Originally Posted by Auspicious
Most of the world uses GSM for cell phones. There are 1.5billion GSM phones around the world. Some countries use CDMA. There are about 300million CDMA phones around the world. Some countries that use GSM also have CDMA support in major metropolitan areas specifically for business travelers and tourists. GSM and CDMA are incompatible technologies.
frequencies used vary. In most countries one or two of 800, 900, 1800, and 1900 MHz are used.
The US is the only country I am aware of that does not have a clear standard. AT&T and T-Mobile use GSM. Verizon and Sprint use CDMA.
For global traveling my recommendation (and my choice) is a quad-band GSM phone (so all four sets of frequencies are supported and the technology matches most of the world). You can choose between an international roaming agreement which is dead easy but can get a tad expensive or getting an unlocked phone.
I have an iPhone
(which is a quad-band phone) set up for international roaming. When I get into port or step off an airplane it just works. I also have a Motorola Razr V3 (the older ones are quad band) that AT&T gave (free) me the unlock code for. I buy a local pay-as-you go SIM card anywhere I'll be for more than a day or two. Anyone anywhere can reach me on my US phone number, but for local calls and international calls out I use the local phone with the local number.
My solution may not work for you, but you will be hardpressed to find a better approach than an unlocked quad-band GSM phone to manage your voice communications needs in port.
This is the standard solution for world travellers, whether on water
or not. I go one step further and carry a dual SIM card Samsung phone in addition to my quad-band Nokia E90, so I can have three SIM cards online at once. You just buy a local pay-as-you-go SIM card when you arrive in a new country and send SMS text messages with your new number to everyone who needs to be able to reach you. Often the SIM card is even free. It is free to receive calls on GSM phones almost everywhere except US and some Caribbean countries, and the most useful communications feature of all may be SMS, where you can send and receive text messages to any other GSM user in the world for peanuts.
There are also services which you can set up to forward your home mobile number to whatever temporary number you're using somewhere else, to avoid the often extortionate roaming charges. Globaltel is one I have used and can recommend.
I have a UK -pay-as-you-go SIM card from T-Mobile. I get unlimited high speed internet wherever I might be for something like 10 pounds per month, plus I can call just about any place in the world outside of the EU for 5 pence a minute, including the US, Russia
, etc. To call inside of the UK or EU is more expensive, but receiving calls is free. And I can use it all over the EU because of the roaming cost controls there. It's great. It is a total telecommunications solution for me all over Europe
-- when I'm in range of an HSDPA (3.5g) tower, I have DSL-like internet.
For the US, I have an AT&T account with unlimited internet.
I have a nice collection of SIM cards from other countries in a little pocket in my passport case.
Man, has it gotten easier to communicate when travelling.
Now that the GSM network has been fully built out in the US, any American who travels at all will want to be on one of the GSM carriers (ATT and T-Mobile); you cannot travel very far with the non-GSM solutions (Sprint, Verizon, etc.).