Many of those people who are planning to buy a mobile phone think hard whether to go for a CDMA phone or a GSM phone. The question is pretty understandable and a good one too. Most people do not understand the difference between CDMA and GSM phones. Both these technologies have been in market for quite some time with a number of service providers offering attractive packages.
First let's begin by knowing the full forms of these acronyms:
- Full form of CDMA is Code Division Multiple Access
- Full form of GSM is Global System for Mobile communications, but originally from Groupe Spécial Mobile
- Full form of SIM is Subscriber Identity Module
Although, globally GSM is more used but in the United States of America CDMA is more popular than GSM. Some of the CDMA providers in various countries are: Verizon (USA), Bell Mobility (USA) and MTS Mobility (USA), Reliance (India) and BSNL (India) etc. Worldwide availability of GSM makes it more accessible in terms of international roaming. Some of the GSM providers around the globe are: Cell C (South Africa), Idea (India), Vodafone (multiple countries), AT&T (USA) and T-Mobile (UK) etc.
First of all, we need to understand that CDMA and GSM are not really technologies but the industry standards / specifications for wireless communication. At present, GSM (short form for Global System for Mobile communications, but originally from Groupe Spécial Mobile) specification holds the lion’s share in market. With more than 80% of world market share, usage of GSM is miles ahead of CDMA. The acronym CDMA stands for Code Division Multiple Access.
In practical terms, the most important difference between these two is that the CDMA is a handset based standard. This means that you can not use just any mobile phone –you need to go to market and buy a CDMA phone from a carrier who providers CDMA service. So it is like that your phone number is bound to a handset. Whereas in case of GSM, only SIM card is bound to the phone number and, as a result, you are free to change your mobile phone anytime –you just need to remove SIM card from old phone and insert it in the new phone.
Now let’s get into more technical details. Every CDMA mobile phone has a specific code associated with it. One blanket network covers all the CDMA devices within its coverage area and the device is identified by the associated code. In case of GSM mobile network, each SIM is served by a cell tower whose area the SIM card arrives in. Therefore, the SIM card’s serving tower keeps changing as your drive through a city. This mechanism requires installation of an appropriate number of cellular towers to cover a big area (as that of a city).
Let's now do a tabular and concise comparison among these two communication standards.
|Acronym Full Form||Global System for Mobile communications||Code Division Multiple Access|
|Phone Number Binding||With SIM card||With mobile handset|
|Data Storage||Data is stored in SIM card||Phone's internal memory|
|Phone Change||You're free to buy any handset from market||Handset is changed through service provider|
|Data Transfer Technologies||EDGE/HSDPA||EVDO/3G/4G/LTE|
|Transfer Speed||A wee bit slower -but catching up fast||Faster|
|Battery Consumption||Consume less power||Consume more power|
|Availability||Covers almost the entire globe||Mainly in USA and parts of Asia|
|Market Share||Approx 80%||Approx 20%|
|International Roaming||Very good||CDMA is not available all over the globe (so if you fly around the world, GSM could be a better choice for you)|
|Frequency Band||From 850 MHz to 1900 MHz||Only 850 MHz|
I hope now your concept of of a CDMA and GSM phone is clear. CDMA is phasing out of the world with GSM taken over most of the market. However, you still get CDMA mobile services. In India, for example, Reliance is still providing CDMA service.
Please let me know if you have any questions about this topic. Thank you for using TechWelkin.