What is eSIM, and how does it work?

ESIM stands for the embedded sim. It is also called eUICC (embedded Universal Circuit Card). The new iPhone models include eSIM support as a substitute for a second SIM. The regular SIM is a small external electronic chip that stores the subscription profile for a mobile subscriber. The profile includes IMSI, ICCID, authentication information, etc. eSIM is similar to SIM functionally, but an embedded chip inside the device is re-writable by the mobile operator. When a mobile user changes service provider, buying a new sim card is unnecessary. The subscription will be written by the new mobile operator over the air. To support eSIM functionality, the mobile operator should also support provisioning over the air. 

Advantages of eSIM:

  1. No need to change the sim card for a new mobile operator.
  2. MVNO can provide low-cost roaming in all countries.
  3. No need to cut the sim card to fix the sim size as per slots in the handset.
  4. The subscriber does not worry about the damage to the sim card. The phones are mostly waterproof. So if the sim is inside the phone, there is no need to worry about external damage.
  5. A mobile operator does not need to manufacture so many sim cards. This reduces the cost of manufacturing and distribution. 
  6. No need to wait for the new sim card to switch to another mobile operator.

Above, we have talked about the many advantages of new technology. But there is a disadvantage too. Only a few support eSIM. Because of this, device manufacturers need to support both sim types.

M2M and IoT advantages with eSIM:

M2M and IoT are two new concepts for connected devices. You might know that new gadgets are coming with IoT features. What are these features do for you? A car with a vehicle tracking system is an example of IoT. For tracking, devices read the data for positioning. This could be from GPS or the cell of a mobile network. Devices push the data to the server. On the server, an application can get the tracking information. For data, the device should have a sim card.

If the device has a standard sim card, then the device should be updated manually if the tracing service provider wants to change the mobile operator. Change may be due to costly or poor services or lack of coverage in some areas. If the device has an eSIM, the service provider can change sim information over the air. This encourages IoT and m2m devices to use eSIM.

MVNOs and eSIM:

MVNO, or Mobile Virtual Network Operator, is similar to a regular mobile network operator. But do not have a spectrum license, so they will not have mobile towers. With the advantage of multi-IMSI sim cards, MVNOs take advantage of low-cost roaming across the globe. When a subscriber moves to a new location/country, the local IMSI of that country/location gets activated. This makes subscribers local, so there is no high roaming cost. For example, if a UK-based MVNO is providing low-cost roaming for India. Then sim card will have IMSI from an Indian mobile operator, UK IMSI, and other IMSIs. When a subscriber moves to India, the Indian IMSI will get active, and the sim will be local to India. Results in low-cost calls and other services.

The problem with SIM for MVNO is the number of IMSIs a sim can have. It limits the low-cost roaming to fewer countries only. With the eSIM, IMSIs are configured over the air (no limitation on the number of IMSIs). Enables roaming in all countries.

How do subscribers activate new sim details?

After eSIM switching to a new mobile operator differs from a regular SIM. First, a subscriber needs to check for eSim support in a mobile network. If the operator has support, the subscriber can install an app or buy a card from the store with a bar code. A new profile in eSIM can be activated from a mobile app or via a scanning bar code.