MOBILE COMMUNICATION SYSTEM AND WIRELESS BASE STATIONS

摘要

In order to avoid HFN inconsistencies between a handover destination wireless base station (eNB#2) and a mobile station (UE) in a transmission path between a handover source wireless base station and the handover destination wireless base station, even if bulk packet loss has occurred, in this mobile communication system, if a predetermined COUNT value (Y) used for processing a subsequent PDCP-SDU is greater than the sum of the oldest value (X) and a predetermined value (Z) among COUNT values used for processing a first PDCP-PDU, a wireless base station eNB#1 forwards a PDCP-SN that forms such a sum to the wireless base station eNB#2 instead of a PDCP-SN that forms the COUNT value Y, and does not forward the PDCP-SN that forms a COUNT value that is greater than or equal to said sum among the COUNT values used for processing a first PDCP-SDU and a second PDCP-SDU.