SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

Didrik Rokhaug — Tue, 30 Apr 2024 13:02:37 GMT

[quote user="Didrik Rokhaug"]As far as I know (I will try to get this confirmed though) there is no standard interface for SoftSIMs.[/quote]

Our SIM expert also doesn't know of any standard interface for SoftSIMs.

[quote user="Didrik Rokhaug"]

papatel said:
Regarding the response from your SIM expert, I'm trying to read between the lines that proper implementations of suspend don't actually wear out the flash while SIM shutfoff certainly can. Can you please check that this assumption is correct?

I will check and come back to you.

[/quote]

"Suspend uses flash to store the internal state of SIM card, so I think that a proper implementation could be expected to tolerate large number of write cycles. Such SIM card should not wear out too soon due to use of suspend functionality for power saving."

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

Didrik Rokhaug — Mon, 29 Apr 2024 16:38:28 GMT

[quote user="papatel"]After further research I believe that Noridic is offering access to its SoftSIM platform to everyone who wants it. It's just that this is not likely a standard that will be widely accepted outside of Nordic (not GSMA adopted) so it's hard for MVNO's and carriers to justify the implementation work until there is a critical mass of adopters.[/quote]

As far as I know (I will try to get this confirmed though) there is no standard interface for SoftSIMs. Though even if it were, there would probably be some porting needed anyway, to adapt a particular SoftSIM solution to the relevant HW and SW platform.

[quote user="papatel"]Onomondo may just be the first instance and more will follow with time. Either way, this is super concerning and I'm not sure we will use Nordic's SoftSIM offering. My company is looking 5 years down the line and having several million devices deployed on a dead SoftSIM platform doesn't seem particularly appealing.[/quote]

If you haven't already, I recommend you take this up with your local sales representative. They should have a better overview of any other potentila SoftSIM providers. If you don't know how to contact your local sales representative, you can send me a private message with your location, and I will provide the contact details.

[quote user="papatel"]Or when we have connectivity problems we don't get support from network providers.[/quote]

In my experience, Onomondo is quite helpful when it comes to looking into connectivity problems, and on their web platform you can get network logs. Though as an MVNO, they of course only cover the core network. If you are thinking of RAN problems, you will have the same problem with any MVNO regardless of the type of SIM, and similarly if you use an MNO, but are roaming on a different network.

[quote user="papatel"]Regarding the response from your SIM expert, I'm trying to read between the lines that proper implementations of suspend don't actually wear out the flash while SIM shutfoff certainly can. Can you please check that this assumption is correct? [/quote]

I will check and come back to you.

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

papatel — Sun, 28 Apr 2024 03:57:33 GMT

Hello Didrik,

You make some valid points about SIM concerns being outside the scope of Nordic semiconductor.

Regarding the response from your SIM expert, I'm trying to read between the lines that proper implementations of suspend don't actually wear out the flash while SIM shutfoff certainly can. Can you please check that this assumption is correct? I believe clarifying this question will help guide integrators tremendously. More importantly high volume customers can influence the industry in a positive manner by selecting SIM manufacturers that support this valuable feature. But if you are saying SIM suspend is no better than SIM shutoff then we can stop wasting time on the subject. This is how Mihir and I interpreted your comment and why we are worried:

"Not all SIM cards allows you to turn them off (using either suspend or deactivate) during eDRX, as that would wear out their flash too quickly, leaving you with an unusable SIM card (and product)."

I really appreciate your comments regarding Nordic SoftSIM. I will ask my Nordic and MVNO representatives more clearly on this point.

After further research I believe that Noridic is offering access to its SoftSIM platform to everyone who wants it. It's just that this is not likely a standard that will be widely accepted outside of Nordic (not GSMA adopted) so it's hard for MVNO's and carriers to justify the implementation work until there is a critical mass of adopters. Onomondo may just be the first instance and more will follow with time. Either way, this is super concerning and I'm not sure we will use Nordic's SoftSIM offering. My company is looking 5 years down the line and having several million devices deployed on a dead SoftSIM platform doesn't seem particularly appealing. Or when we have connectivity problems we don't get support from network providers. Maybe I just need an education that will explain my concerns away?

