The SIM card turned 30 in 2021.
For three decades it sat in virtually every mobile device on the planet – a small piece of plastic carrying a network identity, a security credential, and the commercial relationship between a user and a mobile operator. It was the physical token of connectivity. You couldn’t use the network without it.
That’s ending.
Not quickly. Not cleanly. But the trajectory is clear and the hardware is already shipping. The integrated SIM – iSIM – removes the last physical boundary between the device and the network. And when you combine it with Non-Terrestrial Networks, the result is something the cellular industry has never had before: genuinely global, zero-touch connectivity with no discrete SIM component, no coverage gap, and no physical intervention required at any point in the device lifecycle.
This is the final post in the euicc.co.uk series on eUICC, eSIM, and what comes next. The previous two posts covered the eUICC architecture and the SGP.32 transition. This one covers where it all ends up.
The Evolution in Three Steps
It helps to understand what each generation actually changed – not just the form factor, but the underlying architecture.
Step 1: The traditional SIM
A discrete, removable component. The security element, the network profile, and the physical card are one thing. To change network, you change the card. The operator controls the relationship through a physical token. Simple, effective, and completely inflexible.
Step 2: eUICC
The security element becomes a dedicated chip – removable or soldered to the PCB as MFF2 or SON-8. It supports multiple profiles stored and managed remotely via the SM-DP+ platform. You no longer need to change the hardware to change the network. SGP.32 took this to its logical conclusion for IoT: fully automated, zero-touch remote provisioning at scale.
But eUICC is still a discrete component. It still has to be sourced, certified, placed on a PCB, and managed as a separate element in the device bill of materials. The chip is smaller. The flexibility is real. The component is still there.
Step 3: iSIM
The security element is integrated directly into the application processor or system-on-chip. There is no separate SIM component. The network identity, the security credentials, and the profile management capability all run inside the same silicon that runs the rest of the device.
The SIM as a component disappears entirely.
What iSIM Actually Is
iSIM is not a new provisioning specification. It runs on the same GSMA SGP.22 and SGP.32 standards as eUICC. The SM-DP+ platform, the remote profile management, the multi-network capability – all identical. What changes is where the secure element lives.
In a traditional eUICC implementation, the secure element is dedicated silicon – separate chip, separate supply chain, separate certification, communicating with the application processor over an ISO 7816 or SPI interface.
In an iSIM implementation, the secure element is a Trusted Execution Environment (TEE) within the main SoC. ARM’s TrustZone architecture is the most widely deployed implementation. It creates a hardware-enforced boundary within the processor – isolating the secure world, where the SIM credentials and cryptographic operations run, from the normal world, where the application code runs. The two environments share the same physical silicon but cannot access each other’s memory or operations.
From the SM-DP+ platform’s perspective, an iSIM device looks identical to an eUICC device. The provisioning model doesn’t change. The management interface doesn’t change. What changes is everything on the device side:
- No separate SIM component in the bill of materials
- No ISO 7816 interface between SIM and processor
- No SIM certification track separate from the SoC
- No SIM tray, no slot, no holder – nothing to corrode, nothing to fail mechanically
- Smaller physical footprint
- Lower power consumption
- Lower unit cost at volume
For IoT device designers, these are not marginal improvements. At scale they are significant.
The Hardware Already Shipping
This is not a specification exercise. The silicon exists and is deployed in production.
Nordic Semiconductor nRF9160
The nRF9160 is a System-in-Package LTE-M and NB-IoT module with the SIM integrated directly. Widely deployed in asset tracking, industrial sensors, and wearables. The integrated SIM runs SGP.02, which limits remote provisioning flexibility compared to SGP.32, but the hardware architecture is iSIM. Thousands of production deployments are already running it. Nordic’s follow-on nRF9161 and nRF9151 maintain the integrated SIM with updated modem capability.
Qualcomm Snapdragon X series
The X55 and X65 modems include iSIM capability, designed primarily for consumer devices – laptops, tablets, high-end smartphones. The Snapdragon X Elite, targeting PC platforms, includes iSIM as standard. This is iSIM at consumer volume – which means the certification infrastructure, the tooling, and the SM-DP+ platform integrations are maturing fast. What gets certified at consumer scale filters down to IoT.
MediaTek
MediaTek’s IoT-focused SoC roadmap integrates SIM functionality directly, targeting mid-range and high-volume IoT – smart home, industrial, automotive adjacent. MediaTek’s volume position in emerging market devices means iSIM adoption in those product categories will be fast once the design wins land.
STMicroelectronics and NXP
Both are offering iSIM-capable secure element IP for integration into partner SoCs rather than as standalone chips. The model is IP licensing – the iSIM secure element becomes a block in a larger SoC design. This is how the technology permeates the broader chipset ecosystem over time.
