eSIM Technology

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eSIM Technology

by Faulkner Staff

Docid: 00021092

Publication Date: 2201

Report Type: TUTORIAL


Embedded Subscriber Identity Module (eSIM) technology is a way of
provisioning and managing the connectivity of mobile devices without the need to
insert a physical SIM card. Instead of a traditional SIM, this recent
technology uses an embedded Universal Integrated Circuit Card (eUICC),
a tiny, on-board component permanently attached to a device’s circuit board that
handle all the functionality usually reserved for a user- or carrier-installed SIM.
The eSIM provides a programmable and re-programmable interface through which devices
can be provisioned and assigned for use on a wireless carrier network. This
report will examine this technology, including its history, advantages, and
disadvantages when compared to traditional SIM cards, and the companies already
incorporating it into their products.

Report Contents:

Executive Summary

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Embedded Subscriber Identity Modules, or "eSIMs," are designed to replace
physical SIM cards with an embedded Universal Integrated Circuit Card (eUICC).
The eSIM is capable of accepting programming from the user and carrier to assign
the unique identifiers needed to provision a given device on a carrier
network.1 This opens a plethora of options that are not possible with devices equipped with a traditional SIM card,
such as the capability to be program and re-program the device
remotely, to handle multiple accounts across multiple carriers at a single
time, and to better handle many of the requirements of M2M (Machine to
Machine) and IoT (Internet of Things) installations than physical SIMs. On top of this, the component hardware required to power eSIMs is
significantly smaller than even the diminutive nano SIM, making it possible to
install eSIM hardware in devices that would not be physically large enough to
accommodate a traditional SIM or to leave more internal space in larger devices
for components like batteries, memory, or cooling fans.

With an ever-increasing number of machines and devices making use of wireless networks, it can be
increasingly difficult to keep all of these units registered and provisioned
with their respective wireless carriers. Gone are the days when each person had,
at most, a single cellular phone. A decade or so ago, it was hardly considered a
big deal to open your new phone, pop in a square inch-sized SIM card, and begin using it with your subscribed wireless account.
Now, an individual can often have, at any given time, one or more smartphones, a smartwatch, connected earbuds, and more. This is to say nothing
of nearby devices such as home security systems, connected vehicles, and even
connected appliances. In short, the job of keeping all these devices
connected is becoming increasingly complex and harder to manage. Carriers simply
cannot devote the staff necessary to physically install SIM cards into all of
these devices, nor do users want to visit a wireless
carrier’s store every time they want to change the carrier for their many connected devices.

This is where eSIM technology shines. It is capable of providing remote
provisioning and registration capabilities that allow the user and carrier to
register a new device onto the network without any physical interaction with
the device. This applies to both new devices just removed from the
box and used devices that are being transferred to a new networks. While the
benefits to private and business users are obvious,
this capability can be vital to M2M and IoT users.
Where a single private user may have three or four devices to worry about, M2M
and IoT installations can have hundreds or even thousands of devices to
provision and connect. These could range from sensors to smart meters to
connected switches and entire networks of shipping vehicles. In may cases, it
would simply be impractical to require physical interaction with so
many devices in order to connect them to a network. The remote provisioning
capabilities of eSIM technology obviates this need, making it possible for a
person sitting at a PC anywhere in the world to do a job that would have
traditionally required multiple on-site personnel to complete.


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All modern subscriber identity module (SIM) technology is managed by an
organization called the GSM Association (GSMA), a global governing body that tests and
approves various protocols relating to wireless connectivity for mobile devices. The history of eSIM technology began in 2010
when the GSMA revealed that it was exploring a way to create a SIM card based
primarily on software rather than hardware.2 The need for such
technology was nowhere near as urgent as it is today, with only a fraction of
the billions of mobile devices currently in operation existing at that time.
However, the benefits of such a replacement for physical SIM cards was already

The next major milestone in the eventual proliferation of eSIM and eUICC
technology came from the European Commission in 2012 when it chose eUICC chips as the
basis for the in-vehicle emergency system known as eCall.3
This system makes it possible for vehicles involved in accidents or emergencies
to contact emergency services and provide authorities with their current
location. The European Commission was so confident in the ability of eSIM and
eUICC technology to power this emergency call system that it eventually made the
presence of the eCall system mandatory in all vehicles manufactured within the
European Union after April 2018.4

