1.EATT-Enhanced Attribute Protocol
Bluetooth version 5.2 improves the ATT protocol(Enhanced Attribute Protocol). Eatt supports concurrent transactions, allows att packets from different applications to cross with related L2CAP packets, and allows to change the att maximum transmission unit (MTU) during connection. In general, these changes can improve and improve the user experience on the device. When there are multiple applications using the Bluetooth low power (LE) protocol stack at the same time, it can block the use of another application by temporarily reducing the use of the protocol stack by one application. This can reduce end-to-end latency for one or more applications and improve the user's response experience. In order to support eatt, a new L2CAP schema is defined. This new mode is called enhanced credit flow control model based on L2CAP. This pattern provides flow control, thus allowing applications to treat protocols as reliable. Compared with the unenhanced ATT, EATT with security advantages because it can only be used on encrypted connections.
2.LE Power Control
2.1. Reduce the total power consumption of transmitter by dynamic power management between connected devices.
2.2. Maintain the signal strength of the receiver to keep it in the best range supported by the receiver, so as to improve the reliability.
2.3. Improve co-existence with other wireless devices in the environment using the 2.4 GHz frequency range.
This feature is mainly designed to support Le audio (next generation Bluetooth audio). It allows time limited data to be transmitted to one or more devices for time synchronization. It can be used by connection or broadcast to an unlimited number of devices in a connectionless manner. However, music sharing is just an app. Le audio, based on the new Le synchronization channel, will provide a new standard for listeners and support auxiliary hearing systems in different locations such as theatre, conference, lecture hall and airport. It is expected that multilingual audio systems will become possible.