Method of software download with session mobility support in mobile communication systems

A with different races access technology (heterogeneous accesstechnologies) method based on Internet protocol a mobile communication system Central Africa real-time downloads software based on session starting protocol. A when the downloading software session at the same time is between different access technology for downloading recovery of the ACK/NAK first and second access network, and associated SIP user agent and when detecting with a switching terminal is cut, wherein session's condition in without release for is arranged with a apparatus for downloading session's SIP agency server transmission transmission request message, wherein the server is the inner managing a request the novel session the control of agency server, terminal key the operation in turn is provided with a new session the user agent the novel position; moreover from the finally packet for receivingA lower to machine download.