Although the eSIM technology had been
rolled out for industrial applications by 2014, it would be several more years
before a major player in the consumer electronics market brought eSIM’s benefits to the average private
user. As is often the case, Apple was among the earliest companies in the tech
industry to recognize the potential of the new technology, and was the first
major manufacturer to integrate it into their consumer offerings. This began with
the launch of the Apple Watch Series 3, the first model in the company’s
wearable lineup to include its own cellular radio.5 The size of the
Apple Watch would make it difficult for even a nano SIM card to be incorporated
without adding bulk. This made eSIM technology an ideal solution as it
requires only a miniscule onboard chip to power its registration and
provisioning. Along the same lines, the ability of eSIM devices to be
provisioned onto an existing account with an existing phone number made it
possible for buyers of the Series 3 Apple Watch to register their wearable to
the same phone number as their existing iPhone, giving friends and family a
consistent way to connect with them across multiple devices. Although Apple chose to
also use embedded SIM technology in its iPad Pro line, it was not until
2018 that the company launched its first iPhones with eSIM support.6

Because of its decision to wait until the launch of its 2018 iPhone XS, XS
Max, and XR models,
Apple was actually beaten to the punch by Google for having the first
smartphone to support the technology.7 Although the
Google Pixel 2 and Pixel 2 XL both launched with eSIM support built-in, they still relied on traditional nano SIM cards for connectivity to third party carriers. This is because, at the time of their launch in the fall
of 2017, the only carrier that could support the eSIM technology in the Pixel
line was Google’s own Project Fi (now Google Fi). This raises an
important point about eSIM technology: Wireless carriers are
required to specifically add support for it to their networks in order for
those devices supporting it to function properly. While this may be obvious, it should
be readily apparent that this could prove to be a major obstacle for an industry
that has relied on physical SIM technology to provision its devices for multiple
decades. Still, the need to support eSIM tech was given a major shot in the arm
once again by Apple when it joined Google in supporting the protocol with its
iPhone XS and XR lines in 2018.8

Today, Apple continues to evangelize for eSIM technology. Its ability to make
remote provisioning a breeze allows Apple to sell iPhones that can be connected
to the carrier of the user’s choice without
even needing to speak to a customer service rep from either company. Similarly,
the technology’s ability to support multiple subscriber identities on a single
chip means that the company can support the dual-SIM or even triple-SIM setups
(often required by users moving among multiple countries in Europe) without
the need to have multiple physical SIM slots as many of its competitors have
resorted to. Other companies besides Google and Apple have now adopted eSIM
technology as well, including Motorola in its RAZR folding smartphone, Microsoft in its Surface tablet line,
and a range of HP and Lenovo laptops.

eSIMs Vs Physical SIMs

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This section will take a deeper dive into the benefits of eSIM technology and
discuss a few drawbacks in order to help the reader better understand the promise of
this technology.

Figure 1. Physical SIM Card Sizes Compared to
an eUICC Needed for eSIM Support

Figure 1. Physical SIM Card Sizes Compared to an eUICC Needed for eSIM Support

Source: IoT Now


  • Size – As stated above, connected devices are becoming
    smaller and smaller. Whereas 10 or 15 years ago, a cell phone would have
    included more than enough room for a full sized SIM card, today’s
    smartphones are becoming increasingly thin and increasingly powerful. While
    the impact of a device’s thickness may be an obvious reason to require a
    smaller SIM solution, the power consumption of the device is just as
    important. Any space taken up within the device by something
    else, like one or more SIM card slots, is space that can’t be used for more
    battery capacity. Similarly, these increasingly large batteries and their
    increasingly powerful companion processors often require cooling methods
    that their predecessors did not need. In short, the space within all mobile
    devices is always at a premium. The fact that the eUICC chip needed to power
    eSIM technology is only about one tenth of the size of a nano SIM means that
    a significant portion of space can be reclaimed for other uses. Again,
    this is very important for devices as large as smartphones, so it is easy to
    see how that multiplies when talking about products as small
    as smartwatches and connected earpieces.
  • Remote Provisioning – Provisioning is the act of
    registering a device with the carrier network that will provide it with
    connectivity. This has traditionally been handled by a telecom carrier when
    it registers a physical SIM card to a given account. This card can be transferred between devices, automatically providing each device it
    is inserted into with the necessary information needed to connect to the
    owner’s account on that carrier’s network. Registration is required
    for the purposes of connecting (assigning a phone number, allowing for
    mobile data use, etc.) and for billing, as it allows the
    carrier to track the usage of the assigned account and
    compile charges for overages, roaming, and more. As the name would
    suggest, remote provisioning is the act of handling this registration
    process without the need to physically interact with the device. The benefits of this method
    are legion. For
    consumers, it means they can buy a new phone, register with a carrier,
    transfer carriers, and register multiple accounts to a single device
    without the need to install a physical SIM card or go to a carrier
    store. Instead, the user only needs to download the eSIM registration code
    from their carrier(s) to the eUICC already contained within the device.
    Similarly, IoT and M2M deployments can be provisioned en masse by simply
    automating the process of downloading the eSIM registration codes to
    hundreds or thousands of connected devices. Imagine the convenience of
    clicking a link to initiate the provisioning of hundreds of shipping
    container sensors at once, compared to the need to physically install SIM
    cards into each and every one.
  • Security – Where physical SIMs can be cloned, stolen,
    lost, or broken, eSIMs only exist in virtual space. This makes them immune
    to loss or physical theft while also making them safe from many of the
    methods of cloning and electronic theft that traditional SIMs can fall
    victim to. The GSMA itself has stated that eSIMs provide "an equivalent
    level of security and protection to that provided by the
    removable SIM card."9 This is made possible via the use of
    encryption, which is designed to make it nearly impossible for anyone but
    the intended recipient to access the unique registration
    code enclosed within its software. eSIMs also have the potential to curtail
    device theft. Where a physical SIM card can be removed, essentially
    eliminating one of the easiest ways to track a lost or stolen device, an
    eSIM cannot be as easily discarded. An unauthorized users would find
    it nearly impossible to replace the eSIM on a device without interacting with the carrier network in some way.10 If the device
    has been reported as lost or stolen, such interaction could provide
    the true owner, as well as law enforcement authorities, with a way to track
    the device and the thief as well.
  • Flexibility – As stated, eSIMs are capable of being used in any size
    device because of their diminutive physical requirements. But they are also
    capable of being used in multiple devices
    . This is
    because eSIMs can be assigned to a potentially unlimited number of devices
    due to the fact that they are based entirely on software, not hardware.
    This gives users the option to provision multiple phones
    with a single phone number; tie a wearable device into a user’s existing
    account by provisioning it to the same user; and tie numerous IoT or M2M
    deployments to a single account to allow a given command
    to be issued to several devices at once. These tasks would be difficult or impossible
    with a physical SIM.


  • Areas with No Connectivity – Although the eSIM’s
    ability to quickly download a new profile onto a device makes switching to another account potentially easy, it does come with the
    drawback of requiring the device to be powered on and connected
    to a network in order to function. While the proliferation of wireless carrier
    networks and Wi-Fi have rendered this less of an issue than it may once have
    been, the ability to physically swap a SIM card into a new device
    without the need for a present mobile connection is lost when using eSIM
  • Hacking Potential – Due to the digital
    nature of eSIMs, there exists the possibility that a sufficiently
    sophisticated group or individual may crack the encryption used by a
    carrier to distribute its eSIMs. In this case, a malicious third party could
    take control of a user’s device by replacing that user’s eSIM with one of
    their own. Similarly, a hacker could clone the eSIM on a given device over
    the Internet, opening a new avenue for the type of device cloning that may
    once have required physical access to the original device. Thankfully, both
    of these eventualities are made vastly more difficult by a characteristic of
    eSIM technology called Subscription Management Data Protection (SM-DP+).11
    Any changes to a device’s profile requires a
    SM-DP+ check with the device’s carrier. If the request is found to be
    legitimate, the request will proceed and the device will be re-provisioned.
    However, if the request does not pass muster, it will be denied and it could
    potentially be reported to the user or to law enforcement. That said, no
    electronic system is entirely foolproof. eSIM technology remains in its
    infancy, and it is not hard to imagine that hackers are out there champing
    at the bit to find flaws in the protocol that would allow them to bring
    their nefarious intentions to the platform.
  • Carrier Support – Although most carriers support eSIM,
    they have not always rushed to embrace the technology. T-Mobile, for
    example, only agreed to support the technology when it was required to as
    part of its acquisition of Sprint. And even carriers who have offered the
    option are not always up front with customers as to its availability. Analyst
    Lynnette Luna told Fierce Wireless, ““The vast majority of subscribers in the
    US buy a smartphone from their carrier, and all of the US carriers do support
    Apple’s eSIM, so a customer can choose to sign up for service that way. It’s
    not easy as a customer needs to be savvy and look for how to do it on the carrier
    Web sites. It’s not something the big carriers promote.”12 However, this is one
    problem with eSIM technology that will continue to recede as its use becomes
    more mainstream. Until that time, though, it could prove to be an obstacle to a
    user wishing to port their device to a given carrier who has yet to update their
    system. The carriers and manufacturers currently supporting the technology will
    be covered in more depth below.

