METHOD, APPARATUS AND COMPUTER READABLE MEDIUM FOR HFN HANDLING AT INTER-BASE STATION HANDOVER IN MOBILE COMMUNICATION NETWORKS

摘要

Systems and methods for addressing the de-synchronization of the cryptosync between the network and the mobile stations (eNB) that can occur at mobility are addressed. De-synchronization is resolved by forwarding HFN and PDCP Sequence Number(s) from the source eNB to the target eNB. In order to avoid re-use of a cryptosync for a given key, a backward offset from the initial COUNT value is used by the target eNB. These approaches do not require an over-the-air signaling and the COUNT value handling in the network is transparent to the mobile station.