How to send a short message from a base station?

SMS sending method of base station: When the mobile phone is turned on, it will automatically send a notification to the surrounding base stations. After receiving it, the surrounding base stations will be allowed to access the network, and at the same time upload the location of the base stations to the WAN, so as to record which base station area the users are in. When there is a phone call for you, find the user from the recorded base station according to the recorded information, and then the base station will find the user's terminal, and that's all.