What is eSIM? iPhone starts eSIM support


I’ve heard the word “eSIM” a lot lately, but it’s likely to be a big factor that eSIM has been supported since iPhone XS/XR.

Originally, in Japan, the users were not aware of the SIM because telecommunication carriers sell both a smartphone device and a SIM card as a package with SIM lock. However, with the iPhone equipped with eSIM and the recent popularity of MVNO smartphones, people are becoming more interested in SIMs than before.

SIM stands for Subscriber Identity Module Card and is primarily used for authentication for users to communicate. Therefore, the SIM card contains some information for authentication, primarily ICCID, IMSI, and MSISDN.

There are several types of SIM cards, but they are divided into two parts, one is a physical SIM made of plastic, and the other is a SIM of software called eSIM, which we’ll show you in this article.

eSIM stands for embedded SIM and is a software-controlled SIM, not a physical card, and is pre-built into the device. You can download the required data from the communication network to the eSIM built into this device and use it like a physical SIM card.


Benefits of using eSIM

One of the great benefits of eSIM is that it doesn’t require physical space for the SIM card.

Usually, if it is a smartphone a slot is available to put the SIM card in, but the eSIM eliminates the need for this SIM card slot. Among modern smartphones, there are some dual SIM-enabled smartphones that can use two SIM cards, but instead of 2 SIM card slots for iPhones, one supports physical SIM and the other supports eSIM. Normally, dual SIMs require two SIM card slots, but eSIM has the advantage of maintaining the design of your smartphone without the need for a new SIM card slot.

In addition, it may not be difficult to prepare the SIM card slot if it is a smartphone, but for IoT devices, the size of the device is small, so it’s often difficult to prepare a SIM card slot in the first place. eSIM is especially useful for things that are difficult to provide SIM card slots, such as sensor IoT and wearables, which will expand more and more in the future.

 Another benefit of eSIM is that it allows you to change the carrier to which you are contracting at the user’s initiative. Typically, when you change the carrier that the user contracts, you receive a SIM card from the destination carrier and replace the SIM card to change the carrier, but in the case of eSIM, it is possible to change the carrier that the user contracts by the user’s action on the terminal.

Users don’t change carriers that often, so I think some people think that eSIM is unnecessary. But what if, for example, you go abroad?

If you are going abroad in a short period of time, such as an overseas trip or a business trip abroad, you can prepare rental Wi-Fi router for overseas these days. By using eSIM instead of this Wi-Fi router, users can download profiles (data required for communication) to be used by eSIM before traveling abroad, and then switch to eSIM profile when they arrive there.

One of the benefits of this is the cost. Wi-Fi routers are cheaper than using the carrier’s international roaming service, but they still cost between 1,500 and 2,000 JPY per day, so a week’s travel abroad costs more than 10,000 JPY. Moreover, since the traveling time is included in the period from the start to the end of the rental, the real day unit price will be considerably higher.

Carriers in Hong Kong Three’s overseas data eSIM can communicate up to 4GB of data in many countries, including the United States, Australia, and France, and is less than 2,000 JPY for plans with a seven-day expiration date.

You can also purchase and use SIMs locally abroad, but it’s very convenient to be able to pre-configure them with eSIM, considering the hassle of visiting the shop where the SIM card is sold and setting it up locally.


How does eSIM work?

Let’s take a quick look at how eSIM works.

Users need to obtain the information (profile) for eSIM provisioning but there are two main ways to get this information.

One is use of QR code. The carrier provides a QR code for connecting to the server (SM-DP+) for eSIM users to register, and the user can connect to SM-DP+ by reading the QR code.

Another way is to use a dedicated app. Some carriers offer dedicated applications for registering eSIM users. Users will be able to connect to SM-DP+ by downloading a dedicated app in advance and using this application.

After connecting to SM-DP+, download the profile information required for communication and install it on your device. All the information required for communication is written to the eSIM (eUICC) of the terminal, allowing the user to communicate with this carrier. (Depending on your carrier and terminal type, you may need to configure additional APNs, etc.))

It’s very easy to switch carriers with eSIM.


The Reality and Future of eSIM

eSIM is very easy for users to switch between carriers, which is a very useful feature, but it is not yet popular in Japan. Why is that?

In order to use eSIM, carriers must have an eSIM-enabled network, but major carriers in the country do not provide eSIM services available in the country. This is because eSIM, which is useful to users, is a threat from the carrier’s point of view.

The fact that users can easily switch carriers means that users can easily switch to other carriers. In the past, carriers have focused on how to prevent subscribers from canceling (migrating to other carriers), and have focused on preventing cancellations by using a variety of means, such as SIM locks that can block to use the device with other SIM cards, or two-year contract binding.  Opening up the use of eSIM means implementing measures that are completely the opposite of previous measures, and therefore, from the standpoint of telecommunications carriers, carriers don’t want to actively use eSIM in Japan.

Because of this situation, it seems to be difficult for eSM to be flying for smartphone in Japan. On the other hand, since many overseas carriers already offer eSIM services, and domestic carriers also offer eSIM services for only overseas travel, the main purpose of eSIM for the time being will be to use it when traveling abroad. However, since iPhone XS and XR and later support eSIM, and the number of devices that can use eSIM will surely increase in the future, the environment in which eSIM can be used may change suddenly accordingly, and it is still a situation to keep an eye on.