gsm is global system for mobile communication. it uses fdma 
& tdma.

cdma:-  it stands for code division mutiple access.

gsm is stands for global system for mobile communication. it
use tdma & fdma techniques as access mechanism . in gsm we
devide bandwidth in to time slots for better utilization of
bandwidth.

cdma stands for code devision muliple access it use cdma
techniques as access mechanism . in cdma we allocate a
unique code for every user saparately and allocate bandwidth
to user

GSM and CDMA techniques can be explained with an example 
suppose there are 10 persons in a room and they want to
communicate with each other .How can they communicate?
First method:One persons speaks at one time that means we
have provided a definite time interval to that person.-GSM
Second method :all the peers  speak at a time in a different
language which we call as CDMA

The main difference between GSM and CDMA is: In GSM, the 
entire frequency band is not available to the end-user, 
while in CDMA the entire frequency band is available to the 
end-user. So, the Frequency Re-use factor is 1 in CDMA. 

GSM Works as follows:
---------------------
     The entire frequency band is divided into chunks and 
each such chunk is divided into timeslots and each such 
portion is made available to a user. 

CDMA Works as follows:
-----------------------
    The entire frequency band is available to the user. So, 
in order to differentiate, the transmission from each user 
is "spread" or coded using an unique code given to 
individual user. At the receiving end, the spread 
information is decoded.

GSM is a Global Syatem For Mobile Communication. 

GSM Operates 3 bands, 1) GSM 900 2) GSM 1800 and 3) GSM 
1900. 

GSM 900 & GSM 1800 are used in india, But, GSM 1900 used in 
USA.

GSM and CDMA techniques can be explained with an example,

suppose there are 10 persons in a room and they want to
communicate with each other .How can they communicate?
First method:One persons speaks at one time that means we
have provided a definite time interval to that person.-GSM
Second method :all the peers  speak at a time in a different
language which we call as CDMA

CDMA stands for Code Division Multiple Access and GSM 
stands for Global system for Mobile Communication. 
In CDMA phones the software is integral with the phone 
instrument and in the case of GSM phones it is through the 
SIM Card.

CDMA phone instruments are dedicated to the service 
provider. GSM phone instruments are portable across service 
providers through SIM cards.

gsm is stand by globle system for mobile communication,gsm
frequency band is 900mhz-1800mhz,this is communicate all
rural area in all time,cdma is same frequency band but can
not available in rural area in all time.

gsm is global system for mobile communication . here MS is 
equipped with sim . 
CDMA is a code division multiple access MS is not equipped 
with sim .

hi Vrp
what do u mean by MS ???? is this mobile station ?????

Then there is something wrong in ur ansr

Thanks
AKshay

Email: akshay_bali2001@yahoo.co.in

mobile statio(M.S)=mobile equipmemt(M.E)+ SIM (subscriber 
identity module)


satya_823@yahoo.co.in

GSM: In GSM only 30 or 35 peoples can call at at time in a 
singal carrier but In CDMA apprx 70 peoples can call in a 
singal carrier at a time.

