As citizens of the US travel internationally for business and pleasure, the question of using their cell phone during their trip often comes up. A cell phone can be extremely useful when landline phones aren't readily available or when the traveler wants to be easily accessible to family, friends, or their employer while away. Experienced travelers know that simply packing up their US based cell phone to take along is often not enough.

Unfortunately, cell phones/cell phone services in the various countries can use different types of radio frequencies and encoding. While in the majority of European, Asian, and African nations GSM is the standard, this is not so in the US, Canada, Australia and a few other countries where other networks might also be used. Obviously, the cell phone that a traveler uses must be able to communicate through the network in the country they are visiting. In addition, the cell phone must be able to operate at the proper frequencies. Most US networks use different frequencies than those used abroad.

There are a few options for travelers in assuring that they have a compatible cell phone but probably one of the more affordable is to purchase an unlocked GSM cell phone or an international/world phone. T-Mobile and Cingular are the largest providers of GSM phones in the US but an online search will also reveal other specialty suppliers. Travelers need to be sure that the phone they purchase will operate at the frequency needed. Quad-band phones are available that operate at the four most common frequencies used in the US and abroad.

Travelers can check http://www.gsmworld.com/roaming/gsminfo/index.shtml to determine what frequencies are used in various countries around the world.

It is possible for travelers to use International Roaming if they simply have a GSM cell phone that will operate on the appropriate frequency and their US plan has international roaming available. This tends to be a rather expensive option and it is necessary to assure that service can be provided from the destination as the US provider would need to have a cross-billing agreement in place to assure roaming is possible. Again T-Mobile and Cingular would be the best bet for these types of services.

If a traveler wants to avoid some of the more highly priced International Roaming charges they can obtain an unlocked GSM phone or world phone and install a SIM card which is compatible with the service in the country they will be visiting. Service in the country of destination would then need to be purchased, but luckily it is often possible to purchase a set number of pre-paid minutes to use rather than committing to a lengthy agreement or monthly plan. As with any purchase it is wise to compare pricing of the various options and to become knowledgeable about fees and what will and will not be covered in the pre-paid minutes. On the upside for US travelers, most other countries do not charge cell phone users for incoming calls.

Once a traveler has a compatible GSM phone, SIM card, and service is arranged then they are set to be able to make and receive calls while away. Before boarding the plane however, it is also important to remember to take along an appropriate adapter to assure that the new phone can be charged when needed.