Help GSM v. CDMA

[Android Question]

What is GSM, what is CDMA, and which is better?

 

[kate]

There are two types of cell phone technology - GSM and CDMA. GSM is much more common worldwide, and is easier to move an unlocked phone between carriers.

AT&T and T-Mobile are GSM, Verizon and Sprint are CDMA.

By better do you mean better reception? Reception depends on signal strength and how close you are to the tower. Every location is different.

 

[MLSS]

GSM is much better than CDMA. We have both in our house. AT&T and Sprint.

At the end of the day though, you have to go with the carrier that fits your needs. Coverage, pricing, ect......

 

[Hadron]

We don't know where on the planet you are, but unless you are in North America the question is probably irrelevant to you as there are very few CDMA networks outside that continent.

If you have the choice, the main question is coverage where you use the device, and pricing. But as Kate says it's much easier to swaps devices with GSM as you just need to insert your SIM card into a different phone and that's it - your contract and number move with the SIM - whereas with CDMA you need to get the carrier to register a new handset to your account.

There are technical differences in the air interfaces etc, but if that interests you then you can read up about them from many sources (if you aren't interested or are not at least a little familiar any attempt to briefly explain here may well cause more confusion than it saves!).

 

[AZgl1500]

GSM is much better than CDMA. We have both in our house. AT&T and Sprint.

At the end of the day though, you have to go with the carrier that fits your needs. Coverage, pricing, ect......

Ummmm, I've been in the radio business since 1958.

What you just said is not very substantive, because you don't have a point of reference on the signals.

Two difference carriers, two different cell sites, two different phones, and you are in a home with a lot of metal causing weird reflections of the incoming cell site signals.

To make such a determination, you must have a Cell Phone Test Analyzer and that is not a cheap instrument by any means.

"and the end of the day", it will be "the signal that provides the "Best SNR, or Signal to Noise Ratio".
You might say the "bars look the same" but the bars don't mean jack snill.... you must have knowledge of the actual dBm signal strength and look at the demodulation to see how well it fairs with the original waveform.

That said, I personally have never used my Oscilloscope to compare the output of a GSM phone versus the output of a CDMA phone.

At your home, it is the carrier that saturates the home's floor plan the strongest. That is the one that will win in the comparison contest... Move a half mile and try the same test, and quite likely the other carrier's phone will be better.

Our cell phones move about in a 3D manner, the cell towers are Land Locked with a Ball and Chain, they can't move. So when you move, it changes the signal path, and at the frequencies cell phones are operating at, you can hold up a tin cookie sheet and make a cell phone signal get worse or better. Just wave the metal pan around a bit and it will reflect that signal all over the place. The HVAC ducts in our homes are infamous for destroying the best laid plans of the engineers... all kinds of weird reflection patterns occur there....

 

[MLSS]

Ummmm, I've been in the radio business since 1958.

What you just said is not very substantive, because you don't have a point of reference on the signals.

Two difference carriers, two different cell sites, two different phones, and you are in a home with a lot of metal causing weird reflections of the incoming cell site signals.

To make such a determination, you must have a Cell Phone Test Analyzer and that is not a cheap instrument by any means.

"and the end of the day", it will be "the signal that provides the "Best SNR, or Signal to Noise Ratio".
You might say the "bars look the same" but the bars don't mean jack snill.... you must have knowledge of the actual dBm signal strength and look at the demodulation to see how well it fairs with the original waveform.

That said, I personally have never used my Oscilloscope to compare the output of a GSM phone versus the output of a CDMA phone.

At your home, it is the carrier that saturates the home's floor plan the strongest. That is the one that will win in the comparison contest... Move a half mile and try the same test, and quite likely the other carrier's phone will be better.

Our cell phones move about in a 3D manner, the cell towers are Land Locked with a Ball and Chain, they can't move. So when you move, it changes the signal path, and at the frequencies cell phones are operating at, you can hold up a tin cookie sheet and make a cell phone signal get worse or better. Just wave the metal pan around a bit and it will reflect that signal all over the place. The HVAC ducts in our homes are infamous for destroying the best laid plans of the engineers... all kinds of weird reflection patterns occur there....

I wasn't really looking to get my balls busted today, Referring to "home" was I reference to my household. I wasn't trying to specify that signal was better at my house.

Congrats on all the knowledge and experience, but I'm using common sense, and my experience. Using both, I can say that GSM is better than CDMA. That's probably one of the reasons it is being phased out.

 

[mikedt]

Don't think there's any plans for phasing out CDMA here yet.

 

[kate]

Using both, I can say that GSM is better than CDMA. That's probably one of the reasons it is being phased out.

Long term both GSM and CDMA will be phased out as networks move towards LTE.

AT&T plans to discontinue 2G GSM by 2017.

 

[AZgl1500]

I wasn't really looking to get my balls busted today, Referring to "home" was I reference to my household. I wasn't trying to specify that signal was better at my house.

Congrats on all the knowledge and experience, but I'm using common sense, and my experience. Using both, I can say that GSM is better than CDMA. That's probably one of the reasons it is being phased out.

I went back and reread what I posted, and I don't see where I was trying to hammer down on you.
All I was trying to do was explain how different results can be seen in different areas.

As for CDMA being inferior and being "phased out"? That won't be happening any time soon as the bandwidth requirements for LTE are immense, and in weak signal areas, LTE just can't function at all.

Just this morning, I was in a doctor's office building and on my Note 4 there was just barely 1 bar showing and the 3g signal indicator was all I saw the whole time I was there.... about 2 hours for the most part "without internet" because every site I wanted to look at is full of graphics.... what website isn't these days?

I wanted to read world news, BBC & CNN would not even load up, Fox News was way slow, I only saw the header pages and then gave up on that. None of my local TV news stations would display more than just their header....

Nope, CDMA will be around for at least two more decades, so get used to it or use a different carrier.

 

[MLSS]

www.androidauthority.com/verizons-2g-3g-cdma-networks-out-by-2021-121694/

 

[MLSS]

Once Verizon starts the phase out, sprint will follow.

 

[Curtis1973]

my CDMA works great with my tin foil hat

 

[mikedt]

My tin foil hat got blacklisted.

 

[Sams7]

What is GSM, what is CDMA, and which is better?

I don't think one or the other is better