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What is an eSIM?

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What is an eSIM? Top Tips for Finding the True eSIM

The market for eSIM is reaching a point of true realisation of a technology that has been discussed for several years now. The ability to break carrier dependency through proprietary SIM cards and leverage an eUICC card that can host multiple carrier profiles is expected to deliver benefits such as zero-touch provisioning, out-of-the-box connectivity, and future-proofing against network changes or turndowns.

Kaleido Intelligence has estimated that eSIM will provide connectivity to 2.4 billion devices in 2025 between consumer and IoT devices, with over 50 percent of compatible devices leveraging eSIM.

What is an eSIM when it comes to IoT and what is its value are two important questions to ask, particularly when considering this technology for your IoT connectivity solutions. As the demand grows for eSIM, competitive offerings will enter the market, and some of them might not have the same core functionalities of eSIM. It’s important to understand what is an eSIM, it’s architecture, and what historical connectivity pain points it is addressing.

What is an eSIM: History of eSIM

The SIM card has long been a removable chip that is placed in a device. The SIM, or Subscriber Identity Module, is what allows devices to connect to a mobile network. It’s the unique identifier that pairs to the specific carrier. If the end user requires a new network, it means a new SIM card.

The GSMA in 2016 specified a new approach to the traditional SIM card. The eSIM, or Embedded Universal Integrated Circuit Card (eUICC) is an embedded card where those same credentials for accessing a mobile network are now programmable.

According to the GSMA, the eSIM “provides a single, de-facto standard mechanism for the remote provisioning and management of machine-to-machine (M2M) connections, allowing the “over the air” provisioning of an initial operator subscription, and the subsequent change of subscription from one operator to another.”

Essentially, the GSMA is stating that the eSIM over-the-air provisioning allows for out-of-the-box connectivity. The process of having to physically provision SIMs and install them into the device is time-consuming and requires an added step in logistics and installation. This helps streamline provisioning, such as in bulk. For example, device OEMs can provision hundreds of devices at once prior to deployment. This over-the-air provisioning, as well as the ability to host more than one carrier network, is what allows the change of subscription without having to physically swap the SIM card.

The automotive industry was one of the first applications of the eSIM. Creating fleets of connected vehicles was a challenge. While the cars might be manufactured in one location, they will be shipped for sale globally. This created difficulties in installing SIMs, wireless modules, and downloading profiles. It can create a massive logistical hurdle and also slow down processes by having to segment car production by geographical shipment location. Instead, eSIM allows car manufacturers to use one common SIM and wireless module for the entire production of vehicles, later downloading profiles based on where the car will be shipped.

The same holds true for smartphone OEMs. Many device manufacturers have pivoted toward the use of eSIM in smartphones and smart devices to avoid logistical issues.

IoT is the next largest accelerant of eSIM adoption, for many benefits.

eSIM for IoT

What is an eSIM benefit for IoT? There are many, actually, and it helps create longer device lifecycles, more global accessibility, as well as connectivity reliability. IoT eSIMs are different than consumer eSIMs, it’s worth mentioning. In the consumer model, the end user chooses and initiates a request for the desired carrier profile, which enables pulling the profile from the carrier onto the device. IoT devices are managed differently. It’s important that enterprises have a way to remotely manage and assign the required carrier profile.

The benefits of eSIM for IoT include:

Future-proofed connectivity: IoT devices that are deployed over a long period of time are protected from the impact of evolving network technologies, sunsets, or service terminations, by eliminating technical or carrier lock-ins with a single SIM.

Eliminate SIM switching costs: Remote provisioning to different carrier profiles or network technologies enables organisations to eliminate the need to purchase new SIM cards and physically replace legacy SIMs.

Streamline logistics: With no need to physically replace legacy SIMs, organisations eliminate the process of managing costly and time-consuming truck rolls.

Maximise returns on IoT investments: By reducing costs and improving operational and logistical efficiencies, organisations are empowered to minimise total cost of ownership of connected devices and maximise returns on IoT investments.

The benefits of IoT aren’t restricted to a particular use case or vertical. Supply chain and logistics, healthcare, fleet, manufacturing, and many more key areas leverage eSIM for a future-proofed, seamless approach to connectivity.

What Is an eSIM Compared to Similar Technologies?

With the benefits of eSIM being realised across verticals, other similar technologies on the market might seem to carry the same benefits of the eSIM but are not a true eSIM. Some competitive technologies include:

Soft SIM

A soft SIM doesn’t have any hardware like a SIM or eSIM, meaning there isn’t a physical SIM card. An eSIM is embedded or removable, so there is still a physical chip. And most regular SIM cards are removable. With a soft SIM, the SIM functionality is delivered onto the device virtually or over the air.

An eSIM is ruggedised and can provide an additional step to security than a soft SIM, especially if the eSIM you choose for your deployments falls within GSMA IoT SAFE (IoT SIM Applet For Secure End-2-End Communication), the hardware secure element, or Root of Trust, within the SIM requires the provisioning and use of security credentials that are inside a secure place within the device. With a software-based SIM, this function isn’t possible.


IMSI stands for International Mobile Subscriber Identity and it’s essentially the unique key that allows a SIM to connect to its dedicated network. Multi-IMSI means that a SIM profile can host more than one network. This sounds similar to what an eSIM is, with one very significant differentiator.

Remember that a true eSIM is built with eUICC technology, which is what allows users to switch networks over the air. So, while Multi-IMSI can be pre-programmed with the ability to connect to more than one network, it’s the eUICC eSIM that provides the ability to provision remotely.

Dual SIM

Some mobile devices support the use of two SIM cards, described as dual SIM operation. When a second SIM card is installed, it allows users to switch between two separate mobile network services manually; has hardware support for keeping both connections in a “standby” state for automatic switching; or has individual transceivers for maintaining both network connections at once. There are several issues with this approach. First and foremost, device compatibility is going to be a challenge, since not all devices will support two SIM cards. And if an IoT device requires a smaller footprint, such as in a wearable, a dual SIM approach is not very plausible. Finally, automatic switching is necessary between both connections unless you choose to have two individual transceivers.

Some important questions to ask when looking for the true eSIM are:

  • Is this an eUICC eSIM?
  • What are my options for switching networks?
  • What is the carrier availability?
  • Is this the GSMA-specified eUICC eSIM?
  • Does this have GSMA-specified features?
  • What is this eSIM’s device compatibility?
  • Does this have multi-vendor compatibility?

Access a World of Connectivity with eSIM

Connectivity shouldn’t be limited to a carrier, device, or single SIM card. If you’re ready to learn more about the true eUICC, reach out to KORE. We’d love to get you started with our eSIM starter kit.

You can also check out our whitepaper, "Discovering the True eSIM: Crucial Elements to Global, Future-Proofed Connectivity”.

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Topic(s): eSIM , Connectivity , Featured , General

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