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Multi-Network VS Multi-IMSI SIM Cards for IoT: A Comparative Analysis

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In the burgeoning world of the Internet of Things (IoT), connectivity is key. With an ever-increasing number of devices needing to communicate, the need for reliable and robust network solutions has never been more critical. Two of the leading solutions in this field are multi-network and multi-IMSI SIM cards. In this article, we will explore the differences between these two types of SIM cards, and the strengths and weaknesses of each.

What are Multi-Network SIM Cards?

Multi-network SIM cards are designed to provide seamless connectivity by connecting to multiple networks. These SIM cards can switch between different networks based on the strength and availability of the signal (unsteered), ensuring that the device stays connected in most situations. It is important to remember that from an IoT devices perspective, the most prevalent issue for ensuring connectivity is local availability of radio signal from a network. A multi-network SIM card provides the best chance of this being resolved in remote, oversubscribed or indoor locations.

Strengths of Multi-Network SIM Cards

One of the primary strengths of multi-network SIM cards is their ability to provide uninterrupted connectivity. By switching between networks, multi-network SIM cards can ensure that the device stays connected even in areas where one network’s signal might be weak or non-existent.

Additionally, multi-network SIM cards are easy to manage. They require less administrative work as they automatically switch between networks without needing manual intervention (IoT devices can provide more selective means via their firmware if needed; i.e. monitoring data or voice connections as well). They generally use one roaming network infrastructure. It is therefore vital that a high quality, geo-redundant and supported roaming network infrastructure is used.

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Weaknesses of Multi-Network SIM Cards

Multi-network SIM cards, however, also have a few weaknesses. For example, they are typically slightly more expensive than single or one network SIM cards due to the added functionality and resilience. This tends to expand as very large data requirements are needed., Also, in some countries, the availability of multiple networks or roaming agreements might be limited, reducing the effectiveness of these SIM cards in those areas.

What are Multi-IMSI (International Mobile Subscriber Identity) SIM Cards?

Multi-IMSI (International Mobile Subscriber Identity) SIM cards have multiple identities stored on the same card. They support multiple IMSIs which are provisioned onto the SIM cards in the form of multiple IMSI number(s), and can therefore select the best network based upon its profile and the geographical context. These identities can be switched depending on the location of the device, allowing it to connect to the local network and avoid roaming charges. They can be eUICC or eSIM or non eUICC. eUICC meaning supporting remote SIM provisioning (RSP) and non-eUICC meaning that they do not and are more proprietary in nature.

Strengths of Multi-IMSI SIM Cards

One of the main strengths of multi-IMSI SIM cards is that they can reduce costs by avoiding roaming charges, making them ideal for IoT devices that move between countries or are located in countries where permanent roaming is barred or roaming expensive. Multi-IMSI SIM cards can provide reliable connectivity in these instances, as they can switch identities to connect to the local network, ensuring that the device remains connected even when moving between different regions. They also by nature, have access to more than one core network. The usefulness of this to resilience, however, is dependent upon which IMSIs are usable in each country, their geographic coverage and relative costs for data and/or voice.

Further Reading:

Weaknesses of Multi-IMSI SIM Cards

Multi-IMSI SIM cards, however, also have some weaknesses. They can be complex to manage as the switching between identities needs to be managed and controlled. In some cases, the switching process may also cause brief interruptions in the connectivity. This is an important consideration. While a multi-network SIM card will use one core network roaming infrastructure to establish connections between different local providers, a multi-IMSI SIM card will need to switch core network as well to realise its full functionality.

For example, for a multi-network SIM to switch between local radio networks of different providers, a communication between the Home Location Register (HLR) of the core roaming provider and the Visitor Location Register (VLR) of a new local radio network is needed. In the case of an IMSI switch in a multi-IMSI SIM card, a connection to a new core roaming network is needed via its APN, meaning another layer of signalling in terms of authentication and network access. Devices and/or network infrastructure need to know the conditions for switching and the relative cost logic for avoiding excessive billing charges by making unnecessary switches.

The timing differential between switching local networks and core networks is open to much conjecture and will always be context driven. It is perhaps reasonable to suggest that timings can be anywhere between 20 seconds and 5 minutes for any of the scenarios discussed, depending upon the local network conditions and the device functionality.

The Power of Multi-IMSI, Multi-Network SIM Cards for IoT

Multi-IMSI, multi-network SIM cards combine the best of both worlds. A fusion of the two technologies discussed earlier, this type of SIM card combines the benefits of both multi-network and multi-IMSI SIM cards, offering a robust and versatile solution for many forms of IoT connectivity.

What is a Multi-IMSI, Multi-Network SIM Card?

A multi-IMSI, multi-network SIM card has multiple roaming network profiles and multiple International Mobile Subscriber Identities (IMSIs) stored on the same card. This allows the card to switch between different roaming or local network profiles and IMSIs based on the location and strength of the network signal.

Strengths of Multi-IMSI, Multi-Network SIM Cards

The primary strength of a multi-IMSI, multi-network SIM card lies in its flexibility and robustness. With the ability to switch between multiple networks and identities, these SIM cards can provide reliable, uninterrupted connectivity in a wide range of situations.

This type of SIM card is especially useful for IoT devices that move between different regions, such as the case with large scale manufacturers. It can connect to the local network in each region, avoiding roaming charges if a native profile or a preferred roaming profile is present, ensuring that the device remains connected even in areas where some roaming networks may not be available or prohibitively expensive.

Furthermore, these SIM cards can provide a backup in case one network fails, automatically switching to another available network. This ensures that your IoT devices maintain steady connectivity, which is especially crucial for applications where continuous data transmission is required under all circumstances.

Further Reading:

Even further reading: rSIM – The intelligent, resilient multinetwork, multi-IMSI SIM card by Caburn Telecom & The CSL Group): rSIM, the world’s first resilient IoT SIM Card

Weaknesses of Multi-IMSI, Multi-Network SIM Cards

The main challenge of using multi-IMSI, multi-network SIM cards is their complexity. Managing the switching between different networks and identities can be complex and requires a robust management system.

Another potential downside is cost. These SIM cards can be more expensive than traditional single network or single IMSI multi-network roaming SIM cards due to their added functionality, profiles and capabilities. This cost, however, can be more than offset by the potential savings from avoiding roaming charges and the value of having reliable, uninterrupted connectivity.


Both multi-network and multi-IMSI SIM cards offer unique benefits for IoT connectivity. The choice between the two depends on the specific needs of your IoT devices. If uninterrupted connectivity is a priority, a multi-network SIM may be the best choice. On the other hand, if your IoT devices frequently move between different regions, a multi-IMSI SIM card could provide cost and connectivity benefits.

The multi-IMSI, multi-network SIM card also represents a powerful tool in the IoT connectivity toolbox. It combines the strengths of both multi-network and multi-IMSI SIM cards, providing a versatile and reliable connectivity solution for a wide range of IoT applications. As with any technology, it is important to carefully consider the specific needs and cost structure of your IoT devices and the environment they will be operating in when choosing a connectivity solution.

At Caburn Telecom, we understand that every IoT project has unique needs and requirements. Our team of experts can help guide you to the best SIM card solution for your project, ensuring that your IoT devices stay reliably connected wherever they are.

We are committed to delivering tailored connectivity solutions that meet the unique needs of your IoT project. With our expertise and experience, we can help you navigate the complexities of IoT connectivity and choose the most effective SIM card solution for you.