Last updated: 2004.10.26

Global Roaming with one Cellphone

The world is getting smaller. As you travel from one part of the world to another, it would be really nice if your single cellphone works in each of the country. Right? Well -- it is almost that easy now, primarily because of GSM. First, divide the developed world into three parts:

Europe, UK, Asia (except Japan and Korea)

This is the easy part. All these countries use GSM as their wireless phone network. A phone from any one of these places will work in the others -- as long as you have the right dialing and roaming plan. The list of country on this listcan be found at here at

Hong Kong

  • Buy a prepaid card at any of the Orange store
  • Buy it from a vending machine !!

United States

The US, in typical US fashion, have several in-compatiable networks from different carriers (Voicesteam, AT&T, Sprint, etc). The only network that is close to the rest of the world is the America version of GSM. It is GSM, but the frequency is different -- PCS1900 instead of the normal 1800/900.

Luckily most vendor build at least one phone that works with both normal GSM and American GSM. These phones are called world phones, or tri-band phones. The name tri-band is technically inaccurate but that is too much unnecessary detail.

Currently T-Mobile (formally Voicestream) in the U.S. offers GSM plans. AT&T started to also, but their network coverage may not be as good.

Japan and Korea

Japan, in typical Japanese fashion, have their own standards and networks. However their NTT network with DoCoMo or i-mode is really cool and they are introducing the i-mode part of that into Europe right now. The are sold under e-plus/i-mode in Germany. So there is no way for you to use a world phone in Japan. However you can rent a phone while you are travelling in Japan. Buying a phone and service is difficult because they do not like to sell phone service to non-resident. But it is getting easier. Currently I use JCS Rental services which you can rent a phone on the web (from the US) and have it deliveried to you to your hotel or pick up at Narita airport.

Korea is similar to Japan in that they have their own network.

One Phone and Provider Roaming

So if you need to travel between just Europe, UK and Asia you just need a GSM phone. If you add to that list the United States, you need to get a world phone. If you add to that list Japan you have to rent a phone in addition to your own phone. Note that if you just use your home country based service provider (Voicestream in the United States) you get to keep the same number. However the roaming and internationally calling can get quite expensive.

Plastic Roaming

The easy way to roam globally cheaperly is to buy a different SIM card for each country.You will not have the same phone number of course, the it is cheaper when making local calls, and often get a cheaper rate then, say the US rate.


Let's talk about only Nokia phones here, since they do make the best phones (my personal view of course). Nokia phones use a numeric scheme to label the different models. Models with the 90 suffix, i.e. xx90, are the GSM phones. Not all of them are tri-band. The 8290 -- a very good phone, only supports PCS1900 and only works in the US. You need the 8890, which is their dual band (GSM900/PCS1900) world phone. You can read my review of the Nokia 8890 here.