The Bluetooth Special Interest Group (SIG) rolled out the Bluetooth Core Specification Version 5.3 in July 2021. This new version brings a handful of feature enhancements, including: - Connection Subrating: This feature provides an improved method of managing the rate of data transmission between devices, making the connection more efficient. - Periodic Advertisement Interval: This enhancement allows for more frequent and regular advertising intervals, increasing the visibility and discoverability of Bluetooth devices. - Channel Classification Enhancement: This improvement allows for more precise classification of channels, improving the quality of connections and reducing interference. - Encryption Key Size Control Enhancements: This feature allows for better control over the size of encryption keys, thereby improving the security of Bluetooth connections. The Alternate MAC and PHY (AMP) Extension was removed in this release.