GSM vs CDMA

GSM= Global System for Mobile Communications

CDMA= Code Division Multiple Access

These are two main competing network technologies in the cellular service world. What exactly is the difference between these two technologies might be worth knowing, if you are in a position to choose either one of these services for your needs. Some of the major features of these technologies can be compared as follows.

The core difference between GSM and CDMA has to do with the way the data is converted into the radio waves which the cellphone broadcasts and receives.GSM divides the frequency bands into multiple channels so that more than one user can place a call through a tower at the same time; CDMA networks layer digitized calls over one another, and unpack them on the back end with sequence codes.

CDMA and GSM are both Radio technologies and need a mobile Phone which is used as an Antenna to recieve these Radio Signals. Both the technologies work on different frequency range and has different modulation schemes. Thus the mobile phones for both are different.However a 3G mobile can serve for both GSM and CDMA radio signals as 3G technology is a combination of both GSM and CDMA (WCDMA).

SIM (Subcriber Idendity Module) is used to provide Credential for network authorization. As both GSM and CDMA technologies have different Authorization functions and parameters, their SIMs are different as well.Furthermore, in CDMA technology the SIM is often called as RUIM (Removable User Idendity Module). However, not all the companies provide SIM cards for CDMA technology based services. In GSM, there is the chance of losing all your data when the SIM is lost if you have not stored in phone's memory.

2G GSM networks can offer better coverage in mountainous terrain, as they utilize taller cell towers. Additionally, it is possible for GSM (and UMTS) phones to send and receive data packets while making a call, which most CDMA networks still don't support.

A CDMA-only phone is only able to roam on other CDMA networks, which is a huge disadvantage when travelling. However this limitation does not effect GSM carriers. People with a tri-band GSM phone can use it in almost every part of the world.

Although the Call Costs are becoming cheaper every other day for GSM, the lowest call charges are offered by CDMA as yet. In addition, roaming call costs in GSM continue to be higher than CDMA. As of now the call quality of CDMA is better than GSM too.

Call quality is comparatively secure & good in GSM than CDMA. 

Further, more and more value-added services like GPRS, EDGE etc are getting added to GSM which makes it all the more popular. In addition, CDMA services have not yet got the facility for web based services like messenger, downloading ringtones etc from websites.

 

When it comes to power consumption, it is less in GSM handsets as compared to CDMA handsets.

But, GSM phones are not full proof & can be tampered with. Moreover, there is no availability of a variety of handsets in CDMA as in GSM for customers and they are incompatible with GSM handsets as well. GSM services offer a variety of handsets & service providers are available to choose from.