April 23rd, 2012, 07:55 PM
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accurate info
Hey there I thought id clear up some of the confusion here even though the thread is a couple months old its always nice to know.
Alrigh, Cdma2000(referred to somewhat inaccurately as just cdma) is a 3G cellular technology. Often incorporated in a cdma2000/IS-95 hybrid. It is the type of radio technology that allows voice and other streams to be transmitted wirelessly. The first form or evolution of it is 1xrtt which is basic cdma2000(ill just call it cdma )the next form that we see more commonly includes EV-DO Rev.A (unfortunately verizon hasn't upgraded to Rev. B or c and doesn't plan to). This stands for EVolution-Data Optimized. This is a sub technology of cdma which focuses on data specific transfers allowing cdma to focus on voice only for better voice quality. However both use the same stream so only one signal at a time is possible. Which is why verizon doesn't do voice and data simultaneously(except on 4G but lets get to that later). So basically verizon only has 3G and 4G. The other popular cellular technology used by att, tmobile, and most carriers around the world is gsm and the gsm based 3G which is UMTS and HSPA(HSDPA/HSUPA/and the almost 4G variant-HSPA+) gsm is a 2G tech which carries voice and used to use gprs for data but now uses EDGE and falls back on gprs in low coverage. Just like cdma it used one stream so no voice and data simultaneously. The 3G evolution of GSM is based on UMTS which is 3G voice technology, and hspa which is 3G data. These are two seperate streams and so voice and data can be used at the same time.
LTE is a 4G(depending on who you ask and what lte you refer to)technology that will eventually use data for voice transfer similar to VOIP like Skype and vonage. But currently only transfers data. Currently lte phones must use either cdma or umts/gsm for voice and lte for data which allows data and voice simultaneously.
2G/3G/4G do not themselves denote or refer to actual speeds.
Now that the cellular/radio crash course is over. 2G/3G toggles are meant for gsm based phones. Any cdma based phone cannot use them. So you don't need to worry about them at all
Now to throw you for a loop a few android phones and the newest iphone use Radios that can access both gsm and cdma! Also there is w-cdma which is not cdma but actually near identical to UMTS.
Hope this cleared things up. For more info search any of the terms I've mentioned on wikipedia. I'd provide links but I'm new to this particular form.
Search:
Cdma
Cdma2000
Is-95
Gsm
Gprs
EDGE
Umts
Hspa
EV-DO
Lte
W-cdma
Wimax
Tdma
And for chirps or 2-ways its the IDEN network.
All these are cellular technologies. There are more too. Its a complex world of radio waves.
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