Let me put my points in a vis-a-vis manner.
- First of all GSM (Groupe Spécial Mobile) now commonly known as Global System for Mobile communications, was started in Europe to study and develop a pan-European public land mobile system.
Their main criteria was:
Good subjective speech quality
Low terminal and service cost
Support for international roaming
Ability to support handheld terminals
Support for range of new services and facilities
Spectral efficiency
ISDN compatibility.
# The first CDMA (Code Division Multiple Access) networks were commercially launched in 1995, and provided roughly 10 times more capacity than analog networks - far more than TDMA or GSM. Qualcomm, holds the licenses and is responsible for the development of its technology.
Their main features were:
supporting more traffic
benefits to carriers and consumers
better voice quality
broader coverage
stronger security
- GSM uses what’s known as ’’time division multiple access’’
(TDMA), which crams less data into the spectrum. GSM digitizes and compresses voice data, then sends it down a channel with two other streams of user data, each in its own time slot. It operates at either the 900, 1800 or 1, 900MHz frequency bands.
# CDMA is a ’’spread spectrum’’ technology, allowing many users to occupy the same time and frequency allocations in a given band/space. As its name implies, CDMA assigns unique codes to each communication to differentiate it from others in the same spectrum. In a world of finite spectrum resources, CDMA enables many more people to share the airwaves at the same time than do alternative technologies.
- GSM technology is in use by more than one in ten of the world’s population and it is estimated that at the end of 2002 there were 787 million GSM subscribers across the 190 countries of the world.
# CDMA has become the fastest-growing of all wireless
technologies, with over 100 million subscribers worldwide.
- Today’s second-generation GSM networks deliver high quality and secure mobile voice and data services (such as SMS/Text Messaging) with full roaming capabilities across the world.
# CDMA phones currently use a wider band than what was allotted to GSM. Hence, applications which are bandwidth-hungry, like video or music can be more easily handled by CDMA. The current generation of GSM is called 2G. Faster versions like 2.5G or 3G (for 3rd generation) will overcome the bandwidth problems and offer multimedia capability as good as CDMA.
- At present in India, we can simply change the SIM of a
particular service provider, Orange, BPL, Airtel etc. if we dont like their service.
# At present in India, Tata, Reliance or BSNL use the same CDMA technology and all such sets will be interchangeable. If you dont like the service from one provider, you can switch to another using the same handset.
Finally, if you ask my opinion, I use a GSM handset, and feel it is a better choice, but sticking to my optimistic view about CDMA Technology, I feel their developers have tremendous potential and who knows, it could be a dominant technology in the future.