One thing that we most often get questions on at PureMobile is regarding the GSM network and what it is. The reason is there are two networks CDMA and GSM. The main difference to find out which you have is locate the sim card, a small chip in the phone that contains all your information. If you have this card then you likely have GSM. Now we say likely as some carrier’s like Sprint have a walkie-talkie type network (NexTel) and they use a “sim card” but it’s for Sprint’s CDMA network.
GSM phones can be unlocked because the sim card can be removed and placed into another phone without having to call the carrier to activate it. CDMA needs to have each phone activated by the carrier on the network to operate. This limits the phones you can use.
Another difference is that GSM phones are much more widely available. GSM networks are found throughout the world. They each use different bands but they are all GSM. CDMA can be found primarily in North America and a few other countries.
As we just mentioned GSM use bands or frequencies. There are four frequencies that are used most frequently. They are the 850 MHz, 900 MHz, 1800 MHz and the 1900 MHz bands. In North America the two widely available are the 850 MHz and the 1900 MHz.
So the question is which type of phone should you choose? Well it depends on where you plan on using the phone. If you are going to use it in North America then you can simply get any phone that uses the 850 MHz and 1900 MHz bands and you should have no problems. If you plan to travel then you would be best to get a quad band phone, which is a phone that can work on all four of the bands. This gives you the least chance of running into a problem with no signal.
More and more phones these days are coming as quad band phones so you don’t have to limit yourself. You can get one phone and use it the world over.