Are there 3g/4g sim modems for two sim cards for roaming?

Question

Telephony

We need a 3g / 4g modem on 2 sim cards, which, when one sim goes into roaming, would switch to the second one (or with a stronger signal of the second sim). One sim within the country, the second for roaming. Switching should occur exactly programmatically, not manually. Is it possible to somehow implement this myself, if there are no such modems (and I have not found such yet :)). We are talking about a modem, not a wifi router.

Answer 1

unless
you can get the roaming status from the operator with the TV, then it's up to the encoders

Answer 2

Jinga A500 LTE with dual SIM and support, support for memory cards, LCD screen, support for sms and calls

Answer 3

Yes, but without "roaming" recognition. The easiest way is to stupidly prohibit Data Roaming on one of the maps (which is for the country) (for MegaFon, for example, it becomes an elementary tick). And in the modem, the condition for switching to another card "complete loss of communication from the 1st card within n seconds" is configured.
www.gearbest.com/wireless-routers/pp_598375.html
www.3grouterstore.co.uk/3G/Dual-SIM-4G-Router.html

Answer 4

There is just CwSim without roaming, which can be installed in a modem and distribute the Internet. Here, how to do it and with which routers the card works. About the card itself without roaming.