How to cancel the SMS center number

The error of signal is an important reason for not sending information. You just need to change the central code to the original one. If you forget the center number, you can show your friend the center number of his mobile phone. Almost all the center numbers in this city are the same. One version of smart phone is to enter SMS first, and then enter SMS settings. Then set the SMS mode. What are the modes of one mode, two modes and three modes? You can enter one at will and change the center number to be OK. For the record, it is impossible for the landlord to cancel the signal, otherwise the messages you send will be free. It just says that it has been changed, but generally, after changing the center number, you can't send a message. That's why.