I'm hope my rambling here at least conveys that there isn't enough clear information about Nordic's Soft SIM and how it sits in the industry.

So full circle, I need answers on SIM suspend concerns. Our MVNO has confirmed this feature is supported (we don't need to force SIM shutoff). I will reach out to the SIM manufacturer itself if we can't get Nordic to answer this question more broadly for the community at least for the most common SIM hardware used by its customers.

Nordic an excellent Onomondo reference for SoftSIM implementation, I'm asking for the same toward a proper implementation of SIM Suspend that won't lead to premature connectivity failure.

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

Didrik Rokhaug — Fri, 26 Apr 2024 13:38:09 GMT

[quote user="papatel"]

We do have a question regarding suspend vs sim shutoff. If your comment about wearing flash out applies even to proper implementations of the suspend command, that is an alarming concern. There are a ton of factors here to consider for a physical SIM:

Endurance cycle, industrial MFF2 sims claim 500MM write cycles
Flash wear level implementation
Flash size (larger flash means less wear per cell if you have good wear leveling implemented)

[/quote]

Questions about flash wear leveling, etc. you have to take with the SIM card provider. That is SIM card internal functionality that our modem has no control over.

I also checked with our SIM expert about why SIM cards does not allow deactivation. This was his response:

"I’m not very well aware why deactivation is not allowed by many SIM cards. Haven’t heard card provider’s statements related to that.

I suppose one reason could be concerns about toolkit application functionality. They get shut down and restarted every time when SIM card is deactivated/activated. Suspend is an improvement to that since it allows the SIM card to store it’s internal state before deactivation and continue from same situation after activation. It requires also implementation on SIM card side, and it looks like very few SIM cards have that done."

[quote user="papatel"]Given that SoftSim makes this feature obsolete and has several other advantages, I'd really appreciate candid updates on that front. The community wants it yet there is so little information coming from Nordic on the subject. If the strategy is to herd people toward using Onomondo, that is something we need to understand now.[/quote]

Can you be more specific about what information you think is missing?

Questions about our roadmap should be taken to your local sales representative. I am not at liberty to discuss those details.

Our interface SoftSIM interface should support SoftSIMs from any provider. However, it is up to each provider if they want to provide SoftSIMs, and what platforms to support. Onomondo is the first to be generally available (at least as far as I know), and information about their solution is also easily available, which is why they are usually used as the example.

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

papatel — Thu, 25 Apr 2024 15:51:10 GMT

Hello Didrik,

Thank you again for your response. Given that SoftSim makes this feature obsolete and has several other advantages, I'd really appreciate candid updates on that front. The community wants it yet there is so little information coming from Nordic on the subject. If the strategy is to herd people toward using Onomondo, that is something we need to understand now.

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

Didrik Rokhaug — Thu, 25 Apr 2024 14:23:51 GMT

[quote user="papatel"]I'd first like to point out that the form factor does indeed make implications on the endurance capability of the NVRAM. *Usually* MFF2 sims have a significantly higher endurance rating than their plastic counter parts. [/quote]

While MFF2 SIMs often have higher endurance ratings, my point is that there isn't, as far as I know, nothing inherent in the MFF2 form factor that makes it true. You can have plastic SIMs with high endurance rating, and MFF2s with low ratings.

Any writing to flash will contribute to the flash wear, though as you say, there are many factors that contribute to how big of an issue this is.

[quote user="papatel"]The best solution would be a software SIM but I'm not getting any answers from my contacts at Nordic or our MVNO as to when that feature will be available.[/quote]

SoftSIM is been supported on the nRF9160 and nRF91x1 devices.

I don't have a full overview of which operators are working on providing it, but at the moment, it is available from at least Onomondo and IIJ:

https://onomondo.com/product/softsim-for-nordic-semiconductor/

https://www.iij.ad.jp/en/news/pressrelease/2024/0226.html

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

papatel — Wed, 24 Apr 2024 10:58:10 GMT

Hello Didrik,
I'd first like to point out that the form factor does indeed make implications on the endurance capability of the NVRAM. *Usually* MFF2 sims have a significantly higher endurance rating than their plastic counter parts.

