advantages and disadvantages of GSM

GSM is still dominant in the mobile market, shares 80% worldwide market, in spite of fast development of CDMA. There is a comparison that gives me vivid impression. Imagine a cocktail party, where couples are talking to each other in a single room. The room represents the available bandwidth. In GSM, a speaker takes turns talking to a listener. The speaker talks for a short time and then stops to let another pair talk. There is never more than one speaker talking in the room, no one has to worry about two conversations mixing. In CDMA, any speaker can talk at any time; however each uses a different language. Each listener can only understand the language of their partner. As more and more couples talk, the background noise (representing the noise floor) gets louder, but because of the difference in languages, conversations do not mix.

There are a lot of advantages of GSM:
GSM is mature; this maturity means a more stable network with robust features;
Less signal deterioration inside buildings;
Ability to use repeaters;
Talktime is generally higher in GSM phones due to the pulse nature of transmission.;
GSM covers virtually all parts of the world so international roaming is not a problem;
The much bigger number of subscribers globally creates a better network effect for GSM handset makers, carriers and end users.

On the other hand, the disadvantages of GSM have been noticed:
Pulse nature of TDMA transmission used in 2G interferes with some electronics, especially certain audio amplifiers. 3G uses W-CDMA now.
Intellectual property is concentrated among a few industry participants, creating barriers to entry for new entrants and limiting competition among phone manufacturers.
GSM has a fixed maximum cell site range of 35 km, which is imposed by technical limitations.

When I look at 3G, I still can’t fully understand the advantages of 3G. However, some issues debated by 3G providers and users attract me, such as Expensive input fees for the 3G service licenses, Numerous differences in the licensing terms, Large amount of debt currently sustained by many telecommunication companies, Lack of member state support for financially troubled operators, Expense of 3G phones and so on.