Originally Posted by
Paul94544 
Advantages of CDMA include:
Increased cellular communications security.
Simultaneous conversations.
Increased efficiency, meaning that the carrier can serve more subscribers.
Smaller phones.
Low power requirements and little cell-to-cell coordination needed by operators.
Extended reach - beneficial to rural users situated far from cells.
Disadvantages of CDMA include:
Due to its proprietary nature, all of CDMA's flaws are not known to the engineering community.
CDMA is relatively new, and the network is not as mature as GSM.
CDMA cannot offer international roaming, a large GSM advantage.
The Euro-Asian Alternative: GSM
Analysts consider Qualcomm's major competitive disadvantage to be its lack of access to the European market now controlled by Global System for Mobile communications (GSM). The wireless world is now divided into GSM (much of Western Europe) and CDMA (North America and parts of Asia).
Bad timing may have prevented the evolution of one, single global wireless standard. Just two years before CDMA's 1995 introduction in Hong Kong, European carriers and manufacturers chose to support the first available digital technology - Time Division Multiple Access (TDMA). GSM uses TDMA as its core technology. Therefore, since the majority of wireless users are in Europe and Asia, GSM has taken the worldwide lead as the technology of choice.
Mobile Handset manufacturers ultimately split into two camps, as Motorola, Lucent, and Nextel chose CDMA, and Nokia and Ericsson eventually pushed these companies out and became the dominant GSM players.
Advantages of GSM:
GSM is already used worldwide with over 450 million subscribers.
International roaming permits subscribers to use one phone throughout Western Europe. CDMA will work in Asia, but not France, Germany, the U.K. and other popular European destinations.
GSM is mature, having started in the mid-80s. This maturity means a more stable network with robust features. CDMA is still building its network.
GSM's maturity means engineers cut their teeth on the technology, creating an unconscious preference.
The availability of Subscriber Identity Modules, which are smart cards that provide secure data encryption give GSM m-commerce advantages.
In brief, GSM is a "more elegant way to upgrade to 3G," says Strategis Group senior wireless analyst Adam Guy.
Disadvantages of GSM:
Lack of access to burgeoning American market.
Today, the battle between CDMA and GSM is muddled. Where at one point Europe clearly favored GSM and North America, CDMA, the distinct advantage of one over the other has blurred as major carriers like AT&T Wireless begin to support GSM, and recent trials even showed compatibility between the two technologies.
GSM still holds the upper hand however. There's the numerical advantage for one thing: 456 million GSM users versus CDMA's 82 million.
