CDMA vs. GSM: What's the Difference?

CDMA and GSM are the two most widely used mobile networking standards for mobile communication. Even though both systems are intended to accomplish the same goal of connecting people over the phone, they take very different approaches.

In this article, you will learn the differences between the two technologies, the advantages and disadvantages of each, and their relevance to the mobile communication experience.

GSM (Global System for Mobile Communication) is a digital cellular communication standard created by the European Telecommunications Standards Institute for 2G and 3G digital mobile networks.

It’s widely available, with coverage in over 219 countries.

It transmits mobile voice and data services over a wireless network.

GSM networks employ a variety of frequency bands, including 900 MHz and 1800 MHz in Europe, Asia, and Africa, as well as 850 MHz and 1900 MHz in the Americas.

GSM employs a variant of TDMA (Time Division Multiple Access) to allocate the same frequency to many users by dividing the frequency bandwidths into different time slots.

It also uses FDMA (Frequency Division Multiple Access), which divides frequency bands into multiple bands, each assigned to a specific user.

While transmitting signals, voice and data are given a channel and a time slot.

In CDMA, voice and data are transmitted simultaneously on the same radio channel through Time Division Duplexing (TDD), separated in time.

When a user dials a phone number, the phone switches to the voice channel, and when there is data usage on your phone, the phone switches to the data channel.

As a result, the user will often receive internet notifications after they finish a call.

GSM allows voice calls and data usage to occur simultaneously, even without WiFi.

CDMA phone calls are cheaper compared to calls made on a GSM network.

Despite having lower call rates, CDMA is primarily restricted to a small number of countries.

As a result, GSM has more options for growth and establishing cell sites across borders.

Unlocked GSM phones are typically less expensive than locked, under-contract CDMA phones because there’s a larger variety of GSM phones available to choose from.

CDMA networks are built on spread-spectrum technology, which makes the best of available bandwidth by allowing each user to broadcast continuously across the whole frequency spectrum.

GSM operates on the wedge spectrum, called a carrier.

This carrier is separated into several time slots; each user is assigned a different time slot.

No other subscriber can use this until the current call is completed.

GSM separates users and cells by using both TDMA and FDMA technologies.

1. Go to the Settings app.
2. Click on System, then choose About phone.
3. Click on Status and look for an IMEI, MEID, or ESN number.

If your phone has an IMEI number, it’s GSM. If you see a MEID or ESN number, it’s CDMA.

Your phone supports both technologies if you see an IMEI and a MEID or ESN number.

With support for 2G and 3G networks, CDMA and GSM technologies have long been used extensively for voice and data communication.

However, introducing new network infrastructure, such as 5G networks, has significantly diminished the relevance of CDMA and GSM.

In addition, 4G and 5G networks transmit data faster and with greater bandwidth efficiency than 2G and 3G networks using the same radio frequencies.