This comparizon is relevant to the US market where you can find both GSM and CDMA iPhone: with a GSM iPhone you can use it abroad paying a hefty roaming charge to ATT; with a CDMA iPhone you will not pay any roaming charge to Verizon and you can use it as an iPod Touch.
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Can someone please explain to me why they're referred to as GSM and CDMA...
- Thread starter zorahk
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Look, it's confusing as hell, but it seems like everyone here is partly right in one way or another.
Back in the days of 2G, GSM and CDMA referred to the technologies themselves. Now, they refer to the family of technologies.
GSM, UMTS (and it's descendants, HSPA and HSPA+) and LTE make up the GSM family because the same group that developed GSM developed UMTS and LTE. And most (or maybe all?) carriers that started with GSM are going to the GSM-UMTS-LTE upgrade path, so it's easier to refer to it as GSM. Is it right? No, not really, but it's like saying that you're going to buy some Kleenex when you're really buying the Puffs brand. It's a generic trademark now.
CDMA probably should have been called CDMA2000 from the start, as that was the name of the technology. CDMA was just the transport mechanism (it's like referring to your vehicle as a set of wheels. Not too specific. Is it a car? bike? truck?). But, laziness prevailed and the 2000 was dropped anytime it was mentioned, so it was marketed as CDMA, and it was the only cellular technology using the CDMA transport mechanism at the time, so the name stuck and when someone said CDMA, everyone knew they were talking about CDMA2000.
GSM, CDMA, etc, are all marketing terms, nothing else. The correct, technological terms for the iPhone are probably HSPA iPhone and EvDO iPhone - even though they offer GSM and CDMA2000 as a fallback, they're primarily used on HSPA and EvDO networks. And you can argue that calling the HSPA iPhone a CDMA iPhone is technically correct since HSPA uses the W-CDMA transport layer. But, marketing prevails so they're called GSM and CDMA - which refers to the family of technologies they use, not the technology itself.
It's confusing as hell, but just remember that the engineers and the marketing people have 2 different definitions of GSM and CDMA, and the marketing people are the ones making the advertisements.
That's not 100% correct. You can use a GSM iPhone overseas, put it in flight mode, use it as an iPod Touch and won't pay a dime in roaming. Likewise, you can use a CDMA iPhone in the small number of countries that have CDMA networks, use it as a phone, and give Verizon your life savings, arm, leg and first born when you get your bill with all the roaming fees.
Back in the days of 2G, GSM and CDMA referred to the technologies themselves. Now, they refer to the family of technologies.
GSM, UMTS (and it's descendants, HSPA and HSPA+) and LTE make up the GSM family because the same group that developed GSM developed UMTS and LTE. And most (or maybe all?) carriers that started with GSM are going to the GSM-UMTS-LTE upgrade path, so it's easier to refer to it as GSM. Is it right? No, not really, but it's like saying that you're going to buy some Kleenex when you're really buying the Puffs brand. It's a generic trademark now.
CDMA probably should have been called CDMA2000 from the start, as that was the name of the technology. CDMA was just the transport mechanism (it's like referring to your vehicle as a set of wheels. Not too specific. Is it a car? bike? truck?). But, laziness prevailed and the 2000 was dropped anytime it was mentioned, so it was marketed as CDMA, and it was the only cellular technology using the CDMA transport mechanism at the time, so the name stuck and when someone said CDMA, everyone knew they were talking about CDMA2000.
GSM, CDMA, etc, are all marketing terms, nothing else. The correct, technological terms for the iPhone are probably HSPA iPhone and EvDO iPhone - even though they offer GSM and CDMA2000 as a fallback, they're primarily used on HSPA and EvDO networks. And you can argue that calling the HSPA iPhone a CDMA iPhone is technically correct since HSPA uses the W-CDMA transport layer. But, marketing prevails so they're called GSM and CDMA - which refers to the family of technologies they use, not the technology itself.
It's confusing as hell, but just remember that the engineers and the marketing people have 2 different definitions of GSM and CDMA, and the marketing people are the ones making the advertisements.
That's not 100% correct. You can use a GSM iPhone overseas, put it in flight mode, use it as an iPod Touch and won't pay a dime in roaming. Likewise, you can use a CDMA iPhone in the small number of countries that have CDMA networks, use it as a phone, and give Verizon your life savings, arm, leg and first born when you get your bill with all the roaming fees.
i say GSM because i can. when i say my iphone is GSM...you all know my iphone has a sim card, and i'm more than likely on ATT.
If i were to say my phone is CDMA, you would know i'm on Verizon. tada...end thread.
If i were to say my phone is CDMA, you would know i'm on Verizon. tada...end thread.
