What Are The Differences Between SIM, eSIM, and iSIM?

These SIM, eSIM, and iSIM integrate the evolution of the customer identification standard in mobile telephony and also drive the Internet of Things. From its primary version, the SIM card solved the protection and activation of the service code of the subscribers to the operators.

SIM

Subscriber Identity Module, the SIM card that is a removable smart card and has been used in all types of mobile communication devices. In general, it fits into a slot that has a chip reader, on the inside of these computers.

SIM is indispensable in the GSM communication network since it emerged as the first standard of digital mobile telephony in 1991. With the SIM card, the new generation of mobiles got rid of the identifier on the network. From that moment on, users were able to change their phone or provider just by changing the card.

In addition, this is the technology that allowed the mobile to include additional functions such as text messaging, storage, tones, games, and other multimedia applications. Similarly, the SIM underwent an evolution in size and capabilities. The 1991 version had the dimensions of a bank card: 85.60 x 53.98 mm and 0.76 mm thick. The size was according to the first mobile phones compatible with GSM, which had the space for this card.

eSIM

eSIM is the next step in SIM, eSIM, and iSIM transformation. The number of people connected to the Internet increases daily, as does the demand for more ergonomic and multifunctional mobile devices. At the same time, the development of IoT M2M communications allows the control of various remote devices through mobile phones and other terminals. For these reasons, the traditional SIM card had to evolve to a smaller and more secure system for the user.

The eSIM was the answer to this demand as of 2016 and is now a link in the SIM, eSIM, and iSIM chain. Contradictory as it may seem, this component is factory installed on smartphones, smartwatches, and other equipment. Still, it is virtual and its size is 90% smaller than a Nano-SIM.

In other words: 6 x 5 mm, which makes it possible to dispense with the removable physical card. ESIM has the same purpose as the SIM card: to authenticate the customer’s identity and give him access to the services of his telecommunications company. 

However, there is another important difference; As it is an inseparable part of the device, its configuration is remote. It is even reprogrammable at the same time. On the other hand, the security of the terminals connected through eSIM is another aspect to consider. 

The component is permanently welded to the unit and any attempt to remove it is remotely detected. For this reason, eSIM is the authentication and connectivity system currently used in devices for the control of assets and vehicle fleets. 

iSIM

The need to optimize the functions of such an essential component as the SIM in minimal spaces encourages the development of the iSIM. This advancement in SIM, eSIM, and iSIM continuity is not yet standardized like eSIM. Still, it is already making SIM hardware part of the SoC or system on chip of mobile processors and modems. For this reason, the iSIM is much smaller in size and does not require a separate processor as with the eSIM. 

In this case, we are talking about a not yet established fraction of a square millimeter. In other words: SIM capabilities are “fused” in the device’s processor. Thus, they acquire a high level of security and guarantee continuity in their operation. It should be noted that this integration into the hardware architecture of the terminals substantially reduces manufacturing costs. 

This is a positive feature in terms of the expansion of IoT devices since they are more accessible to a greater number of users. Likewise, this outlook is favorable depending on the amount of equipment connected to IoT.