Bluetooth is a WPAN (Wireless Personal Area Network) commmunications protocol designed by the Bluetooth SIG(Special Interest Group). It replaces clables connecting many different types of devices like mobile phones and headsets, heart monitors & medical equipment.

A2DP(Advanced Audio Distribution Profile) – it enables wireless transmission of stereo audio from an A2DP smartphone (or computer) to A@DP headphones ( or stereo system).

aptX – supports wireless real-time streaming of high quality stereo audio over the Bluetooth A2DP. It includes proprietary audio codec compression algorithms. It is used in various consumer and automotive wireless audio applications.

Enhanced Data Rate(EDR) – introduced in Bluetooth v2.0 to support faster data transfer. It supports a data rate up to 3Mbps. Using reduced duty cucle control, EDR can provide lower power consumption.

Bluetooth High Speed (HS) – was released in April 2009 (in Bluetooth version 3.0+HS). It provides data transfer speeds of up to 24Mbps, though not over the Bluetooth link itself. Bluetooth link is used for negotiation and establishedment,  and the high data rate traffic is carried over a colocated 802.11 link. +HS part of the specification is not mandatory in Bluetooth version 3.0. Only devices that displays the “+HS” logo actually support Bluetooth over 802.11 high-speed data transfer.

bluetooth evolution

bluetooth evolution 2

Bluetooth 4.0 – called Bluetooth Smart was adopted in June 2010. It includes Former Bluetooth standards and BLE(Bluetooth Low energy).

BLE(Bluetooth Low energy) – defines several profiles on how a device can consume very low energy consumption while servicing a particular application. It provides reduced power consumption and cost while maintaining a similar communication range. A manufacturer can implement customize specifications for their product. A device can have multiple BLE profiles like health care profiles, sports and fitness profiles, IPSP(internet protocol support profile), ESP(environmental sensing profile) and so on.

Bluetooth Beacons – devices transmit a unique ID number that can be read by a bluetooth receiver, which can be used by an applicatoin  on ones smartphone. Bluetooth beacons are now commonly deployed as small devices(many are battery powered) that broadcasts signals through BLE technology using Bluetooth low energy antenna. Smartphone Apps identify the location of the Beacon device and activate location specific information on the smartphone. Beacons are used in many location based applications, advertisement & coupon distribution, home automation systems, transportation systems, sport stadiums, stores etc.

Bluetooth 4.1 – specification 4.1 was adopted in December 2013. Incremental software update to Bluetooth Specificaiton v4.0(no hardware updates). Increased co-existence support for LTE, bulk data exchange rate support, device multiple role simultaneous support.