In cellular service there are two main competing network 
technologies: Global System for Mobile Communications (GSM) 
and Code Division Multiple Access (CDMA). Cellular carriers 
including Sprint PCS, Cingular Wireless, Verizon and T-
Mobile use one or the other. Understanding the difference 
between GSM and CDMA will allow you to choose a carrier 
that uses the preferable network technology for your needs.
The GSM Association is an international organization 
founded in 1987, dedicated to providing, developing, and 
overseeing the worldwide wireless standard of GSM. CDMA, a 
proprietary standard designed by Qualcomm in the United 
States, has been the dominant network standard for North 
America and parts of Asia. However, GSM networks continue 
to make inroads in the United States, as CDMA networks make 
progress in other parts of the world. There are camps on 
both sides that firmly believe either GSM or CDMA 
architecture is superior to the other. That said, to the 
non-invested consumer who simply wants bottom line 
information to make a choice, the following considerations 
may be helpful.
Coverage: The most important factor is getting service in 
the areas you will be using your phone. Upon viewing 
competitors' coverage maps you may discover that only GSM 
or CDMA carriers offer cellular service in your area. If 
so, there is no decision to be made, but most people will 
find that they do have a choice.
Data Transfer Speed: With the advent of cellular phones 
doing double and triple duty as streaming video devices, 
podcast receivers and email devices, speed is important to 
those who use the phone for more than making calls. CDMA 
has been traditionally faster than GSM, though both 
technologies continue to rapidly leapfrog along this path. 
Both boast "3G" standards, or 3rd generation technologies.
EVDO, also known as CDMA2000, is CDMA's answer to the need 
for speed with a downstream rate of about 2 megabits per 
second, though some reports suggest real world speeds are 
closer to 300-700 kilobits per second (kbps). This is 
comparable to basic DSL. As of fall 2005, EVDO is in the 
process of being deployed. It is not available everywhere 
and requires a phone that is CDMA2000 ready.
GSM's answer is EDGE (Enhanced Data Rates for GSM 
Evolution), which boasts data rates of up to 384 kbps with 
real world speeds reported closer to 70-140 kbps. With 
added technologies still in the works that include UMTS 
(Universal Mobile Telephone Standard) and HSDPA (High Speed 
Downlink Packet Access), speeds reportedly increase to 
about 275—380 kbps. This technology is also known as W-
CDMA, but is incompatible with CDMA networks. An EDGE-ready 
phone is required.
In the case of EVDO, theoretical high traffic can degrade 
speed and performance, while the EDGE network is more 
susceptible to interference. Both require being within 
close range of a cell to get the best speeds, while 
performance decreases with distance.
Subscriber Identity Module (SIM) cards: In the United 
States only GSM phones use SIM cards. The removable SIM 
card allows phones to be instantly activated, interchanged, 
swapped out and upgraded, all without carrier intervention. 
The SIM itself is tied to the network, rather than the 
actual phone. Phones that are card-enabled can be used with 
any GSM carrier.
The CDMA equivalent, a R-UIM card, is only available in 
parts of Asia but remains on the horizon for the U.S. 
market. CDMA carriers in the U.S. require proprietary 
handsets that are linked to one carrier only and are not 
card-enabled. To upgrade a CDMA phone, the carrier must 
deactivate the old phone then activate the new one. The old 
phone becomes useless.
Roaming: For the most part, both networks have fairly 
concentrated coverage in major cities and along major 
highways. GSM carriers, however, have roaming contracts 
with other GSM carriers, allowing wider coverage of more 
rural areas, generally speaking, often without roaming 
charges to the customer. CDMA networks may not cover rural 
areas as well as GSM carriers, and though they may contract 
with GSM cells for roaming in more rural areas, the charge 
to the customer will generally be significantly higher.
International Roaming: If you need to make calls to other 
countries, a GSM carrier can offer international roaming, 
as GSM networks dominate the world market. If you travel to 
other countries you can even use your GSM cell phone 
abroad, providing it is a quad-band phone 
(850/900/1800/1900 MHz). By purchasing a SIM card with 
minutes and a local number in the country you are visiting, 
you can make calls against the card to save yourself 
international roaming charges from your carrier back home. 
CDMA phones that are not card-enabled do not have this 
capability, however there are several countries that use 
CDMA networks. Check with your CDMA provider for your 
specific requirements.
According CDG.org, CDMA networks support over 270 million 
subscribers worldwide, while GSM.org tallies up their score 
at over 1 billion. As CDMA phones become R-UIM enabled and 
roaming contracts between networks improve, integration of 
the standards might eventually make differences all but 
transparent to the consumer.
The chief GSM carriers in the United States are Cingular 
Wireless, recently merged with AT&T Wireless, and T-Mobile 
USA. Major CDMA carriers are Sprint PCS, Verizon and Virgin 
Mobile. There are also several smaller cellular companies 
on both networks.
Code division multiple access (CDMA) is a form of 
multiplexing and a method of multiple access to a physical 
medium such as a radio channel, where different users use 
the medium at the same time thanks to using different code 
sequences.
A number of terms are used to refer to CDMA 
implementations. The original US standard defined by 
QUALCOMM was known as IS-95, where IS refers to an Interim 
Standard of the US Telecommunications Industry Association. 
IS-95 is often referred to as the second generation (2G) 
cellular, or as cdmaOne (the QUALCOMM brand name). CDMA has 
been submitted for approval as a mobile air interface 
standard to the International Telecommunication Union (ITU).
Whereas the Global System for Mobile Communications (GSM) 
standard is a specification of an entire network 
infrastructure, the CDMA interface relates only to the air 
interface—the radio part of the technology. For example, 
GSM specifies an infrastructure based on internationally 
approved standard, while CDMA allows each operator to 
provide the network features as it finds suited. On the air 
interface, the signalling suite (GSM: ISDN SS7) work has 
been progressing to harmonise these features.
After a couple of revisions, IS-95 was superseded by the IS-
2000 standard (CDMA2000). This standard was introduced to 
meet some of the criteria laid out in the IMT-2000 
specification for third generation (3G) cellular. It is 
also called 1xRTT which means "1 times Radio Transmission 
Technology" because IS-2000 uses the same 1.25 MHz carrier 
shared channel as the original IS-95 standard. A related 
scheme called 3xRTT uses three 1.25 MHz carriers for a 3.75 
MHz bandwidth that would allow higher data burst rates for 
an individual user, but the 3xRTT scheme has not been 
commercially deployed. More recently, QUALCOMM has led the 
creation of a new CDMA-based technology called Evolution-
Data Optimized (1xEV-DO, or IS-856), which provides the 
higher packet data transmission rates required by IMT-2000 
and desired by wireless network operators.
This CDMA system is frequently confused with a similar but 
incompatible technology called Wideband Code Division 
Multiple Access (W-CDMA) which is the basis of the W-CDMA 
air interface. The W-CDMA air interface is used in the 
global 3G standard UMTS and the Japanese 3G standard FOMA, 
by NTT DoCoMo and Vodafone; however, the CDMA family of US 
national standards (including cdmaOne and CDMA2000) are not 
compatible with the W-CDMA family of ITU standards.
Another important application of code division 
multiplexing — predating and distinct from CDMA — is the 
Global Positioning System (GPS).
The QUALCOMM CDMA system includes very accurate time 
signals (usually referenced to a GPS receiver in the cell 
base station), so cell phone CDMA-based clocks are an 
increasingly popular type of radio clock for use in 
computer networks. The main advantage of using CDMA cell 
phone signals for reference clock purposes is that they 
work better inside buildings, thus often eliminating the 
need to mount a GPS antenna outside a building.

