What is a World Phone?

Such a seemingly simple question but one which does not have a universal definition. The simplest definition would describe a world phone as a cell phone that will work anywhere in the world (for the purposes of this discussion we will ignore satellite phones which work where there is no cell phone network coverage). However, the phrase “work anywhere in the world” is somewhat vague and in need of further consideration.

Firstly we have to consider that a cell phone is in fact a combination of the phone itself (or handset) and the SIM card inside. For a phone to work everywhere it must operate on a frequency that is supported by networks around the world. In the US, the CDMA network and frequencies are common but in the rest of the world it is the rival GSM frequencies that are most commonly supported. For a phone to be genuinely worldwide it ought to be at least tri-band (supports 3 frequencies and typically these would be 900/1800/1900 Mhz).

We must then consider the SIM card. The SIM card gives the phone a number and belongs to a single phone network from one country. Most SIM cards are designed primarily to be used in their country of origin. So a Sprint or Verizon SIM card will work well in the US and provide good low cost calls. It is possible to take the handset and SIM abroad and in most cases this will continue to work. The phone is now “roaming” and it will connect to foreign networks to allow calls, SMS and data. Some providers may bar roaming by default and require this bar lifting and the reason for this is the same reason an iPhone has the “Data Roaming Off” switch – roamed calls and data can get very expensive very quickly.

So where does a World Phone come in? What magic property does it have to make it ideal for a global traveler? We’ve already established that the handset must be compatible with the world’s networks but what really makes a world phone a world phone is the SIM and tariff provided by the network. A number of networks around the world produce a SIM card which is designed specifically to be used in many other countries. The SIM still comes from a single country (e.g. the UK), and still has a single phone number (e.g . a +44 number for a UK SIM card). However, the costs for roamed calls and data are much-reduced making it a cost-effective card to use around the world.

This solution typically comes with a small monthly fee and it won’t be as cheap as using a domestic SIM card in each country (e.g. a Spanish SIM in Spain then a German SIM in Germany) but it will be considerably cheaper than using a US SIM in those countries whilst roaming.

There is one further consideration – an international SIM card of this nature may be optimized for calls back to one country. So, for instance, a solution intended for the US market may make calls back to the US better value than calls to, say, China. A solution intended for a UK market would make calls back to the UK as cost-effective as possible at the expense of calls to other countries.

So to summarise, to be genuinely termed a “World Phone” a cell phone must have

  • A handset that supports GSM and ideally is tri-band or quad-band (frequencies)
  • A SIM card with a tariff/plan designed to be used roaming across the world at reasonable cost
  • A SIM card that has call costs optimised for outgoing calls back to your country of origin

To buy a World Phone click here


CDMA vs. GSM: What’s the difference?

What is CDMA?

CDMA which stands for Code Division Multiple Access is primarily used in the U.S. and small regions of Asia. Each handset is tied to a particular network (such as Sprint or Verizon).

What is GSM?

GSM which stands for Global System for Mobile [communications] and is the world’s most widely used phone technology. Approximately 80% of the world uses GSM technology when making wireless calls, this equates to almost 3 billion people using the technology.

GSM has the advantage of using a SIM card which is tied to a particular network (such as T-Mobile or AT&T) rather than the handset being tied to the network. This allows users to move networks with their existing handset by swapping the SIM. Some handsets are ‘locked’ by the network on a post-pay contract, but can almost always be unlocked on request.

International Cell Phones

For practicality GSM offers the widest international roaming capabilities. GSM can be used in over 138 countries worldwide, compared to CDMA which can only be used in 2 countries worldwide. This makes GSM the perfect technology for traveling.

With CDMA the user would need to purchase a separate GSM European cell phone or international cell phone specifically for traveling as CDMA handsets work only in limited countries. With a GSM handset no additional purchase is necessary, it is possible to continue using it while roaming internationally in most countries. However, this can be expensive and a much cheaper alternative is local SIM card rental. Simply swap the U.S. SIM for an international SIM rental and a user can carry on using their handset as normal at greatly reduced call rates.