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What would be better GSM or CDMA?

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leoren_tm

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today what would be best??
GSM or CDMA??
 

Re: 3G!!!

I think CDMA is more flexable and more secure and easer to be developed than GSM.
any how It all depends on what you need (research, studing or work).

Added after 1 minutes:

by the way there is also what is after 3G which is UMTS.
 

Re: 3G!!!

moh-osamah said:
I think CDMA is more flexable and more secure and easer to be developed than GSM.
any how It all depends on what you need (research, studing or work).

Added after 1 minutes:

by the way there is also what is after 3G which is UMTS.
Click to expand...
ive heared that cdma leads the 3G, and now....GSM is trying to duplicate what CDMA has...is that true??
 

Re: 3G!!!

when GSM and IS-95 were firstly released ,GSM was better a than cdma ,also it was more spread than IS-95 as many standarization body in europpe like ETSI contribute in standarizing this technolgy,on contrary cdma was standarized by TIA only so it was used in north america and some countries in asia.

nowdays,to enhance utilization of spectrum usage ,all standarization bodies all over the world recommended cdma as an access technique to air interface for 3G technologies UMTS and cdma2000.

Now days ,cdma becomes the most powerful multiple access technique.
 

Re: 3G!!!

CDMA is better of course from the point of networks u can maximize the use of the channel resource over more users as well as maintaing providing good QoS
transmission point of view the delay is nearly neglianle that u can use video as well as live audio transmission with acceptable delay.
 

Re: 3G!!!

i think tha the most powerful multiple access technique is WCDMA
 

Re: 3G!!!

How about a better question. Your question of "Which is better, GSM or CDMA" is like asking "How high is up?".

First, you have to decide what you mean by "better". You could mean

-More widely used
-lowest cost implementation
-highest spectral efficiency (Bits/Sec/Hz as a metric)
-Subscriber capacity per base station

and that's just what comes to me on a Saturday afternoon.

Dave
www.keystoneradio.com
 

Re: 3G!!!

Insteresting question. Some personal opinion.

GSM is an extremely successful standard. That is why different manufacture can produce it and their products works together. (I also heard that GSM is mainly done by telecommunication guys so that the standard is simple, as compared to nowadays standard is so complex as computer guys involved.)

CDMA dominates the 3G standard for some historical reasons. Originally used in military application, CDMA has many problem when people want to apply it to comerical use. The big player, Qualcomm, advertised its superiority over GSM and european guys followed Qualcomm.

Ten years passed and we found that the world is still shared by GSM and CDMA. For voice service, GSM is good enough and even from theoretical point of view, CDMA is not really very advanced over GSM for voice service. (This is kind of humorious, but math tells us so.)

What is to do next? We know CDMA has its data service, known for EV-DO and it is fast than its counterpart in GSM (called EDGE). However, what is happened in EV-DO is that there is no CDMA technology in there, and it is TDMA. :) Why? In the last ten years, there is more understanding of wireless communication from information theorerical perspective and what IT tells us is that we should not do CDMA.

What is happening in 4G? No CDMA at all. Most of the system is OFDM(A).
 

Re: 3G!!!

leoren_tm said:
today what would be best??
GSM or CDMA??
Click to expand...

Dear leoren_tm

There are alot key differences between GSM and CDMA. Maybe,CDMA has many advantages over GSM,but GSM is spread in more countries at the world due to its own advantages,so each of these technologies has its own advantages,so you can't say that there is one that is better than the other.but what iam sure is that if you know GSM well,you have also to know the CDMA theory also as the 3G of GSM is UMTS which is based on WCDMA and WCDMA is based on the normal CDMA theory

Best Regards
Ibrahim Sayed
 

Re: 3G!!!

thanks for the comment, i read some article, saying the growth of CDMA exceeded 100%, im a user of GSM, if i call, it would only be 2hour or less, this is bcoz, GSM uses lot power and also considering the aspect, there some report that bcoz of antena or the transmiiter of GSM couse health a\hazard..while CDMA uses 10 times less on power usage..
plss discussed
 

GSM vs CDMA?

Theoriticly CDMA using a lower power because it is using spread spectrum so the power used by this technology is so much lower than GSM
But my friend who using CDMA cellphone complain me that their cellphone getting warm even hot after they calling their friend in 1 hour or more

The question is why?
Is it because the antena differences?

In my opinion, CDMA n GSM having their own way to express what they have
CDMA may has a good perfomance and speed in transferring data but they having a problem in power control too GSM also having any problem such as the number of user they can handle in one cell and their small coverage compare to CDMA

Honestly, we may compare CDMA and GSM about their advantage or their disadvantage
okay?

regards,

kesuma
 

Re: 3G!!!

leoren_tm said:
thanks for the comment, i read some article, saying the growth of CDMA exceeded 100%, im a user of GSM, if i call, it would only be 2hour or less, this is bcoz, GSM uses lot power and also considering the aspect, there some report that bcoz of antena or the transmiiter of GSM couse health a\hazard..while CDMA uses 10 times less on power usage..
plss discussed
Click to expand...

Dear leoren_tm

CDMA uses less power than GSM due to using spread spectrum technique,which is used as many users are utilizing the same frequency,and so to achieve that we spread the signal in frequency and so its power decreases,so each transmitter(either MS or BTS)transmits with a low power,and to sustain this low power,power control is done in a very effective way at CDMA,while at GSM power control may be done or not according to the operator choice at different cells and if power control didn't implemented,each TX will transmit with its highest power,so in GSM alot of power is consumed conradicted to CDMA

Best Regards
Ibrahim Sayed
 

Re: 3G!!!

do u have book on it
 

Re: 3G!!!

sajidiiui said:
do u have book on it
Click to expand...

Dear sajidiiui

I've hard copies,but i'll try to get a soft copy and send it

Best Regards
Ibrahim Sayed
 

CDMA fenomena

Anyone can help me to explain why when we use CDMA mobile phone to call our friend in a long period of time, we'll feel warm even hot enough in our ear?
Assume that we didn't use a handsfree so we use the cellphone directly to our ear
Anyone can explain me this fenomena?

We know that CDMA use a lower power in transmitting signals than in GSM

Thanks,
 

Re: GSM vs CDMA?

kesuma said:
Theoriticly CDMA using a lower power because it is using spread spectrum so the power used by this technology is so much lower than GSM
But my friend who using CDMA cellphone complain me that their cellphone getting warm even hot after they calling their friend in 1 hour or more

The question is why?
Is it because the antena differences?

In my opinion, CDMA n GSM having their own way to express what they have
CDMA may has a good perfomance and speed in transferring data but they having a problem in power control too GSM also having any problem such as the number of user they can handle in one cell and their small coverage compare to CDMA

Honestly, we may compare CDMA and GSM about their advantage or their disadvantage
okay?

regards,

kesuma
Click to expand...

ok...becuase of the spread spectrum theory., CDMA offers a high security...
anyone dis agree??
it canot be jam
 

Re: 3G!!!

For the commertial use, people did not care too much about the security. For the military use, it is a different story. Qualcomm monoplies the IS-95 and IS-2000 CDMA chip and it also would like to duplicate its sucessful in the WCDMA chip. However, Nokia, Broadcom etc. do not want Qualcomm to dominate the WCDMA chip and there are a lot of law suits between Qualcomm and other wireless companies in UA and European.
 

Re: 3G!!!

uhmmm...
i interested on it..
can you give me more detail??
thx
 

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