Notes

The Bluetooth Core Specification version 4.0, adopted as of 30 June 2010, includes:
begin{enumerate}
item Classic Bluetooth (legacy Bluetooth protocols)
item Bluetooth high speed: It is based on WiFi. Following are the main features of Bluetooth high speed:
begin{enumerate}
item Uses high-speed radio only when needed, thus reducing power consumption. This results in longer battery life for devices.
item The Generic Alternate MAC/PHY lets the radio discover other high-speed devices only when they are needed to transfer data.
item Makes power control faster and ensures limited drop-outs, making it less likely for consumers to lose a headset connection.
item Consumer experience is improved since Unicast Connectionless Data lowers the latency rates. It sends small amounts of data more quickly.
end{enumerate}
item Bluetooth low energy: It was previously known as Wibree. Bluetooth low energy is a subset of Bluetooth v4.0 with a new protocol stack for rapid build-up of simple links. It provides an alternative to the Bluetooth standard protocols introduced in Bluetooth v1.0 to v3.0. It is designed for very low power applications running off a coin cell. Chip designs allow for two types of implementation:
begin{enumerate}
item Single-mode implementation: only the low energy protocol stack is implemented. STMicroelectronics,[64] AMICCOM, CSR, Nordic Semiconductor and Texas Instruments have released single mode Bluetooth low energy solutions. Cost-reduced single-mode chips feature a lightweight Link Layer providing ultra-low power idle mode operation, reliable point-to-multipoint data transfer with advanced power-save, simple device discovery, and secure encrypted connections at the lowest possible cost. They also enable highly integrated and compact devices.
item Dual-mode implementation: Bluetooth Smart functionality is integrated into an existing Classic Bluetooth controller. As of March 2011, Qualcomm-Atheros, CSR, Broadcom and Texas Instruments have announced the availability of chips meeting the standard. The compliant architecture shares all of Classic Bluetooth’s existing radio and functionality resulting in a negligible cost increase compared to Classic Bluetooth.
end{enumerate}
end{enumerate}
The provisional names for Bluetooth version 4.0 i.e. Wibree and Bluetooth ULP (Ultra Low Power) were abandoned and the BLE name was used. As the general-public face of BLE, new logos “Bluetooth Smart Ready” for hosts and “Bluetooth Smart” for sensors were introduced in late 2011.

Some other improvements included in version 4.0 are the changes necessary to facilitate BLE modes, as well the Generic Attribute Profile (GATT), Security Manager (SM) services with AES Encryption, improvements to the audio Host Controller Interface and to the High Speed (802.11) Protocol Adaptation Layer.