Arduino simbank - how to read multiple sim cards?

Question

Arduino

There is a task to make a mini SIM bank from several SIM cards, for example, 10 pieces connected to arduino. Tell me
how to assemble this beast? It is necessary that the arduino turns on, after that it goes through all the sim cards in turn and reads new SMS messages from them.

Answer 1

Take 10 connectors for a SIM, a GSM modem, parallel all connectors and a modem according to data, supply power to each SIM separately from the controller.
Next, turn on the firmware with the firmware and power on the first sim, read SMS, turn off the modem, switch the power to the second sim ... and so on in a circle.

Answer 2

Given the specifics of the architecture, I would make a modular solution. One MK for each SIM card, and a separate MK for dispatching.
This MK is in the form of Nano Pro, which is very cheap and takes up little space.