The certified SGP.32-capable iSIM device ecosystem is still maturing. But the direction is established, the volume will follow, and the design wins happening now in consumer electronics will accelerate industrial adoption within a two to three year lag.
What iSIM Means for IoT Deployment
The operational implications go well beyond the component count.
Miniaturisation without compromise
MFF2 eUICC chips are small but still impose a minimum footprint on PCB layout. For the smallest IoT devices – environmental sensors, medical wearables, agricultural monitoring nodes, logistics tags – that footprint matters. iSIM removes it. A connected device can be designed to the constraints of the application, not the constraints of the SIM component.
Manufacturing simplification
Every discrete component is a point of complexity – sourcing, placement, testing, potential failure mode. Removing the SIM from the component list simplifies production, reduces the supplier count, and eliminates one class of manufacturing defect. At tens of thousands of units, that’s meaningful. At millions, it’s significant.
Improved security posture
A discrete eUICC chip, however tamper-resistant, is a physical component that can be identified, probed, and in some cases extracted. An iSIM integrated into the main SoC is substantially harder to attack physically – you would need to attack the entire processor package. For critical infrastructure, medical devices, and defence-adjacent applications, this is not a trivial distinction.
Supply chain consolidation
The SIM supply chain has its own complexity: SIM OS vendors, form factor sourcing, separate certification tracks, separate procurement relationships. iSIM consolidates this into the SoC. One supplier relationship, one certification process, one component. For a procurement team managing a large device programme, that simplification has real value.
The risk that remains
iSIM makes physical intervention impossible. There is no component to replace. If the provisioning relationship breaks in a way that cannot be recovered over the air – corrupted profile, platform outage during a critical switch, edge case in the provisioning workflow – the device has no cellular connectivity and no physical recovery path.
This is the same fundamental risk as MFF2 eUICC, but more absolute. With MFF2, de-soldering is theoretically possible. With iSIM, it isn’t.
The practical implication: iSIM deployments demand robust SM-DP+ platform reliability, properly tested failure recovery procedures, and clear contractual SLAs on the provisioning platform before you commit production hardware to the model. The platform risk doesn’t disappear. It becomes the only risk.
Non-Terrestrial Networks: Closing the Coverage Gap
iSIM solves the component problem. Non-Terrestrial Networks solve the coverage problem.
Cellular IoT has always had a hard ceiling. No matter how capable the device, no matter how well-designed the provisioning architecture – outside terrestrial coverage, the device is offline. For the applications where IoT has the most transformative potential – remote infrastructure monitoring, maritime logistics, precision agriculture, environmental sensing at continental scale – that ceiling has been the fundamental constraint.
3GPP Release 17, published in 2022, changed the architecture.
Release 17 formally defined NTN support for NB-IoT and LTE-M. In technical terms: a standard cellular modem, with no hardware modification, can communicate with a Low Earth Orbit satellite using the same protocols it uses with a terrestrial base station. The satellite acts as a relay – a bent-pipe node that forwards the cellular signal between the device and a ground station, or in more capable implementations, a regenerative node that processes the cellular protocol in orbit.
The same SIM. The same modem. The same provisioning architecture. Terrestrial or satellite coverage, selected by the network based on availability. Seamless handover between the two.
This is not a theoretical capability. It is shipping.
The Players Making NTN Real
SpaceX Starlink Direct to Cell
Starlink’s D2C programme uses LEO satellites with eNodeB capability – essentially a cellular base station in orbit. The T-Mobile partnership demonstrated text messaging to unmodified LTE handsets in 2023, with voice and data capability following. The coverage proposition is simple: anywhere with sky visibility has cellular coverage. No exceptions, no exclusions.
The commercial model is still developing. The technical proof of concept is established at scale with a constellation that is already the largest in orbit.
AST SpaceMobile
AST SpaceMobile’s BlueWalker and BlueBird constellation is specifically designed for broadband direct-to-device cellular. Their approach uses very large phased array antennas in orbit to achieve the link budget required for standard handset connectivity without device modification. Commercial service agreements with AT&T, Verizon, Vodafone, and Rakuten position AST as the NTN layer underneath major operators’ existing terrestrial networks.
For IoT specifically, the AST model means existing network relationships extend into genuinely global coverage without a separate satellite data contract.
Lynk Global
Lynk has taken a different route – focusing on 2G and narrowband messaging first, then expanding capability. Their model is specifically aimed at extending existing MNO coverage into remote areas. They operate as a wholesale NTN provider for operators rather than a direct consumer service. For IoT deployments in regions where terrestrial coverage is thin, Lynk’s operator partnership model is relevant.
