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Ever wonder how much of this world you really understand?
I am talking about the Technological world we are immersed into already. Take your mobile phone for instance... do you really understand how it functions?
Take the lowly SIM card, did you know that is stands for Subscriber Identity Module or subscriber identification module (SIM), most know its required for phone operations, but little beyond that.
How does it function?
SIM is an integrated circuit (IC), Its actually its own little computer, yeah that sounds sophisticated... did you know it runs its own Operating System?
- It is known as CardOS and the function of the OS is to securely store the international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers).
- Yes, your mobile phone is a mobile computer, and you might understand that you can swap it between devices with ease. (More powerful than the computers US used to send astronauts to space right in the palm of your hand).
Currently there are several-sizes for SIM cards some examples are below
Standard has the size of 15mm x 25mm
micro has the size of 12mm x 15mm
Nano has the size of 8.8mm x 12.3mm
eSIM has the size of 2.5mm x 2.3mm
Did you know that the SIM card has a structure for each segment on that card? Each segment playing a specific purpose to assist the mobile devices operation(s).
The areas are broken down into (not listed in order from the card) the following:
- Clock - need a clock to keep track of several variables and allows for sync state and tracking
- GND - ground reference for the IC (ah yes, good ole reliable ground)
- I/O - I think back to late 90's and early 00's when my kid was sending 1000's of text messages a day (yes a day) and would complain about performance degradation. It took me a few minutes to put it together that the I/O space has a limited Read/Write capability and with the quantity of SMS being created, concurrently managed (i.e. live chats) and then delete functions those older cards and phones were putting in some serious I/O
- Vcc - Voltage supplied
- Vpp - programming power voltage
- Optional Pad for USB - think future use area
- Optional Pad for USB - think future use area
- Reset - ah yes the good ole reset to factory - fix all my problems segment
So how does your daily life hit your SIM card? Are you a nice consumer or a heavy handed consumer? What IF, people start trying to run / mine Crypto from their Phones. Think back to mid-2020 when investigative journalist reporter mentioned that all Samsung Mobile Phones will be able to run a THETA Edge node. Doesn't sound so far off now does it. I would envision the Optional USB areas would we called into use for these types of operations.
- life is fascinating with all the inventions that we leverage without fully understanding nor really needing to understand to gain benefits to our daily lives. Stay curious friends.
