M2M National Roaming ensures uninterrupted data transmission by giving your devices access to multiple mobile networks within a country. If a network fails or the connection is unstable, the M2M SIM card automatically switches to the strongest available network - without manual intervention.
Ideal for IoT and M2M applications such as smart metering , telematics or industrial automation.
The IoT trend is currently growing like never before. The Internet of Things (IoT) is constantly expanding, and more IoT devices and objects are being connected every day. This also includes the provision of associated information via machine-to-machine (M2M) communication within a network. However, in order for the data collected by IoT devices to be processed in a network, they must first be transmitted to that network.
This is where mobile communications and our M2M SIM cards come into play. Collected data can be transmitted quickly and securely from any IoT device via mobile communications. Mobile communications is an established and standardized technology, and the infrastructure is available almost everywhere —not just in Germany, but worldwide. This is why mobile communications are so frequently used for M2M communication.
The key point here is that nationwide availability, especially in Germany, is not achieved by a single network operator, but only by the mobile networks of all network operators together.
According to the Federal Network Agency (article accessed on March 10, 2025), there is still a backlog in the network coverage of individual network operators: Approximately 2 percent of Germany's total area is not yet covered by broadband mobile network coverage. Deficits remain, particularly in rural areas, and in some regions, only the network of one mobile operator is available. The individual available operators, in turn, vary from region to region.
This patchy coverage still demonstrates the relevance of using appropriate M2M SIM cards for IoT and M2M projects.
Unlike the SIM card from a private smartphone, an M2M SIM card can also use the networks of different network operators within a country, i.e. perform national roaming. M2M SIM cards are therefore also known as roaming SIM cards or multi-network SIMs. National roaming is possible because we, as a provider of M2M SIM cards, have concluded roaming agreements with various network operators. These agreements allow our M2M SIMs to connect to the networks of our contractual partners.
Not all national roaming is created equal. There's a small but important distinction here, which is very important for IoT and M2M projects. These are controlled roaming and uncontrolled roaming .
With our SIM cards, it's not the network operator that counts , but solely the strength of the available mobile network at a given location. With our M2M Roaming SIM, you use uncontrolled roaming . This is important because the availability of a mobile network varies depending on the location: Sometimes one provider's network is strongest, sometimes another's. If a provider issues M2M SIM cards themselves, these are usually based on the network provider, not the network strength.
In concrete terms, this means that if provider V issues a SIM, it will always try to connect to provider V's network first—no matter how poor the connection is on their network. Only when provider V no longer offers a network can the IoT device log into another mobile network.
Prefers the provider's network operator
Regardless of the network strength, always give preference to the provider of the device
Stays in the mobile network of your own provider, even with a poor connection
Selects the mobile network based on the best local connection
Network change depending on the strength of the locally available mobile network
Switch to another provider if their network is better
No network independence, network change only in the event of failure of own provider
Full network independence, devices can choose the best network
Often with SIM cards issued by the network operator itself
Often for flexible IoT or M2M solutions that rely on the best network coverage
