(Posting to the OpenBSC list because I figured that the set of people who issue their own SIMs probably has a good overlap with the set of people who operate their own physical GSM networks.)
I am shopping for some non-carrier-branded, non-carrier-issued SIM cards for use in testing my FreeCalypso GSM MS devices (specifically, testing of the SIM interface in isolation without bringing up radio, as well as radio and full MS functionality testing with a base station simulator like CMU200 instead of live networks), and the only product I found so far is sysmoUSIM - if anyone else makes a similar product ("generic" SIM cards for tinkerers), I would like to know about it.
In the case of sysmo(U)SIM cards, it looks like 2FF-only cards are no longer available, and the current choices are 2FF+3FF or 2FF+4FF. My question is: if I only want 2FF and have no interest in 3FF or 4FF, which variant should I buy? In other words, which variant is mechanically stronger and less likely to break in 2FF-only usage in various kinds in 2FF sockets?
TIA, Mychaela
Hi Mychaela,
On Fri, Jul 21, 2017 at 02:47:16PM -0800, Mychaela Falconia wrote:
In the case of sysmo(U)SIM cards, it looks like 2FF-only cards are no longer available,
Yes, we had sysmoSIM-GR1 in 2FF-only form factor very early on (> 5 years ago), but the specific chip/OS was not satisfactory (GRcard), and most people were asking about smaller form-factors
and the current choices are 2FF+3FF or 2FF+4FF. My question is: if I only want 2FF and have no interest in 3FF or 4FF, which variant should I buy? In other words, which variant is mechanically stronger and less likely to break in 2FF-only usage in various kinds in 2FF sockets?
I would recommend the 2FF+3FF. You could put some strong, thin adhesive tape (like kapton used in electronics rework) on the back to avoid the frame and the 3FF part from separating.
Hello Mychaela,
On Sat, Jul 22, 2017 at 1:47 AM, Mychaela Falconia mychaela.falconia@gmail.com wrote:
the only product I found so far is sysmoUSIM - if anyone else makes a similar product ("generic" SIM cards for tinkerers), I would like to know about it. In the case of sysmo(U)SIM cards, it looks like 2FF-only cards are no longer available, and the current choices are 2FF+3FF or 2FF+4FF. My question is: if I only want 2FF and have no interest in 3FF or 4FF, which variant should I buy?
I'm curious - since you're doing your own hardware, why not install a 3FF/4FF slot instead of a 2FF? Or even install two or three of them to give users a choice? I don't think you're really limited in space on your PCB, looking at it. But even with a 2FF slot, I'm surprised you have issues with mechanical strength - 3FF/4FF SIMs work fine with 2FF slots with an "adaptor", unless you plan to insert/remove them really frequently. And then, as Harald has mentioned, a small piece of a thin tape helps a lot.
PS We're also making / selling our own Fairwaves branded SIM cards, but only to customers who buy our BTS so far and we make them 2FF/3FF/4FF by default, as that's what most people want nowadays. So that's not much of a difference from what you get from Sysmocom.
-
Alexander Chemeris -
Harald Welte -
Mychaela Falconia