METHODS AND SYSTEMS FOR HFN HANDLING AT INTER-BASE STATION HANDOVER IN MOBILE COMMUNICATION NETWORKS

摘要

Systems and methods for addressing thede-synchronization of the cryptsync between the networkand the mobile stations (eNB) that can occur at mobilityare addressed. De-synchronization is resolved by forwardingHFN and PDCP Sequence Number(s) from thesource eNB to the target eNB. In order to avoid re-use ofa crytosync for a given key, a backward offset from theinitial COUNT value is used by the target eNB. These approachesdo not require an over-the-air signaling and theCOUNT value handling in the network is transparent tothe mobile station.