First it is important to know that one is an access scheme
and the other is not.
GSM is Global System for Mobile Communications which uses
FDMA/TDMA access schemes. In GSM users are seperated in time
and frequency.
While CDMA which is known as Code Division Multiple access
is an access scheme used by UMTS where users are seperated
by different codes but all users can transmit at the same
time and on the same frequencies in the same region of space.

ans 11.. is copied from somewhere else.... just copy and 
paste...

GSM uses a specific frequency for each user in the cell,
while cdma uses the  entire available spectrum

Gsm-global system for mobile communication.which can takes
place thorugh sim cards.it uses bandwidth in time slots.

cdma-code division multiple access.which uses a code
included in handset.thruogh code communication is takes place.
we cant change ourself from one hand set to other.

GSm only can connect 30-35 peoples. but in CDMA 70 peoples 
can connect.

the main difference is speed .
cdma is faster for transferring data as compared to gsm.
cdma interferes with voice calls but gsm does not interfere 
with voice calls.

In CDMA technology adjacent channel interference is very 
low compared to GSM.In cdma the power consumption is very 
low it takes 23 to 30 dBm.But in GSM the power consumption 
is very high comparitive to CDMA the lower limit is 30 dbm.

GSM-gsm is global system of  mobile and in gsm ftma and tdma technqs are used.it depends on frequency and yime slot 
cdma= scdma is code division multiple aceess technq and use cdma technq.in cdma there is proper code for every channel to set up a call

GSM (Global System for Mobile Communications)

GSM is the “branded” term referring to a particular use of 
TDMA (Time-Division Multiple Access) technology.
GSM is the dominant technology used around the globe and is 
available in more than 100 countries.
It is the standard for communication for most of Asia and 
Europe.
GSM operates on four separate frequencies: You’ll find the 
900MHz and 1,800MHz bands in Europe and Asia and the 850MHz 
and 1,900MHz (sometimes referred to as 1.9GHz) bands in 
North America and Latin America.
GSM allows for eight simultaneous calls on the same radio 
frequency and uses “narrowband” TDMA, the technology that 
enables digital transmissions between a mobile phone and a 
base station.
With TDMA the frequency band is divided into multiple 
channels which are then stacked together into a single 
stream, hence the term narrowband. This technology allows 
several callers to share the same channel at the same time.


