Method of transmission from TCP/IP communication network to mobile communication network and transmission and reception system therefor

The TCP/IP mobile communication network transmission and reception system for conducting transmission from a TCP/IP communication network to a mobile communication network includes a provider access server for the connection of a TCP/IP communication network to receive an IP packet in which an IP address of a mobile communication terminal as a destination of transmission from the TCP/IP communication network is stored at a header, and a mobile communication switching system for extracting an IP address from a header of an IP packet sent from the provider access server and searching for a user's telephone number corresponding to the IP address to send an originating signal and a selection signal based on the searched user's telephone number to a mobile communication network on the side of said mobile communication terminal.