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Dear,
GSM and CDMA are two technologies used in mobile communication now a days. In CDMA we can use the same carrier freq for more than one user in the same cell whereas in GSM we can not. For GSM we an reuse the same freq in other cell maintaining a minimum distance.
Also GSM uses TDMA and FDMA.
Good Luck
GSM is a second generation (2G) mobile system that is being employed in most european countries and asean coutries. GSM (global system for mobile communications) is a digital cellular phone technology based on TDMA and FDMA.
CDMA meanwhile is not a digital cellular phone technology. It is a type of multiple access technique. refer to the following link to understand what is multiple access schemes. http://www.wtec.org/loyola/wireless/02_04.htm
GSM is using TDMA and FDMA.
However, due to limitations in frequency spectrum expecially for highly populated countires like USA and Korea, they are using CDMA (code division multiple access) in their 2G digital cellular phone technology (ex: IS95). CDMA's biggest advantage is ; its spread spectrum technique maximises spectrum efficiency.
All 3G based phone technology are using CDMA. Anyway this is a huge topic to explain, so I just gave some basics about GSM and CDMA.
and about the other diffrent the CDMA can provid bigest coverge for example in the place need 4 tower in GSM can dependent on one tower in CDMA
also have other point the subsriber traffic in CDMA can transfer at av.high B.W.
more then 10 once from GSM , so can support a many survice like video call
the big problem in CDMA is in synchronization in A-bis interface is dependent on V.SAT system and the transmission by V.SAT is unstable as required in wirless phone
if you still need other information about this subject i can give you a v.good paper in this field
CDMA has theoretically infinite capacity since all users are allocated different code and transmit same time at same frequency
GSM allocates each user (8 maximum) different time slots to transmit in the 200kHz channel i.e a combination of TDMA and FDMA.
CDMA has universal frequency reuse, same band in every cell (cluster size of 1)
GSM has a certain frequency reuse factor with a minimum co-channel distance
GSM is based on TDMA
See the following diagram
in cdma, every user employs whole bandwidh and the user is being distinguished by invidual PN code.
In GSM, every user is alloted a time slot in whole time and he has to utilize it during his turn.
Both of these systems used in the mobile telecommunication system, but in my opinion CDMA system is better because it gives you a very big band width with comparison to the GSM, also the modulation system is different between them.
the data rate is higher in CDMA.
there are many differences between cdma and GSM systems ,the multiple access technique GSM is TDMA OVER FDMA ,while in IS-95 IS cdma over FDMA.in general the capacity of cdma is larger than it in GSM because no of codes per carrier are larger than no of available time slots per carrier in GSM.The handover techniques GSM is hard handoff(between different cells) and softer handoff(within same cell),while in cdma hard,soft and softer handoff techniques are used.
i'll try to send u a table discuss the differences ASAP.
Read your article, very good points. I personally favor CDMA, although in the late 90s I favored GSM because of it's roaming abilities, but other than that, I think CDMA is much more efficient.
IN GSM A SINGLE FREQUENCY IS ASSIGNED TO A SPECIFIC USER IN A CELL AND THIS FREQUENCE CAN'T BE ASSIGNED TO ANOTHER USER IN THAT PARTICULER CELL, MAKING RESTRICTION ON FREQUNCE REUSE IN GSM.
WHEREAS IN CDMA YOU CAN ASSIGN A SINGLE FREQUNCE FOR MORE THAN ONE USER.
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