Method and system for messaging across cellular networks and a public data network

A method for performing a instant communication message in wireless and a environment method, system and computer program product. A message output end of a mobile device unit via wireless communication network. The information comprises a destination address, a mobile device device with users information, a content and information address. To instant messaging system formerly for mobile device unit information of user memory, a destination address with an instant message service associated, and is formed by a instant message operation of with other; and instant message service made of by including a message content the information executing in instant messaging system. To instant messaging system formerly for mobile device unit information of user memory, a destination address with an instant messaging server by, and according to a message for creating instant message, point instant message and associated user. A with a known partner through the mobile device for transmitting device or a receiving instant message, a instant message by using is a single-pole routing telephone number marks the instant message to realize optimization to the movable device device and partner combination, wherein state of layer in a mobile device unit the address and instant message routing server.