CDMA or GSM, does it matters?

Choosing between CDMA and GSM? We'll help you to decide it with infographics and charts! 

When pondering about mobile networks, how they work and who the best providers of the service really are, it is inevitable to start thinking about coverage, price, quality and support given.  

These are acronyms that have long since become familiar but what do they really mean and how does the choice of one or the other affect your entire mobile experience?

CDMA and GSM are two different cellular standards that allow and facilitate communication on a global level but in ways that differ due to the fact that each one converts the data coming in and going out differently. 


Stands for Code Division Multiple Access.

This technology was developed during WWII by The Allied Forces as a way to avoid the jamming of radio signals by the Nazi. It grants access to the complete band spectrum which allows the possibility of more users being connected at any given time.

Each user’s conversation is encoded individually thanks to a pseudo-randomized digital sequence that allows the voice data to remain protected and filtered at the same time, meaning that only the parties involved in the call shall receive its data making it a safe communication route.

Digitalized calls, after being assigned unique codes to enable differentiation, are layered one over the other thanks to CDMA networks. The data pertaining to every call is then encoded with the use of a different key, allowing it to be transmitted. 

  • CDMA was patented by Qualcomm and then served as the basis for the development of the CDMA2000 and WCDMA standards for 3G.

  • This technology, though quite functional, has not been privy to the international acceptance, adoption and use that GSM has had.

  • This is evidenced by the fact that fewer than 18% of global networks are using CDMA. It is mostly found in USA, South Korea, and Russia. 

  • Mobile phones that operate with this technology do not require SIM cards.

Their use and functionality are limited to the carrier’s network which means that should you want to change providers, you will have to purchase a new phone with a new carrier or different technology. 


The acronym stands for Global System for Mobile Communication.

It is the standard mobile communication system in most parts of the world except USA and Russia.

In fact,

it is available in over 210 countries throughout the world. Networks operating under GSM classification use Time Division Multiple Access.

TDMA assigns a specific time slot to each of multiple conversation streams, modifying their sequence while going from one to the other through very short time frames or intervals.

Information is transmitted by the devices during these intervals and each user is assigned a Subscriber Identification Module or SIM, card that allows the network to identify who is connected  and when. 

In SIM cards lay the core of GSM technology. They contain the most important elements and data that allow communication: network ID, subscription to the service and address book information.

Time slots for phone conversations are assigned thanks to network identification which also informs the services to which the user has subscribed and stores all contact information by means of the address book.

In some cases, when the carrier allows, SIM cards are able to pass information between devices. 

When making a call using GSM, the voice of the caller is converted to digital data and then assigned a time slot or channel for transmission.

The receiver of the call gets to listen to assigned channel whilst the call is being pieced together. All this happens in such rapidity that neither the caller nor the receiver notices the occurrence of any time division.   

GSM functions on four distinct frequency bands:

  • 900 MHz and 1800 MHz is Europe and Asia, and

  • 850 MHz and 1900 MHz in North and South America. 

In 1987, the international GSM Association was founded with the set goal to develop, oversee and expand the standards and regulations of GSM wireless technology.  

You might be wondering: Which is better?

It is not a matter of whether GSM is better or worse than CDMA. Both are globally accepted standards pertaining to cell communication.

The technology used to transmit data during a call does not affect the quality of the call itself; this is determined by the network that the carrier offers. 

There are, however, differences in functioning and essential characteristics that are good to bear in mind when choosing one over the other: 

CDMA phones are forever tied to their carriers making it virtually impossible to be transferred from one network to another.

For example,

if you purchase a phone that subscribers to Sprint’s network, you will not be able to change to Verizon later down the road or vice versa. GSM phones, on the other hand, are not difficult to jailbreak and then transfer to another network when needed thanks to the usage if the SIM card.

There are manufacturers that offer phones designed for multiple GSM networks, allowing them to function appropriately without needing to access a specific carrier making it much easier to remain in contact through your cell phone when traveling abroad since they work in any country that offers compatible GSM networks. 


While GSM is much more popular worldwide, CDMA remains the most sought after network in the US.

The fact that Verizon Wireless, a CDMA network carrier, has the most subscribers in the country is a testament to it to the preference Americans display towards this network. 

market share of wireless subscriptions

A greater number of users are allowed on CDMA which means that their capacity for communication exceeds that of GSM networks. All 3G networks are based on CDMA technology whether they are subscribed to GSM or CDMA carriers. 

International roaming is one of the aces up GSM’s sleeve.

Since it is the most popular network internationally speaking, there is a myriad of plans, services and offers available from carriers and providers in different countries.

It is extremely easy to remain connected when traveling with GSM technology since all you need to do is purchase a local SIM card that you can just insert into your phone for the duration of your stay (provided your device is unlocked, of course). Data connectivity may be limited, though, so just choose wisely.

Customers in the US may wonder which companies offer which type of network. It is really quite simple, as you can see below: 



-          Verizon

-          Sprint

-          AT&T

-          T-Mobile


Your geo-location might influence in your speed: Click the image above


If you are looking to upgrade your phone and perhaps change carriers, knowing the specific features, services, devices and quality of service that a provider offers is way more important and should have greater weight on your decision that whether it is simply CDMA or GSM unless you have a pressing need to select one or the other.

Your preferences, budget, and lifestyle should also be factored into the decision-making process.

The advent of LTE

In recent years, a new network has made its appearance in the world of cell technology and networks.

Long-Term Evolution (LTE) uses an evolved form of GSM using technology that is very similar in nature.  

It has quite promptly become the forerunner where quality is concerned which has made many major cell phone companies switch to its capabilities.

Where LTE is concerned, there is a higher voice quality and all its functions are based on high-speed, 4G data networks making it much speedier in terms of connectivity and navigation.

Apparently, this is where we are headed where cell technology is concerned, so worrying about whether to choose CDMA or GSM won’t matter much in the short term where 4G LTE will more than likely reign supreme.

October 25, 2016 by
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