Page 1 of 1

Dual SIM Single Standby

Posted: Wed Jan 22, 2020 11:41 am
by ltedependent
The EM7511 advertises Dual SIM Single Standby support.
But the devices that accept it only have a single SIM card slot.

thewirelesshaven suggested using the "Mini PCI-E to M.2 (NGFF) Key B Adapter with Top SIM Card Slot" and the "USB3.0 To Mini PCI-E Adapter Enclosure With SIM Card Slot" together to get two SIM slots, but it's not obvious that combination will do what the EM7511 expects.

Has anyone tried this?
How would I even tell the EM7511 to switch between them in software if it does work?

Re: Dual SIM Single Standby

Posted: Wed Jan 22, 2020 5:39 pm
by BillA
ltedependent wrote: Wed Jan 22, 2020 11:41 am The EM7511 advertises Dual SIM Single Standby support.
But the devices that accept it only have a single SIM card slot.

thewirelesshaven suggested using the "Mini PCI-E to M.2 (NGFF) Key B Adapter with Top SIM Card Slot" and the "USB3.0 To Mini PCI-E Adapter Enclosure With SIM Card Slot" together to get two SIM slots, but it's not obvious that combination will do what the EM7511 expects.

Has anyone tried this?
How would I even tell the EM7511 to switch between them in software if it does work?

Good questions.... so even if you somehow manage to get the two sim cards slots working with one modem, the router's firmware would also have to support it, to be able to switch between the two sims. I don't believe the radio can operate on both sims at the same time (to pick up signal and communicate simultaneously).

Another solution which might work, is to use a router with either two modem slots with the sim card inserted in each modem's Key B adapter, or a single slot modem router with the second modem tethered via usb in an external enclosure. This method would allow the router to not only use both services at the same time (/dev/ttyUSB<1/2>) but also do some fancy load balancing/aggregation. You're threading uncharted waters with this, so let us know how things work out. With a handle like " LTEdependent " I'm sure you'll figure it out... you'll have to! ;)

Re: Dual SIM Single Standby

Posted: Wed Jan 22, 2020 6:52 pm
by JimHelms
ltedependent wrote: Wed Jan 22, 2020 11:41 am The EM7511 advertises Dual SIM Single Standby support.
But the devices that accept it only have a single SIM card slot.

thewirelesshaven suggested using the "Mini PCI-E to M.2 (NGFF) Key B Adapter with Top SIM Card Slot" and the "USB3.0 To Mini PCI-E Adapter Enclosure With SIM Card Slot" together to get two SIM slots, but it's not obvious that combination will do what the EM7511 expects.

Has anyone tried this?
How would I even tell the EM7511 to switch between them in software if it does work?
The EM7565 for sure supports dual SIMs as they are used in some of the later MC400 modems. The EM7511 should be no different.

There is post somewhere on the forum about this topic, and the AT Commands required to place the modem in dual SIM mode. I did a quick search but could not locate it.

The switch would need to be firmware driven, and may be possible with GoldenOrb by using the profile options. I would have to think about exactly how.

Re: Dual SIM Single Standby

Posted: Thu Jan 23, 2020 8:10 pm
by ltedependent
Found this: http://wirelessjoint.com/viewtopic.php?t=98

Seems Cradlepoint makes a MC400-600M-C-AT with dual SIM support and the EM7511 inside, but locked to AT&T and double the price (in which case one could just buy two modems and use both SIMs in parallel!)

Reading the MiniPCIe-to-M.2 adapter description, I see "The adapter will ignore (i.e., not read) a SIM Card installed in a router’s SIM Card slot" which makes me doubt what The Wireless Haven told me about using it to get a 2nd SIM slot...

I don't worry about software - I can always hack that together. But it seems the hardware solution may be lacking. :(

Re: Dual SIM Single Standby

Posted: Thu Jan 23, 2020 8:34 pm
by JimHelms
ltedependent wrote: Thu Jan 23, 2020 8:10 pm

Reading the MiniPCIe-to-M.2 adapter description, I see "The adapter will ignore (i.e., not read) a SIM Card installed in a router’s SIM Card slot" which makes me doubt what The Wireless Haven told me about using it to get a 2nd SIM slot...
You are most likely referring to the wrong Mini PCI-E adapter. THIS adapter states:
This adapter is used to convert a mini PCI-E wifi slot (full or half) to use a mini PCI-E modem.

This M.2 adapter MUST USE the SIM Card slot that is available on the adapter–and is primary used to convert a mini PCI-E wifi slot (full or half) to use a mini PCI-E modem.

The adapter will ignore (i.e., not read) a SIM Card installed in a router’s SIM Card slot, while some routers may be unable to read the SIM Card slot on this adapter.
Now, compare that adapter to THIS one which states:
The extra SIM card slot is a bonus for applications where a SIM card slot is not available. Its use for a second SIM card is optional when using the adapter on routers that are already equipped with a SIM card slot. It’s use is not required.

Re: Dual SIM Single Standby

Posted: Sat Jan 25, 2020 3:20 pm
by ltedependent
JimHelms wrote: Thu Jan 23, 2020 8:34 pm You are most likely referring to the wrong Mini PCI-E adapter. THIS adapter states:

Now, compare that adapter to THIS one which states:
Wow, I thought the only difference was top/bottom! Gotta look more carefully I guess...

Has anyone tested the DSSS usage with this setup?