RAPID HANDOVER OF A MOBILE STATION BETWEEN RADIO NETWORK CONTROLLERS ACCESSING AN ENHANCED GENERAL PACKET RADIO SERVICE (EGPRS) NETWORK

摘要

A RATIO ACCESS NETWORK (RAN) AND METHOD FOR RAPID HANDOVER OF A MOBILE STATION BETWEEN A SOURCE RADIO NETWORK CONTROLLER (SRNC) AND A TARGET RADIO NETWORK CONTROLLER (TRNC) IN THE RAN. A MOBILE STATION INITIALLY SERVED BY THE SRNC ACCESSES AN ENHANCED GENERAL PACKET RADIO SERVICE (EGPRS) NETWORK THROUGH THE RAN FOR CONDUCTING A PACKET-SWITCHED CALL. WHEN HANDOVER TO THE TRNC IS REQUIRED, THE SRNC NOTIFIES THE TRNC THAT RELOCATION OF THE MOBILE STATION TO THE TRNC IS REQUESTED. THE TRNC RESERVES RADIO RESOURCES REQUIRED TO SERVE THE MOBILE STATION IN THE TRNC, AND NOTIFIES THE SRNC THAT RELOCATION IS APPROVED. AN IUX INTERFACE MAY BE ESTABLISHED BETWEEN THE SRNC AND THE TRNC FOR DIRECT COMMUNICATION OF CONTROL SIGNALING. ALTERNATIVELY, THE CONTROL SIGNALING BETWEEN THE SRNC AND THE TRNC MAY PASS THROUGH THE EGPRS NETWORK. THE EGPRS BEGINS BI-CASTING PACKET DATA UNITS (PDUs) TO BOTH THE SRNC AND THE TRNC UNTIL NOTIFIED BY THE TRNC THAT THE HANDOVER IS COMPLETE. THE MOBILE STATION IS THEN HANDED OVER TO THE TRNC, AND THE EGPRS NETWORK IS NOTIFIED BY THE TRNC THAT TH HANDOVER IS COMPLETE. WITH THE IUX INTERFACE, CONTROL SIGNALING THAT IS SPECIFIC TO THE RAN DOES NOT HAVE TO BE PASSED THROUGH THE EGPRS NETWORK.FIGURE 3