Beam Selection-Based Security Key Generation for Base Station

The patent changes the parameter used for security key generation from cell identity to beam selection information. When beamforming is employed, the base station generates security keys based on beam-specific parameters (such as beam ID or beam index) rather than cell-level parameters. This allows security keys to vary with beam changes even when the serving cell remains the same, thereby maintaining security levels while enabling long-distance communication through beamforming.

The patent segments the security key generation mechanism from the cell level to the beam level. Instead of generating security keys only when the serving cell changes, the system generates separate security keys for different beams within the same cell. This segmentation allows security keys to be refreshed more frequently through beam selection changes, even when the terminal remains in the same cell, thus preventing decryption while maintaining communication stability.

The patent uses beam selection information (such as beam ID or beam index) as a copy or derivative parameter to generate security keys, rather than requiring completely new key generation mechanisms. The base station obtains beam selection information from existing beamforming procedures and uses this information to derive security keys through standard cryptographic functions. This approach improves security by incorporating beam-specific parameters while minimizing additional device complexity by reusing existing beam management infrastructure.