What is international roaming?
When you travel to a foreign country and you can still talk from your phone and surf the web – that’s roaming. Roaming ensures that your mobile phone remains connected to a network and gives you the ability to make use of a host network, other than your parent network. But what is international roaming?
While you travel abroad, your mobile phone connects to a visited network, which allows you to automatically make and receive voice calls, send and receive SMS and data or access other services from anywhere in the world.
To better understand it, imagine that you fly from country A to country B. When you cross the border between the two countries, as long as you have roaming services enabled, your mobile will automatically connect to one of the available mobile networks from country B. Once you connect to a host network you can make and receive calls, SMSes and surf on the internet.
Types of roaming
There are two types of roaming: national and international roaming. National roaming refers to changing mobile operators within the same country. On the other hand, international roaming is the type of roaming we are examining. Both types of roaming are divided into two types of roaming: voice and texts and data roaming.
So how does roaming work?
How does roaming work?
When your mobile phone is ON, it automatically tries to connect to a network. Since it can’t connect to the parent network, it’s looking for a host network. To be able to do that, the host network is asking for certain information from the parent network. As soon as it receives the information and authorization, it connects to the host network. The host network will then forward everything to the parent network.
Therefore, for roaming to take place, two conditions must be met:
- An existing network in a foreign country
- The collaboration between the foreign network and yours (roaming agreement)
This collaboration between the networks enables:
- The signalling connection, which allows mobile signals to be transported back and forth between the operators
- A data pipe, which allows you to use data and Internet services
- The exchange of information between calls made in the visited network (call length, rates, etc).
- The management of all roaming-related financial transactions between mobile operators
Keep in mind that regardless of the network you are connected to, you have a unique number, the MSISDN. Every user in any network has an MSISDN.
What is MSISDN?
According to Techopedia, MSISDN stands for Mobile Station International Subscriber Directory Number.
Thanks to that assigned number, the network can tell where the phone call is coming from: namely, which operator, which country and which user. Accordingly, MSISDN includes a country code and a National Destination Code which identifies the subscriber’s operator.
Cheaper data roaming
Roaming can be expensive. If you communicate a lot while abroad, it can cost you a small fortune. Many smartphone owners decrease their data usage for that reason.
To keep your costs down, you can ask your service provider about roaming charges for the country you are visiting. You may also consider buying an international data package which makes roaming much cheaper.