What is the Difference Between GSM and CDMA?

They too use CDMA. I see a little pattern forming here. >3rd: GSM you might be able to move a chip from phone to phone...but first you have to ask yourself if you're living somewhere like the states...why are you switching back and forth on phones that much.

Also with carriers like Verizon, you can switch via phone/internet in less than a minute and your new phone will be working with the ability to have all your contacts moved over WIRELESSLY...and saved to your account online! Your GSM phone doesn't automatically upload contacts daily wirelessly. Sucks for GSM people if they lose there phone.

Consumers like new phones about every 2 years or so just like they update their computers, laptops, operating systems, game consoles, cars, TVs,... I take it you are still using the same brick you had in 1995 when they invented CDMA? >4th: GSM is evolving to CDMA! What is wrong with you people?

Most countries have already mandated that WCDMA is the global standard, because the standard GSM network can't handle what they have already. You are confusing upper layer protocols with underlying RF modulation and channel access schemes. Both 3G CDMA (1xRTT, EVDO) and 3G GSM (UMTS, HSPA) use the same RF modulation and access scheme WCDMA.

Both network handle their upper layers in a different way, but there really are no huge earth shaking differences. >5th: There are very very few phones that work on all the networks, and there is no such thing as every single network. >You have CDMA: 450(poland/norway/portugal/sweden/demmark/iceland)/700(soon)/800/1900mhz.

>Most GSM tri/quad band phones only support up to 4! >Quad Band CDMA Phones: only up to 4! I think you are confusing a whole lot of issues here.

1) RF spectrum 2) RF Modulation and channel access and 3) upper layer protocols.