What Is The Difference Between GSM And CDMA

Your main concerns are coverage, quality, customer service, pricing, and other considerations when it comes to mobile network providers. However, in the United States, you must choose between a GSM and a CDMA network when selecting a network carrier. You’ve undoubtedly come across these words before, whether buying a phone, joining a network, or moving carriers. This article aims to look at what is the difference between GSM and CDMA and their significance to consumers.

For a long time, cellular mobile services have been utilized worldwide, and they are still evolving daily. Different communication services have arisen due to these services, including CDMA and GSM. The two most widely used mobile communication technology protocols are CDMA and GSM. Both technologies convert data from cell phones booster into radio waves.

However, these technologies differ in how calls and data are transmitted through a network. One of the most significant distinctions between CDMA and GSM is that GSM uses SIM cards to link a phone to its network, whereas CDMA uses ESNs (Electronic Serial Numbers) instead. We’ll look at what GSM and CDMA are and how they differ in this article. 

What is GSM technology?

Global System for Mobile Communication or GSM stands for a digital mobile communication standard that allows you to send and receive data and speech signals across a network. The standard also referred to as the second-generation standard for mobile networks or communications, uses a wedge spectrum to operate.

For separating users and cells and delivering signals, GSM uses TDMA (Time Division Multiple Access) and FDMA (Frequency Division Multiple Access) variations. GSM converts our voice into digital data assigned a channel and a time slot. On the other hand, the receiver merely listens to the designated time slot while the call is stitched together. This process occurs in a short time, and the receiver is unaware of the “break,” or temporal division. 

900MHz, 1800MHz, and 1900MHz are the three radio frequencies used by GSM. The Original GSM system uses the 900MHz band frequency, whereas the 1800 MHz band frequency provides additional support for growing client numbers. In the United States, the 1900MHz band is only used there.

The GSM users were the first to use the service Short Message System (SMS). SMS allows people to connect using text messages over a network. 

The advantages of this radio technology are;

  • We can have low-cost mobile phones and base stations thanks to GSM technology
  • It increases the efficiency of the spectrum
  • GSM provides high-quality data and voice signals
  •  Compatible with ISDN (Integrated Services Digital Network)

What is CDMA technology?

Code Division Multiple Access (CDMA) is a radio telecommunications protocol similar to GSM. CDMA is a wireless communication system that first appeared in the 2G and 3G generations. On the other hand, CDMA hasn’t had the same global adoption as GSM due to its proprietary nature, with less than 18% of global networks employing the technology.

It utilizes spread spectrum technology to get the most out of the bandwidth. Because it uses spread spectrum technology, each user can send data over the whole frequency spectrum at any moment. Due to its spread spectrum feature, CDMA is one of the most secure ways of communication.

CDMA networks overlay digitalized calls on top of one another, distinguishing them with unique codes. The data for each call gets encoded with a separate key and sends the calls simultaneously. Each receiver has its unique key, which divides the combined signal into individual calls. 

It’s utilized in UHF (ultra-high-frequency) cellular systems with 800 to 1900 MHz frequencies.

The advantages of CDMA include;

  • It maximizes the efficiency of a specific frequency spectrum
  • The number of Users is unrestricted. 
  • It allows for resource allocation flexibility.
  • It works with other cellular technologies, allowing for countrywide roaming.

 What is the difference between GSM and CDMA? 

what is the difference between gsm and cdma

Both are multiple access protocols, which means you can route several calls through a single tower. However, the primary difference is how they turn your data into radio waves that your phone transmits and receives. Of course, other practical issues are more important to us as consumers, which we state below:  

i) Technology used

The wedge spectrum technology, commonly known as a carrier, is the foundation of the GSM. Based on TDMA technology, this carrier gets divided into multiple time slots, each given to a different user.

As a result, no other phone user can access that slot until you complete an outbound call. By dividing the user frequencies, it employs FDMA to provide multiuser access.

