Do the SIM cards select internet technologies like GPRS, UTMS, HSDPA, EDGE? Because SIM900 module using GPRS technology can not connect internet when it is used together with newly received SIM cards.
I think the SIM card is just a memory chip which contains the network operators code using which the module can connect to the network.
The module selects which network it can connect to.
There are modules like SIM7600 which can connect to 4G LTE as well as 3G UMTS, There are commands available which can be issued to select any one of the networks available. Same as we have on our smartphones where we can select LTE/3G/2G.
I have seen the modules face problems with 64K/128K SIM cards. They seem to create problems and modules are unable to connect to network using them. I use normal SIM cards which dont have the memory written on them.
Thank you for your help.