ukraine roaming costs

How Does Data Roaming Work: A Technical Perspective

Data roaming is a term many travelers are familiar with, but few understand the underlying technical aspects that enable this service. How Does Data Roaming Work

SIM card e SIM shop

This article provides a comprehensive look at how data roaming works from a technical perspective.

What is Data Roaming?

Data roaming refers to the continued data service you receive when you go outside of your mobile operator’s coverage area. In essence, you “roam” onto the networks of other operators. But how does this process work? Let’s break it down.

The Technicalities of Data Roaming

Understanding data roaming requires a basic grasp of how mobile networks operate. Here’s a simplified explanation:

  • Home Network: This is your mobile operator’s network, where your data services are typically used.
  • Visited Network: When you travel outside your home network’s coverage, you connect to a visited network. This network may belong to a different operator.

When you use data services while connected to a visited network, your device communicates with your home network to verify your identity and ensure you have the necessary roaming privileges. This process involves several key components:

  • Mobile Switching Center (MSC): This is the component of the visited network that your device first communicates with. The MSC is responsible for routing calls and data.
  • Gateway GPRS Support Node (GGSN): The GGSN acts as an interface between the visited network and the internet. It requests data on your behalf and sends it to your device.
  • Home Location Register (HLR): This database in your home network contains information about your subscription services, including whether you’re allowed to roam.

The Roaming Process

When you turn on your device in a foreign country, it sends a signal to the local networks. One of these networks (the visited network) accepts the signal and communicates with your home network to verify your identity and roaming privileges. Once verified, you can access data services through the visited network.

Data Roaming Charges

Data roaming can be expensive because your home operator has to pay the visited operator for the use of their network. These costs are typically passed on to you as roaming charges.

The Future of Data Roaming

With advancements in technology and changes in regulation, the future of data roaming looks promising. For example, the European Union has abolished roaming charges for its citizens traveling within the EU, making it easier and more affordable to stay connected while traveling.


Understanding how data roaming works from a technical perspective can help demystify this often confusing aspect of mobile communications. As technology continues to evolve, we can anticipate further improvements in data roaming services, making it easier for travelers to stay connected wherever they go.

Here are some indicative prepaid eSIM card prices: eSIM Activation

Europe (30 countries)
1 GB – no exp. –  €3.70
3 GB – no exp. – €10.77
10 GB – no exp. – €33.30



Europe (39 countries)
1 GB – 7 days – €4.53
3 GB – 30 days – €12.00
10 GB – 30 days – €33.40airalo



Europe (29 countries)
500 MB – 1 day – €2.00
3 GB – 30 days – €8.00
10 GB – 30 days – €19.00



Europe (36 countries)
1 GB – 7 days – €6.50
3 GB – 15 days – €11.00
10 GB – 30 days – €20.50



Stay ahead of the curve in mobile connectivity by following all the latest and most important eSIM news.

Like this? "Sharing is caring!"