You must have an incredibly short (rather, very selective) memory. Go back and read this thread.
This post precisely where you put your foot in your mouth by suggesting that I don't know what I'm talking about.
Feel free to chime in with any experience you've had servicing cell sites in the wee hours of the morning... or if you've ever even seen a mobile gateway with your own eyes.
Failing that, I suggest digressing from this particular topic because you obviously haven't understood whatever books you claim to have skimmed.
People like you are prime example of how/why the average person doesn't understand the proper definition for terms like CDMA & GSM and how they differ from CDMA-2000 and UMTS
This post precisely where you put your foot in your mouth by suggesting that I don't know what I'm talking about.
Feel free to chime in with any experience you've had servicing cell sites in the wee hours of the morning... or if you've ever even seen a mobile gateway with your own eyes.
Failing that, I suggest digressing from this particular topic because you obviously haven't understood whatever books you claim to have skimmed.
People like you are prime example of how/why the average person doesn't understand the proper definition for terms like CDMA & GSM and how they differ from CDMA-2000 and UMTS
I said it before, and I'll say it again.
All you're claiming is that you work in the industry so you must be right.
Please state why my earlier posts were incorrect and how yours were correct - because I was able to point out flaws with your earlier post - which I note you haven't denied are actually wrong.
What part of go-back-and-read-the-thread do you not understand?
https://forums.macrumors.com/posts/11855616/
Tarzanman: Back in the 2G days, this was the 'easy' way to differentiate between these two standards... but nowadays it is confusing because CDMA (code division multiple access) is a protocol/technology used by all cell phone radio networks
Daveoc64: No it's not.
You clearly don't know what you're talking about.
Two incorrect statements in the same post. In case you still lack the intelligence to comprehend your error (or the guts to admit it):
1. Yes, code division multiple access (CDMA) is certainly a protocol/technology used by all cell phone radio networks
2. It turns out that I do in fact know exactly what I am talking about.
Lets see you try to explain that away.
https://forums.macrumors.com/posts/11855616/
Tarzanman: Back in the 2G days, this was the 'easy' way to differentiate between these two standards... but nowadays it is confusing because CDMA (code division multiple access) is a protocol/technology used by all cell phone radio networks
Daveoc64: No it's not.
You clearly don't know what you're talking about.
Two incorrect statements in the same post. In case you still lack the intelligence to comprehend your error (or the guts to admit it):
1. Yes, code division multiple access (CDMA) is certainly a protocol/technology used by all cell phone radio networks
2. It turns out that I do in fact know exactly what I am talking about.
Lets see you try to explain that away.
I already explained earlier that UMTS uses W-CDMA as an air interface, but that doesn't mean that the rest of the system is anything like CDMA2000.
I said it would be like saying Cars and Trains are the same because they both have wheels.
In the context of saying GSM or CDMA to refer to UMTS/GSM and CDMA2000 (as this thread is actually about) I felt that was an important distinction to make.
People aren't talking about Air Interfaces here. GSM isn't an air interface. Nor is UMTS. Hence why I didn't (and still don't) think your post was a correct response.
He never said UMTS is anything like CDMA2000. He said "CDMA (code division multiple access) is a protocol/technology used by all cell phone radio networks"
What part of that statement is wrong? UMTS uses CDMA. CDMA2000 uses CDMA. He's 100% correct IMO.
Hmmm, I didn't say anything about CDMA2000 in my post (feel free to read it again. I even quoted it for you). Your selective memory at work again, no doubt. How about you *not* put words in my mouth?
Thats a laugh. If you weren't as confused and mistaken over the terms (and their definition/proper use) as the people you are trying to 'help', then you would have immediately recognized that I made that distinction. Maybe the words were too complicated for you?
Remember what I said about you not knowing what you're talking about?
You go on thinking whatever you want. Just don't be surprised when the next guy calls you daft to your face.
It's not correct because he quoted another poster NOT talking about Air Interfaces.
To say that we can no longer distinguish between GSM/UMTS and CDMA2000 (which is the subject of this thread - so any responses to this thread should be framed with that in mind) because both of them use CDMA (as an air interface) is simply wrong.
People distinguish between GSM and iDEN (as used by Sprint) perfectly well (despite both using TDMA as an air interface). Nobody would make the point that Tarzanman has about those two technologies.
His post is correct that both UMTS and CDMA2000 share CDMA as an air interface, but I don't consider that relevant to people using the term "CDMA" to describe a CDMA2000 network.
When you say "I have a CDMA iPhone", very few people will think: "Oh, they must mean the W-CDMA iPhone that AT&T sells".