i am currently designing a bit critical communication system, in which we have multiple mediums of communication like GSM , VHF radio. and currently i am looking for a highly reliable GSM modem to be used in this system. for now i am thinking of Moxa , visiontek , u-blox GSM modules.
so my question is if you are in the position to chose a high reliability GSM modem then which would you chose? any suggestion?
please help
thank you