Skylo
Skylo operates as an NTN service provider using geostationary satellites rather than LEO, targeting specifically NB-IoT for low-bandwidth IoT applications – the asset tracking, remote monitoring, and agricultural sensor use cases where latency matters less than coverage and cost. Skylo’s approach integrates directly with existing NB-IoT device designs. Their partnership with T-Mobile US and others positions them as an NTN extension layer for existing IoT deployments, not a replacement.
The eSIM and iSIM layer is what makes seamless terrestrial-to-NTN handover possible. Without remote profile management, switching between a terrestrial MNO profile and a satellite profile requires physical SIM intervention. With SGP.32 remote provisioning on an iSIM device, the switch is orchestrated by the platform based on coverage availability – invisible to the device, invisible to the end user.
What the Combined Picture Looks Like
Pull iSIM and NTN together and the picture that emerges is this:
A connected device leaves the factory. It has no discrete SIM component. Its network identity is provisioned at manufacturing via the SM-DP+ platform. It ships to any location on the planet. On arrival, it connects – to a terrestrial network if one is available, to a LEO satellite if not. It receives the optimal network profile for its location automatically. Over its operational lifetime – ten, fifteen, twenty years – it can be reprovisioned remotely as networks change, operators come and go, and coverage landscapes evolve.
No SIM swap. No engineer visit. No coverage gap. No physical intervention of any kind after the device leaves the factory.
That is not a future state. It is the direction every component of the technology stack is pointing toward simultaneously. The specification work is done. The hardware is shipping. The commercial deployments are live.
The timeline to this being the default for new IoT hardware programmes is not decades. Based on the chipset roadmaps, the 3GPP standardisation trajectory, and the NTN constellation deployment schedules, meaningful production deployments running this full stack are a three to five year story from now.
What It Means for the Industry
The previous post in this series covered what SGP.32 does to the distribution channel. iSIM plus NTN completes that argument.
If zero-touch provisioning via SGP.32 removed the SIM logistics layer, iSIM removes the SIM component layer. The physical object that anchored the commercial relationship between operator, reseller, and end customer is gone. What replaces it is a platform relationship – access to SM-DP+ infrastructure, multi-network agreements, and the management layer that sits above the device.
The businesses that survive this transition are the ones providing value in that platform layer. The connectivity itself – the raw data transport – is already close to a commodity and moves further in that direction as NTN removes the coverage premium that remote deployments currently attract.
The value is in:
- Managing device estates across their full operational lifecycle
- Integrating connectivity into wider IoT platform propositions
- Providing the professional services layer that enterprise customers need to navigate the complexity of the transition
- Owning or accessing SM-DP+ infrastructure with genuine multi-network depth
The SIM reseller model built on physical distribution is not just disrupted. It is structurally eliminated by the hardware direction.
The question for every business currently in the cellular IoT connectivity chain is not whether this happens. It’s whether they’re building toward the platform layer before the transition forces the decision.
The Longer View
The cellular industry spent thirty years optimising around the SIM as a fixed point – the physical token that anchored identity, security, and commercial relationships. Every network architecture, every commercial model, every distribution chain was built with that token at its centre.
iSIM removes the token. NTN removes the geographic constraint. SGP.32 removed the need for human intervention in provisioning.
What’s left is a cellular connectivity layer that is, for the first time, genuinely software-defined from end to end. Network identity managed as data. Coverage as a software-orchestrated selection between available bearers. Device lifecycle managed remotely across a platform.
That’s a different industry to the one that grew up around the SIM card. The companies that will define it are not necessarily the ones that defined the last thirty years.
Credits and Sources
3GPP – Release 17 NTN specification details sourced from 3GPP published technical reports. Full documentation at 3gpp.org.
GSMA – iSIM specification context and SGP.22/SGP.32 provisioning standard references sourced from GSMA published documentation at gsma.com.
Nordic Semiconductor – nRF9160, nRF9161, and nRF9151 product details sourced from Nordic Semiconductor published product documentation.
Qualcomm – Snapdragon X series iSIM capability referenced from Qualcomm published product specifications.
SpaceX / Starlink – Direct to Cell programme and T-Mobile partnership details based on publicly announced commercial agreements and Starlink published service information.
AST SpaceMobile – Constellation and operator partnership details based on publicly reported commercial agreements and AST SpaceMobile investor communications.
Lynk Global and Skylo – Service details referenced from publicly available company and partner announcements.
This is the third post in the euicc.co.uk series on eUICC, eSIM, and the future of cellular IoT connectivity. Previous posts: eUICC Explained and What Comes After SGP.32?