METHOD, USER EQUIPMENT AND COMMUNICATION SYSTEM FOR INTER-RAT HANDOVER IN 3G LTE

摘要

The invention provides a method for enabling inter-RAT handover in a communication system comprising a first network utilizing a first radio access technology and a second network utilizing a second radio access technology. When a user equipment moves from the first network into the second network and a handover is to be made, processing protocol data units (PDUs) in non-IP packet format and buffered in the first network or in the user equipment into IP packets in response to a handover confirmation (HOcfm) sent by the second network; forwarding the processed IP packets from the first network to the second network if the PDUs are buffered in the first network; and retransmitting the processed IP packets after the user equipment is switched to the second network. An user equipment and a communication system corresponding with the method of the invention are also provided.