SYSTEM AND METHOD OF OPERATION FOR CORRECTLY ROUTING LOCATION UPDATE SERVICE MESSAGES IN A CELLULAR DIGITAL PACKET DATA SYSTEM

摘要

A method of updating mobility information for a Mobile End System (MES) in a Cellular Digital Packet Data network uniquely identifies a Serving Mobile Data I ntermediate System (MDIS) in a ReDirect Request (RDR) so that the Location Update Service (L US) can complete its location updating operations. Upon attachment of the MES to the Ser ving MDIS, a RDR is created that includes a LUS address of the Serving MDIS and a Forwarding Service address (FSA) of the Serving MDIS. The RDR is then transmitted to a Home MDIS corresponding to the MES via a network backbone. The Forwarding Service address of the MES is then updated to the Forwarding Service address of the Serving MDIS. Then, the Home MDIS creates an RDC that includes as a destination address the LUS address of th e Serving MDIS and transmits to the RDC to the Serving MDIS via the network backbone. Once the LUS operations are complete, data intended for the MES received at the Home MDIS is routed based upon the FSA of the Serving MDIS. The data is received by the Home MDIS and rout ed via a Mobile Data Base Station to the MES. In an alternate operation, the LUS address of the Serving MDIS is not appended to the RDR by the Serving MDIS but is be appended to the RD R by an Intermediate MDIS should the RDR be routed to the Home MDIS by way of an interme diate MDIS. When the Intermediate MDIS receives the RDR, it determines that it is not the Home MDIS and appends the LUS address to the RDR. The Intermediate MDIS then transmit s the RDR to the Home MDIS.