A Complete Guide to SIM Card Specifications: From Standard SIM to eSIM

As a key component for connecting to mobile networks, SIM cards have been constantly evolving in terms of specifications and forms. Different devices support different SIM card specifications, so choosing the right SIM card is crucial. This article will introduce how to select the most suitable SIM card according to application scenarios, especially focusing on IoT SIM card types.

The standard SIM card is the earliest SIM card specification, also known as the large card. It has a size of 25mm × 15mm and was widely used in early devices.

Due to its early emergence, the technology is mature and stable, with low manufacturing costs. Moreover, its thick plastic frame makes it highly resistant to drops and wear, ensuring stability in harsh environments. It is usually applied in some IoT fields where there is no high requirement for device volume and the usage environment is relatively complex. These devices are not sensitive to the space occupied by SIM cards, and some devices need to maintain stable operation in dusty and high-vibration environments. The durability of standard SIM cards can meet such needs, making them a practical choice for industrial IoT equipment.

To adapt to the optimization of internal space in small devices, the micro SIM card came into being. Its size is reduced to 15mm × 12mm, nearly half the size of the standard SIM card, and its chip part is compatible with the standard SIM card.

Compared with the standard SIM card, the micro SIM card is smaller in size, which can save a certain amount of internal space of the device, meeting the design needs of some small and medium-sized IoT devices. It has mature technology and good compatibility. In some small IoT device applications, their design refers to the mainstream SIM card specifications at that time, and the use of micro SIM cards can meet the demand for smaller internal space, making it a suitable option for mid-sized IoT gadgets.

With the increasing demand for internal space, the nano SIM card has become the most mainstream specification at present, with a size of only 12.3mm × 8.8mm, which is the smallest among the three physical SIM cards. The chip area of the nano SIM card is further reduced, and most of the plastic frame is removed, leaving only the chip and a small amount of supporting parts. It is also the mainstream SIM card specification default provided by operators currently, and is widely used in various IoT devices.

It is the most widely used physical SIM card in the current IoT field. Its small size can save the internal space of the device to the greatest extent, making it very suitable for the design of miniaturized IoT devices. Due to the simplified structure, it is more flexible to install inside the device, which helps to optimize the overall layout of the device, making it an ideal choice for compact IoT equipment.

The eSIM card is an embedded SIM card. Unlike the above physical SIM cards, it has no physical form. Instead, the SIM card information is directly integrated into the device's chip. Users do not need to manually insert a physical SIM card. They only need to use the operator's over-the-air card writing technology to write the number information into the device to activate it, which is a revolutionary innovation in IoT connectivity.

The eSIM card has a broad application prospect in the emerging IoT field. Its non-physical form greatly promotes the miniaturization and integration design of IoT devices, avoids the problems of poor contact and wear caused by plugging and unplugging physical cards, and improves the stability and service life of the devices. It also supports remote control and network switching, which is convenient for the management and operation of large-scale IoT devices, reduces maintenance costs and improves tracking efficiency, making embedded SIM for IoT a future trend.

The specifications of SIM cards have gradually evolved from the initial standard card to Micro SIM, Nano SIM, and now eSIM. Each change conforms to the development trend of mobile devices towards being thinner, lighter and smarter. Different specifications of SIM cards have their own applicable scenarios, advantages and disadvantages. Understanding these characteristics helps us make more appropriate choices in IoT device selection, deployment and maintenance. In the future, with the further maturity of eSIM technology, its application in the IoT field will continue to expand, bringing more convenient and efficient solutions to the development of the IoT industry, especially for IoT SIM card applications.

Metrio Aero Core, as a leader in the IoT industry, has witnessed the evolution and development of SIM cards and has the ability to match the most suitable SIM card solutions for customers in different scenarios. If you are currently worried about choosing a SIM card, you may wish to obtain free professional consulting advice from Metrio Aero Core, your trusted partner for IoT SIM card selection.