What are the differences between GSM and CDMA phones?

Question

I have been wondering about what distinguishes the two, GSM and CDMA mobile phones.

Can someone shed more light on this please?

Answer 1

GSM and CDMA are competing wireless technologies with GSM enjoying about an 82% market share globally.

GSM (Global System for Mobile communications is a specification of an entire wireless network infrastructure

CDMA (Code Division Multiple Access) relates only to the air interface — the radio portion of the technology.Code division multiple access describes a communication channel access principle that employs spread-spectrum technology and a special coding scheme (where each transmitter is assigned a code). CDMA also refers to digital cellular telephony systems that use this multiple access scheme,

Comparison

CDMA                   -             Code Division Multiple Access
Storage Type:                         Internal Memory
Data transfer:                         EVDO/3G/4G/LTE
Network:                                There is one physical channel and a special code for every device in the coverage network. Using this code, the signal of the device is multiplexed, and the same physical channel is used to send the signal
International roaming:      Less Accessible
Frequency band:              Single(850 MHz)
Network service:               Handset specific
    
    GSM           -             Global System for Mobile communication
Storage Type:                   SIM (subscriber identity module) Card
Data transfer:                    GPRS/E/3G/4G/LTE
Network:                           Every cell has a corresponding network tower, which serves the mobile phones in that cellular area.
International roaming:       Most Accessible
Frequency band:              Multiple(850/900/1800/1900 MHz)
Network service:               SIM specific. User has option to select handset of his choice.

Comments

Thank you hey.

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This means if i have a mobile phone which is 3G enabled then i can use any one of the sim/line

Answer 2

CDMA and GSM are Radio technologies and mobile Phone is just an Antenna to receive these Radio Signals. Since both the technologies work on different frequency range and has different modulation shemes therfore the mobile phones for both are different.
Apart from this 3G tehchnology which is combination of both GSM and CDMA (WCDMA) is compatible with both GSM and CDMA. So a 3G mobile can serve for both GSM and CDMA radio signals.
SIM (Subcriber Idendity Module) is consists of Credential for network authorization. Since Both GSM and CDMA technologies has different Authorization functions and parameters hence both SIMs are different. Note: In CDMA technology SIM is often called as RUIM (Removable User Idendity Module).
CDMA uses Different Frequencies than GSM. CDMA also does not require a SIM card eg you can use Powertel dongle without a sim card..
Now some companies do provide SIM cards for CDMA connections also, such asAfricom
In Zimbabwe CDMA carriers are Africom and Powertel while GSM carriers here in the Zimbabwe are Telecel, Econet, Netone.

Comments

So how do you tell which is gsm and cdma when it comes to iphones?

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Thank you Castro

Answer 3

Difference between GSM and CDMA phones are
1.Global System for Mobile communications(GSM) Phone Number Binding With SIM card,Code Division Multiple Access(CDMA) Phone Number Binding With mobile handset.
2.GSM data is stored in SIM card and the CDMA data is stored in Phone’s internal memory.
3.You are free to buy any GSM handset from market.The CDMA Handset is changed through service provider only.4.Data Transfer Technologies of GSM is EDGE/HSDPA and CDMA is EVDO/3G/4G/LTE.
5.Transfer Speed of GSM is A wee bit slower,but catching up fast and CDMA is .
6.International Roaming of GSM is Very good and we can use the same handset in abroad by getting an another local sim card in abroad.For this we may need to unlock our mobile by getting the unlocking service by a relevant software or by an online service provider like  http://www.theunlockspot.com/supported-phones/rs10wp7/.The CDMA is not available all over the globe (so if you fly around the world, GSM could be a better choice for you)