The Global System for Mobile Communications, known as GSM for short, provides cell phone technology and services all over the world. Cell phone companies either use GSM or CDMA, and which company they pick says a lot about the service they provide. GSM is known for its international calling, and these phones are best for those who plan to travel internationally a lot or who change cell phones often. CDMA is best for users who do not need to change phones when traveling and do not switch cell phones often.
Each cell phone, or wireless phone, includes a SIM card which registers a phone number and other identification information to that particular phone. The factory locks the phone so the SIM card will only work in that specific wireless phone. If a user can unlock a wireless phone's SIM card, or buy a phone already unlocked, then she can switch that card to a new phone and the new cell phone will think it's still the old one. This is especially helpful when traveling to a foreign country or buying a new phone. Switching the SIM card allows the user to keep paying for her original service while using a new phone, or use a SIM card with low rates in a foreign country in her current phone.
When choosing a GSM wireless phone, check which companies use GSM. It's important to look into the different phone types available through these providers. A customer who keeps track of appointments and checks her e-mail on her phone will want a smartphone, while a customer who only uses her phone for calls may opt for a cheaper model.
Next the customer will need to know how often she plans to travel and from what countries she'll use her GSM wireless phone. GSM phones transmit on a number of bands, such as dual-band, tri-band, or quad-band. Each one operates on different frequencies and certain phones can operate on more frequencies than others. When a user travels to a different country, she'll need a phone that operates on the frequency used in that country.
Quad-band GSM wireless phones are the best choice for anyone traveling to several different countries. It works virtually anywhere in the world and picks up on four frequencies. The dual-band GSM wireless phone covers South America, New Zealand and Australia, Africa, and Europe and Asia. The tri-band GSM wireless phone covers the same countries as the dual-band except it covers North America instead of South America. For best results, it's important to choose a phone with the needed coverage areas.
Once usage details are decided, customers should look for a company selling unlocked GSM wireless phones. If the phone is locked, it defeats the point of buying a phone to travel with internationally. The customer may also want to check where she can buy SIM cards to use when traveling. After finding a company that offers the right phones, the last check is to see that the phone has all the desired features, such as voicemail, a camera, or Internet connections.