PDCP Security Key Generation for Dual Connectivity

The patent segments the security key management by creating separate security keys for macro cell base stations and small cell base stations. The master key is divided into a first security key for macro cells and a second security key for small cells, allowing independent security management for each cell type while maintaining dual connectivity for high data transmission rates.

The patent performs preliminary action by pre-generating multiple security keys (first security key for macro cells, second security key for small cells) before handover occurs. The mobility management entity stores these keys in advance, so when handover to a small cell is needed, the terminal can immediately use the pre-prepared second security key without additional key exchange signaling, thus reducing control overhead while maintaining separate security management.

The patent applies preliminary action by pre-configuring the terminal with the second security key for small cell base stations before handover. When handover occurs, the terminal can immediately establish secure connection without waiting for key exchange procedures, significantly reducing latency and enabling frequent handovers while maintaining network flexibility.

The patent introduces the mobility management entity as an intermediary that centrally manages security keys for all small cell base stations. Instead of requiring physical access to each scattered small cell for security maintenance, the mobility management entity can remotely manage and update the second security keys for all small cells, making security maintenance easy despite the dispersed locations of small cell base stations.