Which Technology is Better: GSM or CDMA ?

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What is CDMA ?

CDMA stands for Code Division Multiple Access.The CDMA came into existence in 2G and 3G generation.It is the protocol of wireless communication.

It is based on the spread spectrum technology and makes optimal use of the available bandwidth.

Since it uses the spread spectrum technology. It allows each user to transmit the data over the entire frequency spectrum at any time.

Whenever a call made by CDMA network then it take some time but not signal loss during the call. CDMA sim we can used only for CDMA mobile .there are some mobile we can use only CDMA network we can’t insert any sim .

What is GSM ?

GSM stands for Global System for Mobile communication. It is a standard developed by European Telecommunication Standards Institute (ETSI) to describe protocols for second generation (2G) digital cellular networks. It was a replacement for the first generation (1G) cellular networks. The idea of developing GSM originated from a cell-based mobile radio system at the Bell Laboratories in the early 1970s.

GSM is an open, digital cellular radio network operating in over 200 countries worldwide. GSM uses narrow band time division multiple access (TDMA) technology.

It covers almost complete Western Europe and growing in America and Asia. It is not only used for voice calls, it can also be used for data computing and sending text messages. A user can connect his GSM-enabled phone with his laptop to send or receive e-mails, faxes, browse internet, check security etc.

Calling Procedure of GSM Network

when dial a fix number firstly call goes to the PSTN .PSTN check the mobile state are good or not if state is good then its pass through gateway to HLR.HLR have all details of caller so its check network are properly working or not ,balance are in the mobile or not and all other information check then further send to the VLR .VLR send to the local network /AREA. IF call doing in another state then VLR send to Gateway MSRN(Mobile station Roaming number)and then call send to the particular number which is out of state.

Suppose if we are calling in local inside the state then MSISDN pass the call to local people

Difference Between GSM and CDMA

Technology Used

The GSM is based on the wedge spectrum technology, also known as a carrier. This carrier is split into various time slots on the basis of TDMA technology, and each time slots are assigned to each user. Due to this, until one outgoing call is finished, no other user can access that slot. It uses FDMA to provide multiuser access by dividing the user frequencies.

While CDMA uses the spread spectrum technology and hence it makes optimal use of the available bandwidth. It enables each user to transfer the data over the entire frequency spectrum at any time.

SIM Cards

SIM is a smart card that contains the user identification information to identify the subscriber on a telephony device. In a GSM-based phone, a SIM card is required to make the data or call transmission.

On the other hand, CDMA based devices do not require a SIM card; instead, it uses ESN (Electronic Serial Number). Since it does not use a SIM card, hence changing a device from another is difficult and required a proper procedure

Spectrum frequencies

The GSM works on the frequency spectrum ranging from 850 MHz to 1900 MHz,

The CDMA also works on the frequency spectrum ranging from 850 MHz to 1900 MHz.

Data Transfer Rate

The data transfer rate is high in CDMA compared to GSM technology.

In CDMA, EVDO data transfer technology is used, which provides a maximum download speed of 2 Mbps.

While GSM uses EDGE data transfer technology that provides a maximum download speed of 384 Kbps, which is much slower than CDMA.3.6Mbps in CDMA.


The CDMA provides more security as compared to GSM technology because it has inbuilt encryption and uses the spread spectrum for data transmission.

In CDMA, the signal detection is much difficult than in GSM. Hence it is more secure.

So these are some differences about GSM and CDMA technology.

Both GSM and CDMA have their own importance and depends on how both technologies are being used. Approximately 80% of the world uses GSM because its has more benefit than CDMA. CDMA is used mostly in the US and somewhere in Canada and Japan.



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Harshit Gupta is a Software Consultant at knoldus Inc having few year experience in DevOps . He always eager to learn new technology and helping to others .