eSIMs: What They Are, What They’re Not, and When They’re Right for You

Ralph Heredia
Mar 2, 2021 8:30:00 AM

The physical little chip consumers and companies have inserted into phones and other devices for years may soon be a thing of the past thanks to the rise of eSIMs. The eSIM is already changing the way we connect our devices to wireless carrier networks and eSIM interest is growing rapidly.

It has been predicted that by 2025 there will be 2 billion eSIM enabled devices globally.

The SIM (Subscriber Identity Module) card has undergone rapid transformation in the last three decades. It appeared in its initial form in 1991 when it was about the size of a credit card. Then, by 1996 the Mini-SIM was on the market, in 2003 this was changed to the Micro-SIM followed by the Nano-SIM in 2012. The future of the SIM card will be something that we won’t manually place into devices - the eSIM. While a traditional SIM card (or socket SIM as it is often known) can be physically removed from the device and changed by the end user, eSIMs are different.

What is an eSIM?

The word eSIM itself can actually be interpreted two different ways with different meanings. The first definition, is that of an embedded SIM (the “e” in eSIM) that is surface mounted on the board. This SIM comes in the form of an integrated circuit (IC) that is intrinsically part of the IoT device. No longer a separate, plug-in card, it still works the same as a traditional socket SIM card. It is part of the device’s main electronics board and serves the same purpose of identifying the device to a network carrier but is installed at manufacturing time along with the other IC’s. Another name for this type of SIM is an MFFC or UICC. This SIM then replaces the need for a socket and a plug-in card.

The alternate definition is what is known as an electronic SIM that is software programmable at activation time to determine which carrier is going to be the default carrier of use. While technically this SIM does not have to be surface mounted and this functionality could be supported in a socket SIM, in practice it is typically used in the same form factor of an MFFC/UICC, but is referred to as an eUICC.

Mobile phones were the first to widely adopt eSIMs. Now, multiple other electronics devices such as smartwatches, smart meters, and other IoT devices can also have eSIMs built-in.

eSIMs (both the embedded and electronically programmable kinds) have been used in mobile phones so that a customer can pick the carrier of choice, at the time they are purchasing the mobile phone.

These first eSIMs also known as “Consumer eSIMs” were introduced with the intended purpose of allowing a consumer to purchase a phone or other consumer device, generally at a retail location, and pick the carrier of choice. In order to support retailers in their effort to simplify the purchase process for end-users, specialized software infrastructure and agreements were put in place to support this capability, and for the time being this access has been limited to specific retailers and device manufacturers that can guarantee significant device volumes upfront.

Some mobile phones have both an eSIM as well as a socket to support a plug-in SIM. There are valid reasons to have a dual SIM (eSIM and socket SIM) approach in some IoT devices, such as a dual SIM router. Obviously, this assumes that the IoT device in question can support the size requirements (there are many that cannot like a compact wearable), and the software capabilities to switch between the two SIMs in the device.

IoT devices, with the promise and prospect of growth into the billions (or trillions) of devices, are treated differently than traditional “Consumer” devices - although all interested parties see value in offering IoT eSIMs with the same capabilities as Consumer eSIMs.

Work is underway from many of the major stakeholders in the industry to address the scale, security and business challenges that come with programmable eSIMs in an IoT environment.

As an example, in a previous blog post, we discussed the differences between platforms that support Consumer SIMs and connectivity management platforms that were specifically designed to support IoT devices.

In the following section, we will primarily focus on the embedded SIM and will denote items that are specific to the other, electronically programmable SIM as necessary and where appropriate.

What Are the Advantages of eSIM?

The embedded SIM offers multiple advantages for OEMs and end customers of IoT devices. The advantages of an eSIM include:

  • Lower costs - the cost of a surface mount integrated circuit is lower than the cost of supporting a socket SIM and installing the SIM at manufacturing time
  • Improved reliability – because the eSIM is surface mounted on the electronics board it is much more reliable in vibration intensive applications (like a car, scooter or other device).
  • Stronger security - with no physical card to remove from a device, an eSIM makes it no longer possible to remove the SIM from a device and insert it into another, unauthorized device.
  • Smaller device size - without the need to support the insertion of a physical card, devices will become more streamlined and user friendly with more space for other components like a bigger battery

Even if the embedded SIM is not necessarily an electronically programmable SIM, a single eSIM can provide worldwide carrier connectivity through the roaming agreements offered by carriers such as those offered by Zipit.

What Are the Disadvantages of eSIMs?

