Cloud connectivity and SIM

In a previous article, we talked about cloud connectivity and how it is integrated into the MOBA development process. Cloud connectivity is part of the machine-to-machine communication (M2M) in our applications, also on everyone's lips as IoT. A single device like a sensor or a complete system via cloud gateway can be connected to the cloud.

An important aspect of this cloud connectivity is the SIM. To connect a device to the mobile network, a SIM (subscriber identity module) is needed. Regarding the SIM, there are many terms, abbreviations and processes that will be briefly discussed here. 

If we first talk about the physical type of hardware, we will classify the SIM card or the SIM chip. 

The SIM card is the well-known design with its various sizes. The SIM card in cheque card format is probably hardly still known. The subsequent designs became smaller and smaller, from mini-SIM and micro-SIM to nano-SIM. Nowadays SIM cards are supplied universally in the different sizes. You simply take out the appropriate size and insert it into the device, the device. 

With SIM chip, we want to refer to the type of hardware as the soldered component, an integrated circuit chip. This is a chip that is permanently installed in the device. The term eSIM (embedded SIM) is often used synonymously, but eSIM should describe the technology here. 

In terms of size, a SIM chip is smaller than conventional SIM cards. Since no SIM card tray is required, space on the device is saved, allowing a smaller and more robust device design. The SIM chip is integrated into the device, without movable part, ensuring durability. SIM chip is useful for small devices (e. g. sensors) or devices in harsh environments. In addition, the costs of using a SIM chip are lower compared to traditional SIM cards.

From the traditional SIM we come to the eSIM technology. eSIM is a method of identifying the user in the mobile network without a replaceable SIM, a SIM card. This module is either a small physical integrated circuit (SIM chip) or only a software enclave of the system-on-a-chip (SoC). However, since there are also SIM cards available with eSIM technology, to use these advantages in a classic hardware device with card holder. 

What is the difference between eSIM technology and the classic SIM?

While traditional SIM can only store one subscription data tied to a network carrier, eSIM technology can download different subscriber data (so called profiles). This enables the user to easily switch carriers just by changing the settings on their device without changing the physical SIM card. With eSIM, users can seamlessly switch between network operators, even for applications where a reliable signal is required. This is useful for devices that move between locations and different applications.

In principle, two different processes have been established for changing settings. 

In the consumer sector, the process for downloading a desired profile is triggered by the device. This is supported by web portals and QR codes. The QR code contains the URL with access data for downloading a specific profile.

In the M2M sector, this process is triggered by a server. The devices used here do not have a user interface themselves, so it is not possible to use a QR code here, for example.

A new device with eSIM technology comes to the user with a bootstrap connectivity. The bootstrap profile is pre-installed on the device. That is also an essential part of the eSIM technology.

eSIM technology is the future.

The use of an embedded module (as small chip or only as software part) and the technology to download different subscriber data, offers many advantages. Reliability and versatility for the cloud gateway, remote provisioning, seamless switching between networks.