SIM chips...

[RichD]

I recently switched phone providers, replacing the SIM chip.
Which got me wondering an old wonderment: what\'s inside?

It\'s remarkable that the industry has standardized on a
single form factor and pin out. But I\'m curious, what
is the separation of functions, between the chip and the
surrounding device? How to characterize it as a black box,
what exactly are the signals which flow across the pins?
Do any of those pins carry analog waveforms?

I figure this is a reasonable place to ask such a question -

--
Rich

 

[Lasse Langwadt Christensen]

torsdag den 14. september 2023 kl. 19.58.07 UTC+2 skrev RichD:

I recently switched phone providers, replacing the SIM chip.
Which got me wondering an old wonderment: what\'s inside?

It\'s remarkable that the industry has standardized on a
single form factor and pin out. But I\'m curious, what
is the separation of functions, between the chip and the
surrounding device? How to characterize it as a black box,
what exactly are the signals which flow across the pins?
Do any of those pins carry analog waveforms?

I figure this is a reasonable place to ask such a question -

I wonder if maybe, just maybe, google will have an idea, .. https://en.wikipedia.org/wiki/SIM_card

 

[Michael Terrell]

On Thursday, September 14, 2023 at 1:58:07 PM UTC-4, RichD wrote:

I recently switched phone providers, replacing the SIM chip.
Which got me wondering an old wonderment: what\'s inside?

It\'s remarkable that the industry has standardized on a
single form factor and pin out. But I\'m curious, what
is the separation of functions, between the chip and the
surrounding device? How to characterize it as a black box,
what exactly are the signals which flow across the pins?
Do any of those pins carry analog waveforms?

I figure this is a reasonable place to ask such a question -

--
Rich

You can buy a USB adapter, that comes with software to read the content.

 

[Martin Brown]

On 17/09/2023 15:43, Michael Terrell wrote:

On Thursday, September 14, 2023 at 1:58:07 PM UTC-4, RichD wrote:
I recently switched phone providers, replacing the SIM chip.
Which got me wondering an old wonderment: what\'s inside?

It\'s remarkable that the industry has standardized on a
single form factor and pin out. But I\'m curious, what
is the separation of functions, between the chip and the
surrounding device? How to characterize it as a black box,
what exactly are the signals which flow across the pins?
Do any of those pins carry analog waveforms?

I figure this is a reasonable place to ask such a question -

--
Rich
You can buy a USB adapter, that comes with software to read the content.

Modern mobile phones also offer eSIMs with no physical card at all.

--
Martin Brown

 

[RichD]

On September 17, Martin Brown wrote:

It\'s remarkable that the industry has standardized on a
single form factor and pin out. But I\'m curious, what
is the separation of functions, between the chip and the
surrounding device? How to characterize it as a black box,
what exactly are the signals which flow across the pins?
Do any of those pins carry analog waveforms?

You can buy a USB adapter, that comes with software to read the content.

Modern mobile phones also offer eSIMs with no physical card at all.

A SIM chip can be replaced by software? I thought they had
rf detectors inside, TDM, FDM, CDM...

--
Rich

 

[Lasse Langwadt Christensen]

fredag den 22. september 2023 kl. 22.47.14 UTC+2 skrev RichD:

On September 17, Martin Brown wrote:
It\'s remarkable that the industry has standardized on a
single form factor and pin out. But I\'m curious, what
is the separation of functions, between the chip and the
surrounding device? How to characterize it as a black box,
what exactly are the signals which flow across the pins?
Do any of those pins carry analog waveforms?

You can buy a USB adapter, that comes with software to read the content.

Modern mobile phones also offer eSIMs with no physical card at all.
A SIM chip can be replaced by software? I thought they had
rf detectors inside, TDM, FDM, CDM...

no, it is only a bit of data to identify you on the network

 

[RichD]

On September 23, Lasse Langwadt Christensen wrote:

You can buy a USB adapter, that comes with software to read the content.

Modern mobile phones also offer eSIMs with no physical card at all.

A SIM chip can be replaced by software? I thought they had
rf detectors inside, TDM, FDM, CDM...

no, it is only a bit of data to identify you on the network

I know Qualcomm is a big player. I thought their CDM devices are
inside the SIM chips.

What exactly are they selling then?

--
Rich

 

[Lasse Langwadt Christensen]

søndag den 24. september 2023 kl. 01.34.21 UTC+2 skrev RichD:

On September 23, Lasse Langwadt Christensen wrote:
You can buy a USB adapter, that comes with software to read the content.

Modern mobile phones also offer eSIMs with no physical card at all.

A SIM chip can be replaced by software? I thought they had
rf detectors inside, TDM, FDM, CDM...

no, it is only a bit of data to identify you on the network
I know Qualcomm is a big player. I thought their CDM devices are
inside the SIM chips.

no, https://en.wikipedia.org/wiki/SIM_card

What exactly are they selling then?

The main chips that makes up the functionality of a cellphone
the SIM card is only a bit of encrypted data to identify you on
the network

the phone doesn\'t need a SIM card to make calls, you can call 911/112
without a SIM card