There are two Bluetooth technology systems: Basic Rate (BR) and Low Energy (LE).
Both systems include device search, connection establishment, and connection management.
The Basic Rate (BR) technology system provides synchronous and asynchronous connections for the following 3 technologies: * Basic Rate
with a data transfer rate of 721.2 kb/s * Enhanced Data Rate with a data transfer rate of 2.1 Mb/s * Data transfer rate of 54 802.11 AMP at Mb/s
Compared with the BR technology, the Low Energy (LE) technology system has the characteristics of low power consumption, low complexity, low cost, and low speed.
A device that implements two technology systems can communicate with a device that implements both technology systems, or it can communicate with a device that implements only one of the two technology systems.
However, a device that implements only one technology system cannot communicate with a device that only implements another technology system.
Some specifications and usages are only supported by one of the technology systems; if a device implements both technology systems,
it can support almost all specifications and usages.
The Bluetooth Core system consists of a Host and one or more Controllers .
Host refers to the logical entity composed of various layers above HCI (Host Controller Interface) below the profiles.
Controller refers to the logical entity composed of the following layers of HCI.
Controller includes: Primary Controllers and Secondary Controllers.
The Bluetooth core that only implements the main controller has the following 3 configurations:
* BR/EDR Controller, including: Radio, Baseband, Link Manager and optionally HCI
* LE Controller, including: LE PHY, Link Layer and optionally HCI
* Integrated BR/EDR Controller and LE Controller into one controller, and share the MAC address.
The Bluetooth core including the primary controller and secondary controller is:
* an Alternate MAC/PHY (AMP) Controller including an 802.11 PAL (Protocol Adaptation Layer), 802.11 MAC and PHY, and optionally HCI.
For more content reference: Bluetooth learning summary