phone directly. If the user wishes to change their number or network type, proper procedures need to be followed. It is used in UHF (Ultra High-Frequency cellular systems).

Networks Using CDMA-

The standard networks using CDMA in the US are Verizon, Sprint, US Cellular, and their smaller subsidiaries such as Tracfone and Boost Mobile.

What is GSM?

GSM or Global System for Mobile Connection is also called the second-generation standard for mobile networks. Unlike CDMA, GSM authenticates SIM cards. If a user wishes to change their mobile network, they only need to switch their SIM cards and not the phone. It was first introduced as 1G technology and has evolved to 4G, currently working in most countries worldwide.

GSM introduced the first SMS (Short Message System) service and also paved the way for various wireless services like GPRS (General Packet Radio Service) and UMRS (Universal Mobile Radio System).

Networks Using GSM-

Any networks not using CDMA use GSM, AT&T, T-Mobile, and many prepaid cellular providers.

Differences Between GSM and CDMA-

Flexibility: Since GSM devices use SIM cards that can be replaced whenever required, it is a more flexible option. On the other hand, CDMA works on ESN and provides less flexibility to the users.
Frequency: GSM runs on three different radio frequencies of 900 MHz, 1800 MHz, 1900 MHz, with 900 MHz being the most common. CDMA operates on the frequency range of 850 MHz to 1900 MHz.
Popularity: GSM phones have a worldwide reach with almost all the countries using the technology. In contrast, CDMA is only prevalent in the US, Canada, and Japan.
Security: CDMA is based on the spread spectrum technology and optimally uses all available bandwidth to readily encrypt the transmitted data. Moreover, signal detection is more difficult in CDMA than GSM, which operates on a wedge spectrum.
Data Transfer Rate: CDMA uses EVDO data transfer technology that provides a high data transfer speed of upto 2 Mbps. In comparison, GSM uses EDGE (Enhanced Data Rates for GSM Evolution) with a maximum downloading speed of 384 Kbps.

About i3 Mobile

We are one of the best GSM network providers in the USA. If you are looking for a Netgear nighthawk unlimited data plan that offers high-speed connectivity across the US, i3 Mobile should be your one-stop destination. Our high-speed unlimited data plan just costs $169 per month and provides a lightning-fast speed of more than 100Mbps. You can reach out to us at (855) 546-0085 or drop an email at to know more about gsm data-only plans.