eSim (Embedded Sim) & iSim (Integrated Sim) - IoT software innovations & revolutions in the telecom industry

December 5, 2022
eSim (Embedded Sim) & iSim (Integrated Sim) - IoT software innovations & revolutions in the telecom industry


What if we told you that physical sims might be replaced entirely in the coming days? It is still widely used, with technology working to reduce its size and boost its efficiency.

During this process, the eSIM was configured. An embedded sim or eSIM is also used with select phones and devices. To use an eSIM, selecting a carrier that provides an eSIM facility is necessary.

But with the advent of IoT in the telecom industry, the eSIM only got to take to the throne after its predecessor, iSIM, was invented.

If eSIMS were compact and secure, iSIMs would go the extra mile and be integrated directly into the processor. So how do eSIMs and iSIMS differ, and which of these is set to revolutionize the industry?

This blog explains the two and discusses which technology may have the upper hand.

Why is the physical SIM being replaced?

A physical SIM card (Subscriber Identity Module) is the standard card that fits the SIM slot on the phone. It is portable and can be easily switched between devices. Physical SIMs are most in usage in the consumer mobile phone market.

The standard size of physical SIM cards used to be 12x15mm, but their smaller counterparts, such as microSIM and nanoSIM, are more in use.

But the simplicity of the physical SIM is its drawback in some cases. As it is easy to remove and tamper with, it cannot be used in IoT devices. Moreover, the IoT ecosystem may contain several devices and be deployed on a large scale. Monitoring each IoT device for such risks may not be possible.

Switching between carriers or network providers is easy and convenient with the physical SIM. The physical SIM of one provider would have to be removed and replaced with the other provider. But this is not feasible for IoT technology due to the large number of devices involved.

What is an eSIM?

An eSIM is an embedded sim that runs on the same networks as physical SIM cards. However, an embedded sim card fits onto the phone's motherboard and doesn't require the physical slots provided for SIM cards.

So, how is eSIM authentication done? The setup consists of two steps. First, one can buy the plan from the eSIM provider and scan a QR code to activate and use it.

However, not all phones or devices are compatible with an eSIM. Therefore, one may need to check the technical specifications of a device beforehand and verify with the carrier whether the eSIM service is available.

What are the benefits of an eSIM?

Did you know that the automotive industry has widely adopted eSIMs? Most connected cars use eSIM due to the security and connectivity needs provided.

The benefits of an embedded sim include

  • The compatibility and usage of eSIMS are lesser than that of physical sims but higher than that of iSIMs.

  • They allow users to have dual SIMs without needing dual sim ports.

  • It can also allow domestic and international number plans for customers who frequently travel and want to save on data rates.

  • Set up is as easy as scanning the QR code with the device post-purchase of a plan.

  • It is secure as it is physically hard to retrieve from the device in the case of theft.

What is an iSIM?

An iSIM or integrated sim is the next step post the rule of eSIM. A physical SIM needs dedicated sim slots, and an eSIM requires a dedicated chip. Still, iSIMs are directly integrated into a device's central processor and are embedded within the device's system-on-chip (SoC).

iSIM is smaller than eSIMs and spans a size of less than a millimetre. However, it is where the advantage lies; iSIM can be used in devices with space constraints, such as intelligent devices, watches, and battery-operated IoT devices.

The iSIM technology is the solution that solves the issue of constant connectivity in IoT devices. Currently, IoT technology depends on Wifi connections to receive and transmit information.

With iSIMs, this is set to change. IoT-enabled devices can avail data with iSIMs. It leads to uninterrupted connectivity, even in the absence of Wifi.

What are the benefits of an iSIM?

In this case, the switch from physical to digital is yet to be seen. iSIM is a concept that is still in its infancy, being rolled out gradually and is yet to be seen in modern smartwatches and smartphones. Some of the benefits of the technology, if implemented, include

  • It could remove the need for a physical SIM slot

  • Manufacturers can use the extra space to add additional sensors or boost battery capacity.

  • Since it is integrated embedded within the chip, phones or IoT devices can be slimmer and more portable.

  • It is cost-effective due to fewer components and simplified designs

  • Best suited for an IoT device ecosystem

How can eSIMs and iSIMs improve the security of devices?

Compared to physical SIMs, embedded SIMs and integrated SIMs are less prone to user error, are less accessible within the device, and offer added security. The primary purpose of eSIMs and iSIMs is to provide the additional layer of protection that physical SIMs fail to do.

eSIMs and iSIMs work on a foolproof method of user authentication. Physical SIMs can be duplicated, which compromises the identity of the user. eSIMs and iSIMS securely authenticate the user through a set of credentials stored within the device, which cannot be accessed from the outside. The same can also be used as an authentication token for IoT device removal via eSIM or iSIM. It removes the need for additional storage space for authentication and credentials.

The embedded universal integrated circuit card (eUICC) is a global system for mobile subscription management that allows devices to switch between multiple profiles or international mobile identity solutions. This way, based on the location, it is possible to change cellular subscriptions within the provider.

Beyond these, iSIMs offer an additional layer of security by being integrated into the system chip. As a result, it reduces manufacturing costs and can help boost the security of low-power IoT devices. These benefits also lead to IoT manufacturers focusing on customer-centric needs rather than designing devices based on physical SIM card measurements or based on the carrier network's requirements.

The difference between eSIM and iSIM: A comparison of features

eSIM (Embedded sim) iSIM (integrated sim)
eSIMs aren't as easily accessible as physical SIM cards, making them more secure in the case of a device theft iSIMs are integrated within the chip, reducing accessibility and boosting safety in the case of a device theft
Can be used for devices, to replace the space consumed by physical SIM slots Can be used for smaller, size constrained devices such as watches
Adaptation is on the rise, mainly in cellphones Adaptation is yet to see a rise, limited deployment of the iSIM is seen
eSIM is provided by carriers that also provide physical simsThe iSIM works on LTE-M and NB-IoT, which are low tier IoT connectivity options. Deployment of iSIM is not offered by major carriers.
Switching plans is easier and does not require physical removal and insertion of a different SIMHelpful for large-scale IoT deployments where physical removal of SIM to switch plans may not be possible
There are providers for eSIM who have high-security standards iSIM is relatively new and hasn't been certified yet with existing SIM accreditations

Conclusion: are eSIMs and iSIMs set to take over the telecom industry?

It is undoubtedly evident that the Internet of Things is set to take over the communication sector due to the advantages it hosts. With the advent of iSIMs, providing cellular or network connections to the smallest of IoT sensors for IoT devices is possible. This is feasible for a more extensive ecosystem with various devices and helps maintain connectivity.

eSIMs are just as beneficial and are already being implemented. When implemented correctly, they can streamline IoT deployments. In the future, we may see a combination of eSIMs and iSIMs being used, given their potential to improve IoT security and ease the deployment of large-scale IoT ecosystems.