Endurance cycle, industrial MFF2 sims claim 500MM write cycles
Flash wear level implementation
Flash size (larger flash means less wear per cell if you have good wear leveling implemented)

My point is that Nordic should have good answers to these questions. I really request we get a full answer on this from the Nordic team. I will in parallel ask our MVNO to also consider these points.

The best solution would be a software SIM but I'm not getting any answers from my contacts at Nordic or our MVNO as to when that feature will be available.

Thank you!

-Patrick.

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

Didrik Rokhaug — Mon, 22 Apr 2024 13:11:58 GMT

I don't think the form factor of the SIM affects anything.

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

mnjLC — Mon, 22 Apr 2024 11:16:13 GMT

Hello Didrik,

We use MFF2 style hardware sims. Currently we are shutting down the sims ( at+ssrda=0,1,0 ) during the e-drx cycles. Will that also affect the flash on these type of sims?

Thanks!

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

mnjLC — Fri, 15 Mar 2024 10:15:54 GMT

Thanks!

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

Didrik Rokhaug — Fri, 15 Mar 2024 10:14:49 GMT

Yes, both those features are dependent on the EF-AD.

Not all SIM cards allows you to turn them off (using either suspend or deactivate) during eDRX, as that would wear out their flash too quickly, leaving you with an unusable SIM card (and product).

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

mnjLC — Fri, 15 Mar 2024 10:05:01 GMT

Hi,

We see that there are two options +SSRDA at command,

1) suspend and resume UICC.

2) deactivate and activate UICC

Are both the mentioned options dependent on EF-AD ? From my understanding, deactivate and activate should work regardless of EF-AD register status.

[quote userid="81181" url="~/f/nordic-q-a/109113/sim-shutdown-does-not-happen-during-the-e-drx-cycle-greater-than-60-seconds-on-nrf9151-dk/473948"]From what I can see, you are using a different SIM card this time. Have you tried with the same SIM card as you used last time?[/quote]

Yes, we are using 1NCE sim at San-Francisco, USA location for testing the NRF9161. The previous test on the NRF9161 was done in India on a local NB-IoT operator's network.

Thanks!

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

Didrik Rokhaug — Fri, 15 Mar 2024 08:57:40 GMT

According to the EF-AD, this SIM card does not support deactivation in eDRX.

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

Didrik Rokhaug — Thu, 14 Mar 2024 16:04:05 GMT

Thanks, I'll have the modem team look at the trace.

From what I can see, you are using a different SIM card this time. Have you tried with the same SIM card as you used last time?

The nRF9151 and nRF9161 runs the same modem FW, so the behaviour should be the same between the two.

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

mnjLC — Thu, 14 Mar 2024 01:29:36 GMT

Hi,

Attached is the PPK trace and the modem trace that you requested.devzone.nordicsemi.com/.../nrf9151_5F00_eDRX_5F00_120_5F00_PTW_5F00_1_5F00_ATT_5F00_NoShutoff.mtrace

devzone.nordicsemi.com/.../nrf9151_5F00_eDRX_5F00_120_5F00_PTW_5F00_1_5F00_ATT_5F00_NoShutoff.ppk

Please review and let us know your findings.
Thanks!

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

mnjLC — Wed, 13 Mar 2024 10:43:06 GMT

Hi,

We are unable to collect trace as requested. As the application FW that we have seem to have the trace collection disable. Can you provide me with a Serial LTE modem application with trace enabled?

RE: SIM shutdown does not happen during the e-DRX cycle greater than 60 seconds on NRF9151 DK

Didrik Rokhaug — Mon, 11 Mar 2024 14:34:57 GMT

Hi,

Can you take a modem trace, so that we can see the communication between the SIM card and the modem?

Are you using the same SIM card as in the previous ticket?

Best regards,

Didrik