There are of course, as with everything, a few disadvantages. These include but are not limited to:

  • Not easily disposable - the SIM is built into the device itself, unlike a socket SIM which can simply be removed from the device.
  • Lower Cost but assumes higher volumes – eSIMs (UICC) are designed for higher volume production and therefore have minimum purchase requirements numbering in the thousands. They are also only available in reels intended for the manufacturing line.
  • Inability to switch devices quickly - as the eSIM cannot be removed from the device, it makes it harder to switch between devices such as if transferring ownership of the device to a new owner. For example, you could have a wireless router that is certified for use on two different carrier networks, but the ICCID may be limited to one of them, preventing you from switching.

A Single SIM That Roams Globally

Many OEMs want to offer their devices in many different markets, and so there is a basic desire for SIMs that can work reliably around the world.

There are several ways to address the global SIM requirement, even by using the embedded SIM (eSIM) form factor that is not electronically reprogrammable.

In fact, whether it is an embedded SIM or even a traditional socket SIM, the answer is generally the same at the current time.

The current method is to use a Global IoT SIM from a top-tier carrier that can – through the use of their extensive roaming agreements, provide coverage across a global footprint of carrier partners.

Zipit, for example, continues to work with these global partners to provide increasing coverage across all markets for the various IoT technologies that are being deployed worldwide. There is some nuance to this however, because while network operators currently have global roaming agreements in effect, many of those are only applicable to LTE (Cat 1 through Cat 4 and beyond) applications. This is in contrast to newer network technologies like NB-IoT and M1 networks that are now being deployed to specifically support IoT applications with lower data volume expectations and these roaming agreements are just now being put in place.

Networks like NB-IoT have been promoted as the ideal alternative to legacy 2G networks, that are still very much in use in certain markets, especially internationally. These legacy networks will eventually need to make the switch as older technologies come to their end-of-life.

As with all network migrations that came before, this transition will take time to roll out, and in the meantime there are still territories and geographies around the world that do not have access to the latest and greatest networks – yet. It can be difficult for OEMs to navigate these challenges in the short to mid-term, so Zipit has deployed agreements with our carrier partners to help support OEMs now and into the future as they make the transitions required to future-proof their solutions.

Striking a Balance Until eSIMs Are Ubiquitous

First, the question OEMs need to answer is – what are you trying to accomplish?

Depending on your IoT use case and your goals, a Global IoT SIM with robust roaming agreements, options like dual SIMs, or unique SKUs can solve the challenges you are likely to face around coverage, reliability and speed of deployment.

Note that even if your goal in having a single SIM is to have a single SKU, the technology inside your device may impact your ability to deliver on this goal – think of antennas, modules, frequencies/carrier bands, and unique module firmware.

Zipit has already helped OEM customers navigate each of the scenarios above, according to their technology and business needs. We continue to work alongside the carriers to try to bring eSIM capabilities to more companies and IoT use cases going forward.

How IoT Is Driving the Evolution of Programmable eSIMs (eUICC)

As we have established, there is a lot that goes into supporting IoT from a SIM or eSIM perspective. From the specific network technology available in a given market, to which carriers offer coverage in those markets, to determining the cost impact of that support.

Especially as IoT bifurcates into specific standards like NB-IoT, Cat-M1, LTE and the upcoming 5G deployments with their own carrier-specific implementations.

eSIMs will eventually be a viable option for IoT applications but there is still much work to do until they are viable for the majority of use cases and users. IoT devices are different from the devices that came before like mobile phones. There’s additional complexity from the numerous standards, hardware and software that are being developed and offered by vendors throughout the IoT ecosystem.

However, just as the adoption of eSIMs in the mobile market were primarily driven by the desire to simplify inventory needs and the subscription activation process, so to do those drivers apply to the IoT market.

Zipit’s position as the subscription enablement platform for IoT devices, and our relationships with the world’s leading cellular carriers, gives us a unique perspective into the process of bringing the programmable eSIM to the diverse world of IoT and how to solve the transactional challenges ahead in order to make that a reality.

Determining if eSIMs Are a Good Fit for Your IoT Product

When deciding whether your IoT device should have an eSIM, things to research and consider are:

  • The type of connectivity required for the device
  • The difference between IoT SIMs and Consumer SIMs, and how they are managed
  • The optimal billing model for the devices you are using
  • How you plan to handle product returns and subscription migrations
  • Is your goal to create a single SKU through an embedded SIM or is your interest purely in mitigating potential coverage issues?
  • What is your ultimate market goal from a geographical standpoint – Is most of your market opportunity in North America, with some potential deployments or roaming in Europe or Latin America?

To learn more about how your IoT devices can benefit from multi-carrier coverage while leveraging a single pane of glass where you can view your business results, get in touch with us today. Our experts can share their advice and offer demos of how Zipit's platform can aid your business.

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