How does China Unicom check the phone bill and traffic by SMS?

Telephone bill inquiry: SMS inquiry: send "current month's telephone bill" or 10/to 100 10 to inquire about the real-time telephone bill, and send "account balance" or 102 to10 to inquire about the account balance. Thank you for your interest in Unicom's business!

Check traffic: SMS query: send "Mobile Internet traffic query" or 107 1 to 100 10 to check traffic usage (not available for 2G users). Thank you for your interest in Unicom's business!