Before discussing and differentiating these two technologies we should know their separate meanings.
Global System for Mobile Communication and popularly known as GSM. It is copyrighted term which refers to the use of Time-Division Multiple Access Technology known as TDMA. This technology is now globally available over 100 countries and is considered as the standard for communication especially in Asia and Europe. It functions on four distinct frequencies i.e. 900MHz and 1,800MHz bands in Europe and Asia while in North America and Latin America at 850 MHz and 1,900 MHz bands. Eight simultaneous calls on the same radio frequency is possible with GSM. It uses “narrowband” TDMA which allows digital transmission between a cell phone and a base station. It is termed as narrowband because the frequency band, with TDMA is divided into numerous channels which are then piled together into a single stream. One plus point is that more than one caller can share the same channel at the same time.
Code Division Multiple Access abbreviated as CDMA is an entirely different technology. It particularly implicates multiplexing technology and technique used is for digital communication. After the channel is digitized, it spreads data out over the channel. It presents greater security as compared to GSM/TDMA as it is more efficient in analog transmission, has increasing battery capacity, greater frequency reuse and rate of dropped calls is improved. Because of its much reliable features, the experts favor its development across the globe. It is mostly found in United States, Canada and North and South Korea. The original CDMA is now called as CDMA one.
The basic difference between the two i.e. GSM and CDMA is regarding their frequency bands. In case of GSM, the end user doesn’t have access to the entire frequency band whereas in case of CDMA the end user can access the entire frequency. So we can say that in CDMA frequencies re-use factor is 1. It’s a debate that either GSM or CDMA is superior to the other but if we take account the users which need to the point information to attain the services and make choice out of it, following consideration will may help them.
It is consider being most important factor that is you find cellular services wherever you are but CDMA and GSM are the only carriers that provide cellular services everywhere. In this case there will not be any difference but the customers still have a choice.
Speed in Data Transferring:
People who use their phone more than making calls, it means use it as a streaming video device or email devices, speed is the most vital factor and in this area CDMA is said to be traditionally faster than GSM though both of these technologies claim 3rd generation standards. So people have choice in this case.
Subscriber Identity Module (SIM) Cards:
In United States, SIM cards are used by GSM only. Without carrier intervention, the removable SIM cards enable cell phone to get instantly activated, upgraded and swapped. GSM takes over CDMA in the case that the phones which are easily get enabled with card and are also useable with any of the present carriers but in case of CDMA phone, the old phone has to be deactivated by the carrier and then active the new one. Hence, the old phone turns out to be useless.
GSM carriers are having roaming contracts with other GSM carriers which enable wider and reliable coverage even in rural areas and the customers also do not have to bear the charges whereas charges, in case of CDMA networks, are significantly higher and they also do not cover rural areas but they may contract with GSM cells regarding roaming in rural areas.