CDMA (Code Division Multiple Access)
CDMA takes an entirely different approach from GSM/TDMA. 
CDMA spreads data out over the channel after the channel is 
digitized.
Multiple calls can then be overlaid on top of one another 
across the entire channel, with each assigned its 
own “sequence code” to keep the signal distinct.
CDMA offers more efficient use of an analog transmission 
because it allows greater frequency reuse, as well as 
increasing battery life, improving the rate of dropped 
calls, and offering far greater security than GSM/TDMA.
For this reason CDMA has strong support from experts who 
favor widespread development of CDMA networks across the 
globe.
Currently, you will find CDMA mostly in the United States, 
Canada, and North and South Korea. (As an interesting 
aside, CDMA was actually invented for the military during 
World War II for field communications.)

GSM (Global System for Mobile Communications).............. 
GSM is the “branded” term referring to a particular use of 
TDMA (Time-Division Multiple Access) technology. GSM is the 
dominant technology used around the globe and is available 
in more than 100 countries. It is the standard for 
communication for most of Asia and Europe. GSM operates on 
four separate frequencies: You’ll find the 900MHz and 
1,800MHz bands in Europe and Asia and the 850MHz and 
1,900MHz (sometimes referred to as 1.9GHz) bands in North 
America and Latin America. GSM allows for eight 
simultaneous calls on the same radio frequency and 
uses “narrowband” TDMA, the technology that enables digital 
transmissions between a mobile phone and a base station. 
With TDMA the frequency band is divided into multiple 
channels which are then stacked together into a single 
stream, hence the term narrowband. This technology allows 
several callers to share the same channel at the same time. 

2. CDMA (Code Division Multiple 
Access).............................. CDMA takes an 
entirely different approach from GSM/TDMA. CDMA spreads 
data out over the channel after the channel is digitized. 
Multiple calls can then be overlaid on top of one another 
across the entire channel, with each assigned its 
own “sequence code” to keep the signal distinct. CDMA 
offers more efficient use of an analog transmission because 
it allows greater frequency reuse, as well as increasing 
battery life, improving the rate of dropped calls, and 
offering far greater security than GSM/TDMA. For this 
reason CDMA has strong support from experts who favor 
widespread development of CDMA networks across the globe. 
Currently, you will find CDMA mostly in the United States, 
Canada, and North and South Korea. (As an interesting 
aside, CDMA was actually invented for the military during 
World War II for field communications.)

In cellular service there are two main competing network
technologies: Global System for Mobile Communications (GSM)
and Code Division Multiple Access (CDMA). Cellular carriers
including Sprint PCS, Cingular Wireless, Verizon and
T-Mobile use one or the other. Understanding the difference
between GSM and CDMA will allow you to choose a carrier that
uses the preferable network technology for your needs.

The GSM Association is an international organization founded
in 1987, dedicated to providing, developing, and overseeing
the worldwide wireless standard of GSM. CDMA, a proprietary
standard designed by Qualcomm in the United States, has been
the dominant network standard for North America and parts of
Asia. However, GSM networks continue to make inroads in the
United States, as CDMA networks make progress in other parts
of the world. There are camps on both sides that firmly
believe either GSM or CDMA architecture is superior to the
other. That said, to the non-invested consumer who simply
wants bottom line information to make a choice, the
following considerations may be helpful.

Coverage: The most important factor is getting service in
the areas you will be using your phone. Upon viewing
competitors' coverage maps you may discover that only GSM or
CDMA carriers offer cellular service in your area. If so,
there is no decision to be made, but most people will find
that they do have a choice.

Data Transfer Speed: With the advent of cellular phones
doing double and triple duty as streaming video devices,
podcast receivers and email devices, speed is important to
those who use the phone for more than making calls. CDMA has
been traditionally faster than GSM, though both technologies
continue to rapidly leapfrog along this path. Both boast
"3G" standards, or 3rd generation technologies.

