[Looselips]

from CNET:

Q: What exactly is the difference between CDMA and GSM, and how does that translate to real-world functionality?

A: You could write a book describing the technical differences between the two technologies, but I'll spare you the gritty details by describing how these variations may influence your mobile shopping decisions. In the most general sense, CDMA sends wireless signals in a series of unique codes, while GSM divides signals into a series of individual time slots (for more information, see the glossary in our quick guide to 3G). To you, that means a few things. CDMA networks tend to have more capacity so that more callers can use the network at one time, and they tend do a better job during handoffs, when your call is passed from one tower to another. CDMA also has more widespread coverage in the United States, especially when you count analog roaming, and offers more stateside high-speed data networks. Finally--and I know I'm opening a Pandora's box here--CDMA supporters, who are likely to be the most vociferous defenders, usually argue that their technology offers better call clarity. Keep in mind, though, that it's not necessarily a fact since individual call quality is a matter of opinion, and it depends on a multitude of factors that can be beyond your control.

On the other hand, GSM has its own advantages. GSM's advocates argue that because it is a newer technology (though it is based on the older TDMA networks), it's better equipped for the conversion to 3G. Also, GSM is more widely used than CDMA, with service available in more countries around the globe. CDMA is adding regions as time goes on, but if want a true world phone, GSM is your choice. GSM also uses a SIM card, so it's much easier to switch your phone number and your contacts between handsets. And speaking of phones, GSM phones usually require less battery power than CDMA, and at least in the United States, the GSM carriers (Cingular and T-Mobile) have a more varied selection of phones that include such higher-end features as Bluetooth than do CDMA providers Sprint and Verizon.

http://reviews.cnet.com/4520-3504_7-...ml?tag=nl.e723

[sneak]

I personally think its not necessary to compare the two. GSM will eventually turn into WCDMA (if I remember correctly), and I'm sure CDMA will change, too.

Clearly if you want to travel internationally GSM is the way to go. For data, right now CDMA is the way, as well as for roaming.

I like my phone selection with GSM better, but there are some nice CDMA phones in the pipe.

[topher694]

The battery part is backwards... CDMA requires less power.

[HiTEC]

Easier to go to 3G with GSM? Isn't that backwards too??

In order for GSM to go 3G, they need to dump the TDMA air interface and totally CDMA to the CDMA air interface (WCDMA).

[tkrandall]

GSM is newer? Huh?

[topher694]

You're both right, I missed those. CDMA is newer, and CDMA is a much easier transition to 3G.

[slffl]

Well I'll be the first to say that there is a definent difference in call clarity and quality between the two technologies. Whenever I talk to someone using Cingular or Tmobile I am barely able to make out what they are saying because of the break-ups and static. Sprint quality has been much, much better.

The only thing I'm missing right now is the sweet technology part. I really want a super thin phone, but I don't see sprint or verizon getting one anytime soon.

[wordpowa]

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cdma isn't on time at all. the service is there but the revolutionary phone technology isn't. thats my main beef with sprint. being limited to thier poor selection of phones.

[fl00d_pr0z]

What kinda "Compairison" is that ? CMDA is newer as far as I know, and I thought also as said above, CMDA used less battery life.

[Matt]

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Originally Posted by topher694

The battery part is backwards... CDMA requires less power.

Perhaps, but I have yet to feel much heat from my gsm phone. Even while charging. It's all subjective.

[topher694]

Originally Posted by PDXMatt

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Perhaps, but I have yet to feel much heat from my gsm phone. Even while charging. It's all subjective.

Yeah, I've never got that whole phone heating up thing, I've not sure if the it's the phone's construction or what, but my old TDMA phone used to get HOT.

[slffl]

I'm almost positive GSM uses less power unless CDMA has made some kind of changes in the past few years.

[topher694]

Originally Posted by slffl

I'm almost positive GSM uses less power unless CDMA has made some kind of changes in the past few years.

CDMA is designed to work just above the "noise floor" meaning it uses as little power as it can, the most power a CDMA phone will put out is around 0.2 watts and usually less. In GSM I think the minimum the phones put out is 0.2. Heck the max power a CDMA (tower) antenna puts out is 15 watts (which supports many more users than a single GSM antenna) and I think GSM antennas usually max out at around 100 watts or so.

[wordpowa]

Wirelessly posted (i had no other choice.: Mozilla/4.0 (MobilePhone MM-5600/US/1.0) NetFront/3.1 MMP/2.0)

fact remains cdma phones are in a sense... boring.

[slffl]

Well what about the phones? Why is it that GSM phones can be smaller and have smaller batteries yet have more talk and standby time? As well as some phones need to have special designs (ie Treo 600) because of the radiation coming from the phone.

Originally Posted by topher694

CDMA is designed to work just above the "noise floor" meaning it uses as little power as it can, the most power a CDMA phone will put out is around 0.2 watts and usually less. In GSM I think the minimum the phones put out is 0.2. Heck the max power a CDMA (tower) antenna puts out is 15 watts (which supports many more users than a single GSM antenna) and I think GSM antennas usually max out at around 100 watts or so.