Cellular connectivity is one essential way to connect IoT devices, for which a SIM card is a necessity.
SIM is an acronym for a subscriber identity module or subscriber identification module. A SIM card is an integrated circuit with a card operating system (COS). It is designed to securely store the international mobile subscriber identity (IMSI) number and its associated key, which are used to identify and authenticate subscribers on mobile IoT devices.
What are the differences between SIM cards?
Suppose you’re designing a device that relies on cellular connectivity. In that case, you should be aware of the many SIM form factors available so that you can make the optimal option and design accordingly.
SIM form factors are the defined sizes produced by subscriber identity modules (SIMs). SIM form factors are classified as 1FF, 2FF, 3FF, 4FF, and MFF2. Each SIM generation is smaller than the previous one. MFF2 is an abbreviation for the machine-to-machine form factor.
All the form factors have the same capabilities, but their proportions change, making them more appropriate for devices. 2FF, 3FF, and 4FF SIMs must be inserted into a device; however, MFF2 SIMs must be embedded, which is why they are also known as eSIMs, and 1FF SIM cards are no longer in use. While they are commonly referred to by the generation (1, 2, 3, 4), subsequent SIMs are sometimes referred to as “mini SIMs” (2FF), “micro SIMs” (3FF), “nano SIMs” (4FF), and “eSIMs” or “embedded SIMs” (MFF2).
What are the sizes of SIMs available?
The dimensions of each form factor are as follows:
- 1FF: 85.6mm × 53.98mm × 0.76mm
- 2FF (Mini): 25mm x 15mm x 0.76mm
- 3FF (Micro): 15mm x 12mm x 0.76mm
- 4FF (Nano): 12.3mm × 8.8mm × 0.67mm
- MFF2 (eSIM): 5mm x 6 mm x 1mm
Even though the name of the 2FF form factor includes the word “small,” it is the largest in size form factor choice available today. As a result, it is best suited for bigger equipment like ATMs, amusement park attractions, or vending machines.
The 4FF form factor or Nano SIMs are considerably smaller and narrower than their predecessors. Therefore, it is an excellent networking solution for small IoT or M2M devices like wearables or mobile payment devices.
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