I am using a GSM/LTE module (EC21 Quectel) to send and recieve sms with HyperTerminal application on computer by at-commands. I can send sms to devices with the same operator (intra-operator), but not to any other operator (inter-operator). I can even recieve sms from other operators on my module, but when i try sending to them i get error.
so does anybody know how to send an inter-operator sms? i would really appreciate it if anyone could help.