Cellular eSIM Connectivity for IoT Applications: Frequently Asked Questions

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The machines we use to run our businesses are increasingly connected—and these connections are increasingly happening on cellular networks. By 2025, there will be as many as 5 billion IoT devices exchanging data on the same systems that connect our smartphones, predicts Ericsson. The mobile network operators (MNOs) that operate these networks have always needed a way to identify, authenticate, and secure interactions with valid users. Since the early 1990s, they have accomplished this task with subscriber identification module (SIM) cards. That’s true for the machine-to-machine (M2M) protocols that power the industrial IoT as well as consumer IoT products, from e-scooters to smart fridges. Each SIM card is preprogrammed with a unique operator identifier and authentication codes, then shipped to the user. If you want to change an IoT machine’s operator, you have to swap out the SIM card. You have to do the same to switch network carriers.  In this era of cloud computing, that’s hardly an ideal scenario—hence the drive toward embedded SIMs (eSIMs).

These eSIMs are hard-wired into the mobile device and when combined with the software component, called eUICC, allow for remote provisioning, or changing MNOs and operator credentials over the air—that is, through the cloud, without physical logistics trains. As attractive as this is for IoT users and device manufacturers alike, questions remain. Are eSIMs really secure? Will MNOs support them in all markets? Is this really a transformative technology, or is it all hype?    

Whether you’re an IoT device manufacturer or a business moving toward a more connected workplace, this FAQ covers some of what you need to know as you consider adopting eSIMs.  

What Makes Cellular eSIM Technology so Valuable? 

There’s a lot of excitement surrounding eSIMs. Why all the buzz? This technology addresses some serious challenges associated with traditional SIMs. The advantages of cellular eSIM technology break down differently for manufacturers of IoT devices and their users, although there are plenty for each: 

eSIM Advantages for Device Manufacturers

  • Global deployment of IoT devices. The global cellular connectivity market is a patchwork of MNOs and available protocols. If you manufacture a device you’d like to sell in multiple national markets, you need the ability to integrate with the carriers that are available regionally. An eSIM allows you to hard-wire this flexible MNO coverage into your devices.
  • Simplified inventory management with a single SKU for all markets. Using removable SIM cards for multiple MNO relationships requires manufacturers to maintain complex and costly stock-keeping units (SKUs)—identification codes for product lines—to organize inventory and logistics. A SIM card for one MNO requires one SKU; the same device headed for a different market, with different MNO coverage, requires another. With a multi-carrier eSIM, you can use the same module for all your devices, achieving the clarity of a single SKU.
  • More efficient and cost-effective product launches. You don’t have to set up MNO relationships before shipping with an eSIM. You can use a bootstrap profile for limited connectivity to any network, launching a minimally viable product to test the market. Once you move into the expansion phase of launch, you can provision the eSIM for local MNO connectivity, scaling seamlessly.

eSIM Advantages for End Users

  • Switching owners and user profiles “over the air,” without having to physically exchange SIM cards. In an industrial IoT environment, different users may operate the same IoT machinery. With an eSIM, you can switch user profiles without physically changing, tracking, and storing physical SIM cards.
  • Smaller, more durable devices. Today’s eSIMs use a small form factor called MFF2, and they don’t require external access. That makes them fit into smaller and smaller spaces—allowing devices to be smaller. These eSIMs are also vacuum-sealed, so they can operate in wet and corrosive environments. They’re also more shock-resistant than removable SIMs.
  • Avoiding roaming charges in mobile assets. Because they can switch seamlessly from one MNO to another, eSIMs allow mobile IoT solutions (on trucks, say, or farming equipment) to avoid the high roaming charges associated with traditional carrier contracts.

These are only a few of the benefits of cellular eSIMs—but they’re enough to explain all the headlines this technology is earning.

What are Some Good Use Cases for Cellular eSIM Implementation?

Today, eSIMs remain in the early stages of widespread use. While they may become the dominant technology across applications, their advantages have led to increased adoption in a few distinct use cases so far: 

  • Devices with long lifespans, like security systems. A long-lived IoT device may encounter lots of changes in the MNO environment. One carrier may leave, and another may take over. Meanwhile, devices like IoT security cameras are often placed in tough-to-reach areas. With eSIMs, operators save the expense of switching out physical modules every time they need to change MNOs.
  • Vehicle-based IoT devices, such as telematics. The trucking industry relies on IoT for valuable telematics and freight-tracking systems—but these trucks also travel through multiple MNO coverage areas every day. The eSIM allows them to seamlessly switch to a new carrier rather than face roaming charges as they travel.
  • Stationary monitoring devices in harsh environments. IoT powers a variety of monitoring technologies: water, air quality, soil, and even mining equipment, just to name a few. Remember that eSIMs are vacuum-sealed; they’re ideal for use in water-proof and weather-resistant equipment. And because these monitoring tools are often extremely remote, being able to switch MNOs and user profiles from afar is particularly valuable.

Again, this list is meant to be illustrative, not comprehensive.       

Will MNOs Support eSIM Everywhere? 

Roaming agreements are a valuable source of income for MNOs, and the ability to switch networks threatens that status quo. We’ve even suggested that carriers will remain reluctant to invest in architecture for a technology that can limit customer loyalty. Still, there’s evidence that more MNOs will support eSIM and other multi-carrier solutions—and that the shift is already underway. After all, connecting to cellular eSIM devices is also a strong revenue stream. 

Meanwhile, powerful manufacturers like Apple and Tesla have already moved to eSIMs, placing pressure on MNOs to support them or lose market share to a competitor who will. Finally, MNO resistance to sharing customers is primarily a U.S. phenomenon; the European Union, for instance, tightly regulates the rates carriers can charge customers and each other for roaming, reducing the drive for restrictive contracts.        

Are eSIMs as Secure as Removable SIM Cards? 

The short answer is: yes. According to GSMA, which defines protocols for global IoT devices, eSIM “provides an equivalent level of security as the removable SIM card.” To comply with GSMA standards, M2M eSIMs must reach an assurance level of EAL4+ according to GSMA’s Common Criteria Protection Profile. It must also ensure production environment and process security according to the GSMA Security Accreditation Scheme, and show functional compliance based on GSMA testing protocols. Consumer eSIMs must meet similarly rigid standards. In short, GSMA has taken steps to ensure that eSIMs remain as secure as their predecessors. 
Of course, every cellular eSIM implementation is unique, and no single FAQ can tell you everything you need to know to ensure successful adoption. To learn more, check out our coverage of eSIM localization—and get answers to all of your eSIM questions from the experts themselves at this free webinar with Aeris.

IoT For All
IoT For All
IoT For All is creating resources to enable companies of all sizes to leverage IoT. From technical deep-dives, to IoT ecosystem overviews, to evergreen resources, IoT For All is the best place to keep up with what's going on in IoT.
IoT For All is creating resources to enable companies of all sizes to leverage IoT. From technical deep-dives, to IoT ecosystem overviews, to evergreen resources, IoT For All is the best place to keep up with what's going on in IoT.