Is eSIM the Accelerant IoT Has Been Waiting For?

By Greg Coogan

Business Development Manager


June 11, 2021


Is eSIM the Accelerant IoT Has Been Waiting For?

Connectivity is a simple word for something that is often anything but simple. It’s the key to the thousands of concepts for wearables, automobiles and logistics solutions in the expanding universe of the ‘Internet of Things’ (IoT). For systems builders, the choice of connectivity technology will have a significant impact on availability, reliability, user experience and, ultimately, the success of the solution. Low-Power Wide-Area Network (LPWAN) technologies offer a broad range of solutions, from short-range in-building to nationwide solutions although with limitations. However, it is cellular wireless, under the umbrella of the 3rd Generation Partnership Project (3GPP), that offers true worldwide connectivity.

Narrowband IoT (NB-IoT) was specified in 3GPP Release 13, while LTE-M was defined in Release 12, providing IoT solution developers with low-power worldwide connectivity as Mobile Network Operators (MNOs) rolled-out support. 5G also addresses IoT requirements, adding massive connectivity as one of its three core focus areas alongside high-bandwidth and ultra-reliable low-latency communication. Taken together, the importance of cellular for the IoT connectivity is clear, and it’s expected that billions of cellular connected IoT devices will be deployed in the next several years. 

The Fiddly SIM

Inserting a Subscriber Identity Module (SIM) into a gleaming new handset has, for decades, been a rite of passage to connectivity. However, since its introduction in 1991, it has struggled to keep pace with shrinking handset sizes and, with the 4FF format, seems to have exhausted the available superlatives. While the SIM is an occasional fiddly challenge for consumers, it is a multi-pronged problem for IoT product manufacturers. If users can change the SIM, it is more challenging to protect against dust and moisture ingress in products designed for use outside. In addition, IoT devices with a cellular contract need multiple stock-keeping unit (SKU) numbers, even if the only difference between products is the MNO’s SIM.

Further issues arise that impact both supplier and consumer. Let’s look at one example, trail cameras, which have gained popularity to monitor wildlife and farm herds, with many offering pre-packaged cellular connectivity. Potential purchasers know which MNO provider delivers the best coverage in the region where the camera is to be used. If the camera with the desired MNO is not available, they will opt for an alternative, resulting in a lost sale. Suppliers are caught in the middle, trying to manage stock and demand based on a factor over which they have no control.

Physical handling of the SIMs during manufacturing is also difficult to automate, adding to costs. Furthermore, should the camera cross borders, say from the U.S. into Mexico or Canada, it may become non-functional or incur high roaming charges, like the story of the steppe Eagle tracked by Russian scientists.

The eSIM

Clearly, a new approach to the SIM challenge is needed. The removable plastic SIM hails from the days when cellular meant speech, and speech meant human communication. Cellular technology has advanced significantly since, making it possible to ‘reprogram’ the SIM over the cellular network to achieve the same result as replacing the SIM. The Embedded-SIM, or eSIM, is a combination of silicon technology coupled with standards supported by the cellular networks of MNOs.

The Global System for Mobile Communications Association (GSMA) has developed a specification named Remote SIM Provisioning (RSP) that defines how MNOs can update the subscription data stored in an eSIM using an over-the-air (OTA) process. For consumers, this means that changing cellular contract can be undertaken by scanning a QR code rather than physically exchanging the plastic SIM. For IoT device suppliers, it makes it possible to disseminate new subscription data to all connected devices at the push of a button.

On the device end, the old SIM and connector are replaced by an eSIM solution that is soldered to the IoT device’s board during manufacture. Because security is embedded in the device, there is no need for a specifically secured programming facility or data servers. The Motorola razr handset is one of the first to ditch plastic SIMs, while wearables such a smartwatches have adopted them out of necessity. While the largest M2M/IOT user of eSIM products today is the automotive industry, which uses them to support their various connected services (Figure 1), much of the growth in eSIMs will come from non-automotive applications.

Figure 1. Automotive is responsible for the lion’s share of eSIM-enabled nodes, though other IoT segments will grow in the next few years. (Source: ABI Research, eSIM in the Consumer and M2M Markets Q1-2020)

Deceptively Simple, Highly Secure

Despite their diminutive size and simple low pin-count interface, eSIMs are a highly-secure computing platform. Devices such as the OPTIGA™ Connect IoT OC2321 from Infineon, are based on security controllers; in this case a 32-bit ARM® SecurCore® SC300™. Operating at 44 MHz and equipped with 1 MB of flash and 32 Kbyte of SRAM, it is fully compliant to GSMA SGP.02 Remote Provisioning Architecture and have space for up to 10 MNO profiles. Available in a tiny VQFN-8-4 package measuring just 5 × 6 × 0.9 mm, it requires less than 30% of the board area of a plastic nano-SIM (Figure 2). With its -40 °C to +105 °C industrial operating range, it is also well suited to IoT applications in extreme operating environments, including remote maintenance access in wind turbines, asset tracking and vehicle charging points (Figure 3).

Figure 2: The OPTIGA Connect IoT saves more than 30% board area over a classic plastic SIM and cage approach.

Figure 3: Diminutive size and an industrial temperature operational range makes eSIMs ideal for worldwide deployment of IoT applications.

This turnkey eSIM approach means that IoT manufacturers can offer their products under a single SKU globally while simplifying the management of subscriptions and costs through a single provider. Furthermore, users benefit from their dedicated infrastructure hosting and uptime, coupled with state-of-the-art cybersecurity, allowing manufacturers to focus on the IoT offering's features and product differentiation. Using OTA updates, IoT deployments can be provided with additional roaming partners to take advantage of lower data costs.

One of the challenges for IoT device manufacturers is finding MNOs that provide the optimal balance of coverage, cost and service across the deployment regions. A device using one MNO profile may incur high data costs in several countries, although the IoT manufacturer has access to local MNOs offering lower charges. The OC2321 resolves this thanks to a pre-loaded bootstrap profile that works worldwide in conjunction with the Tata Communication MOVE™ global IoT solution (Figure 4). Specifically targeting IoT and M2M connectivity, Tata has agreements with more than 900 MNOs across 230+ territories. This provides significant negotiation leverage on contracts, allowing them to provide highly competitive connectivity packages that would be beyond the grasp of an individual business.

Figure 4. Bootstrap access to the Tata Communication MOVE global IoT solution greatly simplifies cellular connectivity.

While an eSIM may be slightly more expensive than a plastic SIM, systems cost savings more than make up the difference. The SIM tray and handling costs for SIM installation fall away entirely. Lost sales due to lack of product availability with a preferred MNO become a thing of the past. Simplification in inventory also adds to cost savings. Furthermore, IoT device suppliers are able to provide users with more customizable data packages and connectivity options, allowing them to differentiate over competitors and without the constraints of working with a single MNO.

eSIM: Connectivity Made Simple

The plastic SIM is a technology on the wane from a time when cellular connectivity meant human voice connectivity. With billions of IoT nodes being added each year, it is time to switch from the fiddly plastic SIM to the eSIM, a solution that meets the connectivity and configuration expectations of the 21st century. With its significant space savings and simple handling during manufacture, the eSIM solves a diverse range of challenges for IoT product manufacturers. 


  1. Global M2M/IoT Communication Market: