eSIM simplified: a quick guide to consumer eSIM-ready IoT device activation | Default SM-DP+ address & Root Discovery Service | Blog series (3/3)

Last updated: 06 December 2021


< 4-minute read.

In the second blog in my series dedicated to consumer eSIM-device activation, I ended by reflecting on how the whole mobile industry is now focusing on the eSIM customer experience.

Indeed SIM card dematerialization represents a true Big Bang for mobile operators because it constitutes the digitalization of the connectivity distribution. As the SIM’s worthy heir, the eSIM has to bring this customer experience to a new level in terms of simplicity of user and freedom of service.

Let’s jump now to the second option to activate a consumer eSIM device:

the SM-DP+ address set by default in the eUICC

How does it work?

It consists in pre-provisioning the device’s eUICC with the operator’s remote SIM provisioning platform (SM-DP+) address during the device manufacturing stage. Consequently, once switched on for the first time, the device directly connects to the SM-DP+ server to retrieve its full eSIM profile.

What’s the main benefit?

It makes adoption and activation of eSIM technology simpler thanks to an excellent customer experience.

What are the requirements?

  1. Mobile operators need to work closely with OEMs to customize the devices to their network. It may generate non-negligible inventory and supply chain costs compared to vanilla open market devices.
  2. A primary connection is still required for attaching the device to the network’s SM-DP+ server.
  3. This mechanism only works for operator-subsidized eSIM-enabled handsets, as the user has to buy the operator’s subsidized handset together with the mobile operator’s subscription. Thus it is a perfect fit for markets with a high post-paid penetration, such as the US.

It is no surprise to find that this activation scheme widely used in Noram; it’s very close to CDMA device activation in which a device was intended to work with a given mobile network.

In order to continuously improve both user simplicity of use and freedom of service, a third mode has come:

GSMA’s Root Discovery service-based eSIM activation

Since the second semester of 2017, a third option exists to remotely activate a consumer eSIM-capable device. It is called the Subscription Management Root-Discovery Service (i.e. SM-DS); indeed it intends to further enhance the customer experience of connecting an open market consumer eSIM device to the mobile network with the offer of the user’s choice.

How does the Root Discovery Service work?

In this case, the user purchases separately her/his eSIM-based mobile subscription and smartphone. Once switched on for the first time, the device will automatically and instantly retrieve over-the-air the eSIM profile (corresponding to the mobile subscription just bought by the user) destined for the device.

When the user buys her/his subscription at POS or online, the device box barcode (aka EID, i.e. eUICC identity) is retrieved (by scan of typing) and then stored into the SM-DP+. At this point, the SM-DS come into play: the corresponding EID and SM-DP+ address are registered into the SM-DS, which simply aims at liaising the device’s eUICC with the eSIM profile provided by the SM-DP+.

This is where SMDS Connect comes into play. It provides the means of automatically connecting a mobile operator’s backend system to the previous described GSMA’s Root Discovery Service and all other deployed proprietary Discovery Services.

What are the Root Discovery services benefits?

  • It provides a true out-of-the-box mobile subscription activation and makes adoption of eSIM technology a lot simpler for end-users.
  • It also relieves points of sales and users as it does not require to issue and/or stamp the QR activation code.

What are the requirements?

Alike for the QR code activation:

  • A minimum first level of native connectivity for the devices for attaching the smartphone with the SM-DS platform.
  • LPA to be supported by the device.

Mobile operators and other mobile connectivity providers (e.g. Transatel) must also connect their SM-DP+ platform to the SM-DS platform. So far, the GSMA-Root Discovery Service is provided by the GSMA.


The SIM card has brought simplicity and freedom of providing connectivity separately from the device to billions of people worldwide. Since the eSIM’s inception, the whole industry has been working –and will continue to work– to reinvent elegant nature of the SIM in a fully digital world. So far there are 4 ways to activate eSIM-capable consumer IoT devices. And probably other ways will come further in a near future.

What’s your experience about the Root Discovery service? What could be other alternatives to activate eSIM-equipped consumer device? Leave your comments below or tweet to me /us at @ThalesDigiSec.

If you’re interested in the topic, feel free to read my other blogs on eSIM here:

7 thoughts on “eSIM simplified: a quick guide to consumer eSIM-ready IoT device activation | Default SM-DP+ address & Root Discovery Service | Blog series (3/3)

  1. Excellent post! Silly question (since I am new to the topic): in case of theft, how can I retrieve my profile stored on SM-DP+ if the mapping is done using EID?

    In essence, how can I retrieve my profile once I have lost my phone?
    Is there flexibility to map: EID – IMSI – Profile?

  2. Hi! I hear that it is also possible to activate an eSIM profile via an operator App. For instance, GigSky you sell you an international data plan through an eSIM profile they install on your phone..
    How does this work? Is it safe?

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