In the last couple of years many different frequencies have been added to the confusion of the worldwide GSM (2G/Edge) and High Speed Data Networks (3G,HSDPA,UMTS) on cellular phones. Since we all love to have the newest gadgets we would like to be one of the first. In the Windows Phone forums, where I moderate, many questions arise why my phone bought overseas is not connecting to the high speed data service in a specific country. Hopefully I will be able to guide you below to the answer and give you the specifics before you purchase your next Unlocked Phone to use at home or world wide.
Well, many mobile devices are specially engineered for the different markets around the world. For example the HTC Touch Pro and the HTC Fuze are exactly the same device, however the build in radio’s for the 3G / HSDPA data network are different. When you travel overseas you can loose this high speed data signal and fall back on the Edge/GSM/GPRS/ 2G network. Many people like to purchase an unlocked phone overseas and bring it back to their home country and then they realize that the 3G / HSDPA radio’s build into the device are not supported.
Why high speed data? The mobile phones these day are more like small personal computers. They are more and more being used now for streaming media content (Internet radio and TV), Internet browsing, etc. over the high speed data networks. You even see that other non-phone mobile devices will have 3G build in to give the device the opportunity to download information at high speeds when needed. For example the Kindle 2 and DX from Amazon and many Netbooks are sold now through the mobile phone service providers with the High Speed 3G / HSDPA data connection.
Many phones these days are called “World Phones”. These phone most likely will support the High Speed Data Networks (3G,HSDPA,UMTS) world wide. However I would still look at the specifications of these phones before you purchase and balance them to the network frequencies in the area you live.
The GSM (2G/Edge) frequencies are often called Quad Band Phones. Most phones will work worldwide using these 4 frequencies for making calls and limited data connection. These frequencies are:
Below is a small table giving you the frequencies in High Speed Data Networks (3G,HSDPA,UMTS) with their known regions that these frequencies will work. Use this to make sure the phone you will purchase will work with the high speed data frequency connections you need. Please note that you need a data subscription with your mobile provider carrier before you can have data on your device.
3G,HSDPA,UMTS high speed network frequencies and their regions.
850 MHz (United States AT&T)
1700 MHz (United States T-Mobile)
1900 MHz (United States AT&T)
2100 MHz (Europe)
There are many other resources online to see which frequencies you have in your area. These tools will allow you to make an educated decision which unlocked phone and where you would like to purchase it from and if it will provide the services you want to have in your part of the world.