CDMA vs. GSM There are many models of Treo smartphone, from the old Handspring 180 to the newest Palm Treo 700p, but within these models there are two important distinct types of handset: GSM and CDMA.

For instance, a Treo 600 could be a CDMA or GSM handset, and the difference is very important!

The digest for lazy readers: GSM and CDMA are two types of mobile phone network. GSM is used all over the world, CDMA is largely restricted to the USA and North America. CDMA is often faster for data but using data blocks voice calls. GSM data is often slower but doesn't block voice calls. Tri and quad band GSM phones (like the Treo) can be used all over the world, CDMA phones can't. GSM phones use SIM cards, CDMA phones don't.

Why You Should Know The Difference

CDMA or GSM refers to the type of network technology the phone uses. Some carriers use CDMA and some use GSM. Your choice of carrier and the technology it uses for its network might make the difference between being productive and connected or ending up with no signal.

The Terms Explained

Really want to know? Prepare yourself now...

GSM (Global System for Mobile Communications).





CDMA (Code Division Multiple Access).

The showdown

CDMA (Code Division Multiple Access) vs. GSM (Global System for Mobile Communications).

Coverage

Both GSM and CDMA have good coverage all across the United States, however it is still important to choose the right network...

Data transfer methods

GSM’s high-speed wireless data technology, GPRS (General Packet Radio Service), usually offers a slower data bandwidth for wireless data connection than CDMA’s high-speed technology (1xRTT, short for single carrier radio transmission technology), which has the capability of providing ISDN (Integrated Services Digital Network)-like speeds of as much as 144Kbps (kilobits per second). However, 1xRTT requires a dedicated connection to the network for use, whereas GPRS sends in packets, which means that data calls made on a GSM handset don’t block out voice calls like they do on CDMA phones. Note: The new GSM EDGE technology means that GSM speeds have caught up with CDMA, but EDGE coverage and availability remains patchy.

GSM phones use SIM cards

The most obvious distinction between GSM and CDMA is the SIM (subscriber identity module) card, the onboard memory device in a GSM phone that identifies a user and stores their information. You can swap GSM SIM cards between phones which enables you to move all of your contact and calendar information over to a new handset with no hassle.

CDMA operators answer this flexibility with their own service that stores user data on the operator’s database. This service makes it possible to swap handsets with little trouble and also provides the ability to recover contact data even if their phone is lost or stolen. These services are usually available for GSM phones too, so it's not really an advantage of CDMA, more of a disadvantage is that they don't have SIM cards.

International Use

Where international useage is important, GSM really does win hands down. GSM networks are used in more than 74% of the markets across the globe, and so users of tri-band or quad-band GSM handsets can travel to Europe, India, and most of Asia and still use their cell phones. CDMA offers no multiband capability and is rare outside of the United States so it is not really much use for international travellers. You can also move the SIM of a GSM-based phone to any other GSM-based phone, or use a different SIM in your own phone, making GSM the optimal choice for international travelers who need connectivity.

Note: common 850MHz/1,900MHz GSM phones in the United States are not compatible with international standards. If you live in the United States and need to have cell phone access when you travel overseas you will need a tri-band or quad-band GSM phone with 900MHz and 1,800MHz bands. These types of phones will let you use your phone while in the United States and overseas without having to change handsets. You will, however, need to obtain a SIM card that works overseas.

Other considerations

CDMA phones tend to have better battery use. CDMA networks have more capacity and are generally better for data. CDMA also has more widespread coverage in the United States, especially when you count analog roaming, and offers more stateside high-speed data networks. Some people claim CDMA has better call clarity, others say GSM does. CDMA is often cheaper, especially for unlimited data plans.

Conclusion

If you like in the US and never travel oversees then CDMA appears to have many advantages over GSM, but if you live outside the US or travel oversees a lot then GSM is the only way to go!



See Wireless Carriers



*This was copied from mytreo.net wiki*