EVDO, also known as CDMA2000, is CDMA's answer to the need
for speed with a downstream rate of about 2 megabits per
second, though some reports suggest real world speeds are
closer to 300-700 kilobits per second (kbps). This is
comparable to basic DSL. As of fall 2005, EVDO is in the
process of being deployed. It is not available everywhere
and requires a phone that is CDMA2000 ready.

GSM's answer is EDGE (Enhanced Data Rates for GSM
Evolution), which boasts data rates of up to 384 kbps with
real world speeds reported closer to 70-140 kbps. With added
technologies still in the works that include UMTS (Universal
Mobile Telephone Standard) and HSDPA (High Speed Downlink
Packet Access), speeds reportedly increase to about 275—380
kbps. This technology is also known as W-CDMA, but is
incompatible with CDMA networks. An EDGE-ready phone is
required.

In the case of EVDO, theoretical high traffic can degrade
speed and performance, while the EDGE network is more
susceptible to interference. Both require being within close
range of a cell to get the best speeds, while performance
decreases with distance.

Subscriber Identity Module (SIM) cards: In the United States
only GSM phones use SIM cards. The removable SIM card allows
phones to be instantly activated, interchanged, swapped out
and upgraded, all without carrier intervention. The SIM
itself is tied to the network, rather than the actual phone.
Phones that are card-enabled can be used with any GSM carrier.

The CDMA equivalent, a R-UIM card, is only available in
parts of Asia but remains on the horizon for the U.S.
market. CDMA carriers in the U.S. require proprietary
handsets that are linked to one carrier only and are not
card-enabled. To upgrade a CDMA phone, the carrier must
deactivate the old phone then activate the new one. The old
phone becomes useless.

Roaming: For the most part, both networks have fairly
concentrated coverage in major cities and along major
highways. GSM carriers, however, have roaming contracts with
other GSM carriers, allowing wider coverage of more rural
areas, generally speaking, often without roaming charges to
the customer. CDMA networks may not cover rural areas as
well as GSM carriers, and though they may contract with GSM
cells for roaming in more rural areas, the charge to the
customer will generally be significantly higher.

International Roaming: If you need to make calls to other
countries, a GSM carrier can offer international roaming, as
GSM networks dominate the world market. If you travel to
other countries you can even use your GSM cell phone abroad,
providing it is a quad-band phone (850/900/1800/1900 MHz).
By purchasing a SIM card with minutes and a local number in
the country you are visiting, you can make calls against the
card to save yourself international roaming charges from
your carrier back home. CDMA phones that are not
card-enabled do not have this capability, however there are
several countries that use CDMA networks. Check with your
CDMA provider for your specific requirements.

According CDG.org, CDMA networks support over 270 million
subscribers worldwide, while GSM.org tallies up their score
at over 1 billion. As CDMA phones become R-UIM enabled and
roaming contracts between networks improve, integration of
the standards might eventually make differences all but
transparent to the consumer.

The chief GSM carriers in the United States are Cingular
Wireless, recently merged with AT&T Wireless, and T-Mobile
USA. Major CDMA carriers are Sprint PCS, Verizon and Virgin
Mobile. There are also several smaller cellular companies on
both networks.

GSM:global syetm for  mobile communication & CDMA means 
code division multiple access.In GSM mobiles we can use sim 
card of any compony while we cant do it in CDMA

what is
the difference between GSM and CDMA, the two leading technologies?
Both GSM (Global System for Mobile Communications) and CDMA (Code
Division Multiple Access) are technologies that work on radio
frequencies, with the mobile phone handset being the antennae receiving
the signal. The range of each technology is different, and they also
have different rates and modulation schemes, and that is why handsets
are different between the two technologies. GSM uses SIM cards
(Subscriber Identity Module) whereas, CDMA based phones do not. In the
case of GSM networks, it is the SIM card that is tied to the network,
where on CDMA networks it is the handset itself that is linked to the
carrier. This means that a SIM card can be placed in pretty much any
handset and still receive GSM coverage, but once a CDMA phone's
subscription has ended, the phone is outmoded. CDMA technology has a
version of the SIM card, the RUIM (Removable User Identity Module) but
is not as widely popular in the US because it is the handsets which
must be linked to the carrier.

GSM tends for Global System for mobile communication.It is 
based on TDMA & FDMA technique.CDMA  is code division 
multiple access it is based on multiple access technique.
In this technology the conversation betwwen two user are 
coded so it is more secure than GSm.