On the other hand, CDMA employs spread-spectrum technology to maximize available bandwidth. It allows each user to transfer data at any moment throughout the entire frequency range. 

ii) SIM Cards

A SIM card is necessary to send data or make calls on a GSM-based phone. With their saved data, you can transfer these cards from one mobile phone to another.

CDMA-based phones do not need a SIM card; instead, they use ESN (Electronic Serial Number). Because they do not use a SIM card, switching from one device to another is complex and necessitates following a specific procedure. 

iii) Spectrum frequencies used

GSM uses a frequency range of 900 MHz to 1900 MHz, while CDMA uses 800 MHz to 1900 MHz. 

iv) Flexibility

Compared to CDMA, the GSM standard is more versatile because you can replace the SIM card with any device. On the other hand, you can only use CDMA phones if the ESN is registered in its database.

If a CDMA phone stops operating, we must purchase a new phone. However, if a SIM phone ceases working, we can replace it with another SIM rather than purchasing a new phone.

v) International roaming and reach

Compared to CDMA technology, many users utilize GSM technology. In contrast to CDMA, GSM gets used by over 80% of mobile networks in 210 countries. The CDMA-based devices are commonly used in the US, Canada, and Japan.

Because GSM is used and accepted worldwide, it has roaming capabilities, but CDMA has limited roaming capabilities due to its less widespread use. 

vi) Radio Exposure

Compared to CDMA phones, GSM phones expose users to 28 times more radiation. GSM phones continuously send wave pulses, whereas CDMA phones do not. 

vii) Transmission rate

GSM uses GPRS, which has a lesser bandwidth and transmits data at a slower rate. On the other hand, CDMA employs EVDO, which offers greater data bandwidth and a faster data transmission rate. 

viii) Security

CDMA technology is more secure than GSM since it has built-in encryption and leverages the spread spectrum for data delivery. Signal detection in CDMA is substantially more challenging than in GSM. As a result, it is more secure. 

How can you tell whether your phone is GSM or CDMA? 

Check the below criteria to see if your phone is GSM or CDMA-based: 

i) Check from your Phone Settings:

  • For iPhone users: Check the MEID, ESN, or IMEI number near the bottom of the Settings- General-About. 
  • For Android users: Go to System then about the phone in the Settings. Check for the IMEI, ESN, or MEID number by clicking on Status. 

If you notice the MEID or ESN number, in either case, your phone is CDMA. Your device is a GSM-based phone if you see the IMEI number. If you see both options, your device is compatible with both technologies. 

ii) Check for SIM card Slot on the device

As previously stated, GSM phones utilize SIM cards, whereas CDMA phones do not. As a result, you can check whether your phone has a SIM slot or not. Due to the widespread use of 4G LTE technology, most CDMA smartphones now use SIM cards, making this method of checking less valuable. 

What is the future of GSM and CDMA technologies?

With the introduction of 4G and the widespread adoption of LTE and LTE-Advanced as the global standard by most network carriers, the dispute between GSM and CDMA is becoming increasingly irrelevant. You may have noticed that current CDMA handsets also contain SIM card slots, allowing you to use the network’s 4G LTE capabilities. 

With the transition to 5G, the distinction between GSM and CDMA is becoming less critical as voice call technologies get progressively migrated to data network brands. Today, the argument is merely a consideration because 2G and 3G networks get still employed as the backbone of network voice technologies.

These bands have repurposed, and networks are no longer using this outdated voice technology. AT&T, for example, turned off its 2G GSM network, while Verizon turned off its 2G and 3G CDMA networks. 

Bottom line

Both GSM and CDMA have their value, depending on how you use them. GSM is utilized by about 80% of the world, while CDMA is used in the United States, Canada, and Japan. These radio systems are becoming obsolete with the introduction of 4G and 5G technology.

For example, AT&T and Verizon have shut down their 2G GSM and 2G and 3G CMDA networks. Many CDMA phones now support GSM technology for international roaming, worth noting.