What is a difference between CDMA & GSM mobile phones?

Question

Which one is better & why?
Please explain in simple language

Answer 1

GSM is your normal everyday sim card and CDMA doesn't have a sim.
CDMA gets way more network coverage, I think it uses the satellites.
I know that CDMA can communicate to phone network towers in say a 5km radius wheras GSM can only communicate in a 2km radius. (I hope all this is making sense!!)
So say the closest tower was 1.8km away and it wasn't working for soome reason then the GSM wouldn't get service but the CDMA could get service from the next tower.
I think CDMA is better only because at my house I have a GSM and my husband has a CDMA, he can get service - I can't! He can get service nearly anywhere. His boat ran out of petrol and his radio was broken so he called the coastguard on his CDMA mobile. (He was in the middle of the ocean.) Also on his phone you can put a memory card like the one in your digital camera so he can store heaps and heaps of photos, videos, music, etc. wheras mine sometimes won't even hold one!

Answer 2

GSM is a network used by Cingular, T-Mobile, and all the wireless services that use the SIM cards in their phones.

CDMA is used by Verizon and Sprint, and the way the signal is sent, (a whole bunch of tech stuff), the data transfer rate for CDMA networks is greater. Thats why Sprint and Verizon Mobile broadband have higher rates than both Cingular and T-mobile.

In my opinion, CDMA is better if you live in the USA and that's all where you'll use your phone. Verizon utilizes CDMA, and i've had verizon for 4 years, and rarely, if ever had a dropped call. And I've moved around through 3 different states in that time.

GSM is better if you're going to use your phone overseas, because the GSM type network is used all over the world.

Answer 3

One major difference between CDMA and GSM is that the GSM phone account information is carried in the SIM card, which can be removed from the phone and placed in any other GSM phone compatible with your carrier. With CDMA, if you want to change phones, you have to go through your carrier.

With GSM, you can buy an unlocked phone, put in your SIM card, and you're good to go. The only downside is that unlocked phones are not really supported by anyone, even the factory unlocked phones, particularly if, for example, you buy an unlocked phone that was intended for use in France and use it instead in the US. Motorola will disavow the warranty, claiming a violation of their usage restrictions.

Answer 4

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Answer 5

CDMA is the American way, and GSM is used everywhere else. Of course, CDMA is better.
When the cell phone is transmitting to the base station it is modulating the carrier, that is, its changing the sine wave it is sending. CDMA changes the amplitude and the phase of the carrier wave, GSM just changes the phase and leaves the amplitude constant. The result is that GSM is more spectrally efficient and much easier to design, there are fewer problems with GSM because it is straightforward. CDMA on the other hand allows for much more data to be sent, 3 or 4 times as much data in the same time period and is more difficult to engineer correctly. And, because everyone wants to send their camera pictures, we use CDMA.

Answer 6

Code division multiple access (CDMA) is a form of multiplexing (not a modulation scheme) and a method of multiple access that does not divide up the channel by time (as in TDMA), or frequency (as in FDMA), but instead encodes data with a special code associated with each channel and uses the constructive interference properties of the special codes to perform the multiplexing. CDMA also refers to digital cellular telephony systems that make use of this multiple access scheme, such as those pioneered by Qualcomm, and W-CDMA by the International Telecommunication Union or ITU.

CDMA has since been used in many communications systems, including the Global Positioning System (GPS) and in the OmniTRACS satellite system for transportation logistics.




GSM




- GSM (Global System for Mobile communication) is a digital mobile telephony system that is widely used in Europe and other parts of the world. GSM uses a variation of time division multiple access (TDMA) and is the most widely used of the three digital wireless telephony technologies (TDMA, GSM, and CDMA). GSM digitizes and compresses 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 MHz or 1800 MHz frequency band.

Answer 7

Code division multiple access (CDMA) is a form of multiplexing (not a modulation scheme) and a method of multiple access that does not divide up the channel by time (as in TDMA), or frequency (as in FDMA), but instead encodes data with a special code associated with each channel and uses the constructive interference properties of the special codes to perform the multiplexing. CDMA also refers to digital cellular telephony systems that make use of this multiple access scheme, such as those pioneered by Qualcomm, and W-CDMA by the International Telecommunication Union or ITU.

CDMA has since been used in many communications systems, including the Global Positioning System (GPS) and in the OmniTRACS satellite system for transportation logistics.

The Global System for Mobile Communications, GSM (original acronym: Groupe Spécial Mobile) is the most popular standard for mobile phones in the world. GSM service is used by over 2 billion people across more than 212 countries and territories.
The ubiquity of the GSM standard makes international roaming very common between mobile phone operators, enabling subscribers to use their phones in many parts of the world. GSM differs significantly from its predecessors in that both signaling and speech channels are Digital call quality, which means that it is considered a second generation (2G) mobile phone system. This fact has also meant that data communication was built into the system from very early on. GSM is an open standard which is currently developed by the 3rd Generation Partnership Project (3GPP).
From the point of view of the consumer, the key advantage of GSM systems has been higher digital voice quality and low cost alternatives to making calls such as text messaging. The advantage for network operators has been the ability to deploy equipment from different vendors because the open standard allows easy inter-operability. Like other cellular standards GSM allows network operators to offer roaming services which mean subscribers can use their phones all over the world.

As the GSM standard continued to develop, it retained backward compatibility with the original GSM phones; for example, packet data capabilities were added in the Release '97 version of the standard, by means of GPRS. Higher speed data transmission has also been introduced with EDGE in the Release '99 version of the standard.

Answer 8

What difference does it make if I use a CDMA, GSM or TDMA cell phone?
http://cellphones.about.com/od/thecellularfaq/f/cf_technologies.htm

Which Technology is Better: GSM or CDMA?
http://www.hardwaresecrets.com/article/151

What is the Difference Between GSM and CDMA?
http://www.wisegeek.com/what-is-the-difference-between-gsm-and-cdma.htm