What mobile operators are not telling you

There are currently two main mobile technologies being used around the world: one is called GSM (Global System for Mobile Communications), which is used on every continent worldwide, with approximately 1.1 billion subscribers and the other is called CDMA (Code Division Multiple Access), which is used mainly in the Americas and parts of Asia with approximately 200 million subscribers. Although both systems allow people to perform similar functions like making phone calls, sending text messages (SMS) and using services like email, the techniques used by the two systems are so different, that if a person on one network tries to communicate with a person on the other (outside of a simple phone call), they may encounter problems.

There are two keys to for knowing if the life-or-death text message you just sent has gotten through to its intended recipient: the first is to know your operator’s network and the second is to understand your phone.

Knowing what kind of network your mobile operator is running on will help you figure out with whom you can communicate with using your operator’s services, and where you can connect to when traveling abroad. To keep you connected, the operator needs to keep track of your phone, which is identified by a phone number stored on a SIM card in your phone. SIM cards are used if your operator runs on GSM. This memory card, which is the size of your thumbnail, is usually placed under the battery of your phone.

If the phone doesn’t use a SIM card, then the phone number is stored directly inside the phone, in which case, the network in use is likely to be CDMA. You can also ask your operator or perhaps a mobile retail shop for this information if you want to be 100% sure.

Aside from providing operator information, retail shops can be helpful with providing information about phones, which takes us to the next step. What you’ll be interested in knowing is the type of bands, or radio wave frequencies your phone can communicate on, because this will help determine where your phone will work when traveling abroad. To explain in simple terms, think of each band as a highway for different vehicles. The more bands your phone is capable of dealing with, the better your chances of reaching your destination. Most phones are either dual-band or tri-band, but there’s no easy way of knowing which it is without looking up the instruction manual, asking a mobile phone salesperson, or checking the phone manufacturer’s website.

Local mobile service

Once you know what kind of network you’re on, you can more-or-less be confident that your communications efforts will get through to other people that are using the same kind of network in your region or country, regardless of the operator.

Let’s take a real-world example. In a European country like Switzerland, all the operators run on GSM networks (thus, all phones use SIM cards.) This means a person using the operator Swisscom is able to to make phonecalls, send text messages, chat, or use almost any service to connect to another person using Sunrise - or Orange, or any other operator in Switzerland and most times, to any user in the world using the GSM network.

But when we consider countries where operators run on three, four or even five different types of networks like in the United States, sending a simple text message to a friend can be a problem even if both people are using the same operator. For example, a person using the GSM operator T-Mobile can send messages and use other services to connect to other people using T-Mobile, but may have problems when trying to send the same message to someone using CDMA operator Verizon, and have partial success when sending to a person using AT&T mobile, because AT&T runs on more than one type of network. Successful sending of the message may depend on which AT&T network the receiver of the message is using. Outside of making phone calls, the simplest way of guessing your network’s compatibility with your friends’ is to ask if they have a SIM card in their phone. If both of you have one (or if both of you don’t), the chances are, you are on the same system. Sending a text message to each other should then confirm compatibility if the message is received.

Going global

To find out whether or not you can stay connected while traveling to different countries, just remember the two keys to better connectivity. First, check your operator’s capabilities with roaming. Many, but not all mobile operators will have roaming agreements with operators of other countries. What this means for you is that you could be traveling to Spain or Greece on holiday and your phone would still work by roaming via the local Spanish or Greek operator. Ask your operator about the costs of roaming because phone calls and text messages are priced differently when you’re abroad.

Next, let’s take a look at the phone. So far, the phone’s band capabilities haven’t played a big role, but once you start to roam, bands become a very important issue. Operators in most countries run between one and three bands. On GSM networks, the Americas run on 1900 band, while most other countries outside of the Americas run on 900 and 1800 bands.

In practice, this means that if you have a dual-band GSM 900/1800 phone, the phone will work on most networks in Europe, Middle East, Africa and Asia. If you have a tri-band GSM 900/1800/1900 phone, it can connect almost anywhere in the world, except in countries like Japan and South Korea (these countries use other technologies.)