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 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.
Which is the digital modulation used today in telecomn?
(whatever his question meant the answer was CDMA)
2) Why is walse code used? then, noncoherent detection,
coherent detection, Pn code(y it is used?) etc
1.What is the difference between Diplexer and Duplexer and
what position?
2. What is the different between CDU C and CDU A
3. How do you link a T1 from the 1st BTS to 2nd BTS
4. What is the value for TEI 1st T1?
5. What is the SSI?
Ask Questions on ANYTHING, that arise in your Daily Life at 
Site Map
