The not so obvious truth about multi-network SIMs.

When every byte of data has the potential to impact critical actions and decisions, the stakes for maintaining an uninterrupted link to the IoT are high. With vital reporting so often at stake, the difference between a stable connection and a lost signal may be the difference between seamless operation and catastrophic failure.

For IoT resellers and managers of large estates of devices, the choice of connectivity solution is not just technical – it is strategic. Among the various options, multi-network SIMs are widely seen as the optimal choice, apparently promising the ability to switch between networks to maintain the best possible signal. But delving deeper into the reality of how these SIMs operate, raises question about their efficacy and reliability.

The appeal of unsteered multi-network SIMs is undeniable, with the promise of liberation from the constraints of single-network dependencies, and the prospect of devices connecting freely to the strongest available signal. But beneath this lies a complex, often misunderstood mechanism of network selection which can lead the unsuspecting into a quagmire of connectivity issues.

As an MVNO providing connectivity in this space, we are well placed to help unwrap the complexities of unsteered multi-network SIM connectivity, and shed some light on the intricate process of network selection and its implications. Doing our best to ignore the ‘glossing over’ to which marketing can be prone, our aim is to offer a clearer understanding of what actually happens when a device searches for a signal, and why an alternative approach might well serve your connectivity needs better.

In considering this issue, it’s important to keep in mind the critical role connectivity has in the IoT ecosystem. Every device, from the simplest sensor to the most complex machinery, relies on a stable and strong network connection to function as intended. In the intricate ecosystems of digital communication, where each step is meticulously balanced and intertwined to ensure harmony and efficiency, the choice of how your devices connect is probably the most pivotal decision of all. So, let’s take an informed and critical look at the promises, the realities, and the alternatives that might offer a better path to seamless, reliable connectivity.

Understanding multi-network IoT SIMs.

As we said, connectivity is the lifeline that ensures the seamless operation of IoT devices. From agriculture using smart sensors to optimise crop yields, to healthcare leveraging wearable technologies for patient monitoring, the demand for reliable, uninterrupted network access is already huge, and growing by the minute. At the forefront of addressing this demand are multi-network SIMs – solutions designed to ensure that devices stay connected by dynamically switching across different mobile networks. But what exactly are they, and why do they have such appeal in the market?

The understandable appeal of multi-network connectivity.

Multi-network SIMs do offer a compelling value proposition: the ability to connect to multiple mobile networks without being tethered to a single carrier. This capability is especially crucial in scenarios where network coverage is variable or where devices are mobile, operating across areas serviced by different network providers. The theoretical advantage is clear: by always selecting the best available network, these SIMs will be able to enhance the reliability and efficiency of IoT operations, minimising the risk of disconnections and operational disruptions.

However, the choice between using a traditional single-network SIM and opting for a multi-network solution is not solely about the availability of network diversity. If we are to avoid object-defeating loss of performance, a deeper understanding of how these SIMs operate, their configuration (steered versus unsteered), and the implications of these choices on connectivity quality and operational costs is required.

Steered v Unsteered: the vital difference.

At the heart of the multi-network SIM conversation is the distinction between ‘steered’ and ‘unsteered’ configurations. Steered SIMs are programmed to prioritise connection to a ‘home’ network, potentially offering the more stable connections and cost benefits associated with predetermined agreements with network providers.

Conversely, unsteered SIMs are designed to latch onto any available network, ostensibly providing greater coverage flexibility, but with caveats regarding signal quality, cost, and data sovereignty. This distinction raises critical questions. While the allure of unsteered SIMs lies in that promise of universal connectivity, the reality of how these SIMs select networks – and the potential for suboptimal connections – merits rather closer examination.

Unwrapping the network selection process.

Understanding how unsteered multi-network SIMs make network selection decisions is key to assessing their suitability for IoT applications. Contrary to the marketing narrative of seamless connectivity to the “strongest” available signal, the actual selection process is governed by a series of predefined criteria set by the 3GPP standards.

This process, which ranges from attempting to connect to the last known network to evaluating available networks based on signal quality, reveals a more complex and less discriminating approach than expected. For instance, and in spite of the promises, the criteria do not guarantee connection to the network with the highest signal quality. Instead, the process can result in connections to networks offering merely adequate signal strength, potentially compromising connectivity performance.

This reality is in contrast to the expectations set by the term “strongest signal,” and it means that the benefits of unsteered SIMs are not as straightforward as they appear.

/contd.