CDMA stands for Code Division Multiple Access. This is a telecommunications technology that is actually very important. 

 The tech speak 

 From a technical point of view, CDMA uses spread-spectrum technology and special coding schemes that allow more than one user to use the same radio channel. It's not to be confused with TDMA (Time Division Multiple Access) which divides the access to the channel by time, and FDMA (Frequency Division Multiple Access) which does so by frequency.

  For the normal person, the way to understand this is by simply thinking of different ways in which we communicate with each other, say, in the office. To allow everyone to communicate, each person can either speak at a different time (which is what time division is), a different frequency (or a pitch – this is frequency division) or in a different code (a language – this is code division). This allows everyone to use the same channel (the office) and not interfere with each other. 

 What this means for you and I 

 When it comes to cellular technology and cellular phones, we all need to use the same network to talk to each other. CDMAone and CDMA2000 are two cellular technologies that work off the CDMA idea above. Strictly speaking, these terms refer to only cellular technologies but telecommunications companies will speak of CDMA when they mean CDMAONE and CDMA2000.  

 In North America there are two main types of cellular technology, CDMA being one. The other is GSM (Global System for Mobile Communications). GSM is very popular in Europe and Africa, while CDMA is equally popular in Asia as GSM. CDMA has traditionally been more popular in North America, although in recent times, large network providers such as T-Mobile and Cingular using GSM technology have made GSM and CDMA fairly equal in the States (Sprint and Verizon use CDMA). A third technology, called iDEN, was used by Nextel but they have been taken over by Sprint and the technology is no longer used. 

 Because CDMA and GSM technologies are incompatible, one cannot use a GSM cell phone on a CDMA network or a CDMA cell phone on a GSM network. This is where it affects you and I as the normal person in the street, as we cannot use a cellphone that we bought on a CDMA contract on another type of network even if the phone was unlocked. 

 Recommended Samsung CDMA Phones (unlocked) 

 Samsung offers some great CDMA phones and GSM phones, but this article is interested in letting you know about the CDMA unlocked phones on offer at the moment, which include the Samsung SCH-r430, Samsung SCH-r500, Samsung SCH-r300 and the Samsung SCH-a870. All of these are unlocked phones which means they would work on any CDMA network. 

 All four of these phones are great for the middle-of-the range consumer who is looking for something to offer him or her reliability and some entertainment. The A870, in particular, has a wonderful camera phone that includes a flash. The R300 has two displays and is ideal for the person who enjoys browsing the internet. The R500 has a wonderful MP3 player for those who enjoy their music the most and the R430 is also a great camera phone with photo sharing applications.