Despite the few potential hazards that can typically be found in any nascent
technology, it is hard to argue that eSIM technology’s benefits do not outweigh
its drawbacks. Because of this, it will almost certainly continue to grow and
proliferate among wireless carriers and device makers. However, for early
adopters, the important question is: which device makers and carriers are
supporting eSIM technology right now?

Current Support for eSIM Technology

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Figure 2. GSMA’s Graphical Representation of Companies Currently Supporting eSIM Technology

Figure 2. GSMA's Graphical Representation of Companies Currently Supporting eSIM Technology

Source: GSMA

Once again, eSIM technology is still a relative
fledgling when compared to the decades of use that physical SIM cards have under
their belt. That said, the adoption rate for the technology is among the fastest
of any new wireless protocol in recent memory, having gone from 80 manufacturers
to over 130 from 2020 to 2021. Its obvious benefits have drawn major industry players from the telecom carrier arena, IoT
field, and device manufacturing sector to eSIM technology. The list of
participating companies has already far outstripped the ability of this report
to list all of them. However, the following list will attempt to include all of
the most impactful, important, and influential companies currently supporting
eSIM technology.

Carrier Support

  • US – AT&T, T-Mobile, Verizon Wireless
  • Canada – Bell, Fido, Lucky Mobile, Rogers,
  • Europe – 3, Deutsche Telekom, EE, Hrvatski
    Telekom, Movistar, Nokia, O2, Orange, Sunrise, Swisscom, Tele2, Telefonica, Telekom, Telenor, Telia,
    T-Mobile, Vodafone Spain
  • Asia – 1010, 3, Airtel, AIS, APT, csl, China
    Mobile Hong Kong, China Telecom, China Unicom, dtac, du, Etisalat, M1, NTT
    DOCOMO, Reliance Jio, Sony, True Move H, Ooredoo, Smartone, Virgin Mobile, Vodafone
  • Global – Gigsky, Truphone

Manufacturer Support

Apple, Ericsson, Gemalto, Google, HP Enterprise, Huawei, Intel, LG, Qualcomm,
MIcrosoft, Motorola, Nokia, NUU, Samsung, Sony, ARM, and Xiaomi.

This list will likely grow exponentially in the next few years.


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To put it plainly, it is only a matter of time before eSIM technology, either its in current form or in some future iteration, comes
to replace the physical SIM cards. As with any technological transition
that is attempting to replace a protocol that has been entrenched for multiple
decades, this is unlikely to happen overnight. That said, the benefits to
convenience, safety, security, and cost are too numerous and the drawbacks too
few and too minor for any other outcome to appear likely at the moment. Our
world is becoming increasingly reliant on the interconnectivity of myriad
devices. Everything from shipping to medicine to commerce to, of course,
communication now lives or dies on the ability for devices to maintain a connection. Any technology that can ease the process of
connecting new devices and transferring the connectivity of existing devices to
the degree eSIM technology can is a massive boon to a planet that is always
struggling to keep up with its own technological desires and needs. In the next
few years, look for eSIM support to begin popping up in more and more
smartphones, wearables, and even connected smart home devices. It is only a
matter of time before the physical SIM card, in all its various iterations, goes
the way of the floppy disk.



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