Abstract
The present invention provides a roaming system in a heterogeneous wireless network environment, which comprises a server, a host, a registration table, and a dynamic link layer; wherein, the registration table could be registered by the server with the dynamic address and updating the dynamic address; the host could query from the registration table for the newest dynamic address; and, the server and the host could establish the dynamic link through the dynamic link layer for data exchange, and employing the buffer units and pointers located at both ends of the dynamic link to record the transmitted data and confirm the received data; and, when the link is disconnected, it could re-establish the link according to the newest dynamic address on the server, and using the pointer position to check the records on the buffer area, so as to check if there is some missing data needed to be resent.