Bluetooth is a wireless connectivity options which transfers data at high speed. It is multi directional and has long range of connectivity. Bluetooth Smart is the intelligent, power-friendly version of Bluetooth wireless technology. While the power-efficiency of Bluetooth Smart makes it perfect for devices needing to run off a tiny battery for long periods, the magic of Bluetooth Smart is its ability to work with an application on the smartphone or tablet you already own. Bluetooth Smart makes it easy for developers and OEMs to create solutions that will work with the billions of Bluetooth enabled products already in the market today.
v1.0 and v1.0B
Versions 1.0 and 1.0B had many problems, and it was difficult for manufactures to make their products interoperable. These versions also included mandatory Bluetooth hardware device address transmission in the Connecting process which was a major setback for certain services planned for use in Bluetooth enviroments.
This version was ratified as IEEE Standards 802.15.1 – 2002. Many errors of Bluetooth v1.0 were fixed in this version. Possibility of non-encrypted channels was added. It also received Signal Strength Indicator (RSSI).
This version received major enhancement which include:
- Faster connection and discovery
- Adaptive frequency-hopping spread spectrum
- Higher transmission speeds, up to 721 kbps
- Extended Synchronous Connections, which improved voice quality of audio links
- Host Controller Interface (HCI) operation with three-wire UART
- Ratified as IEEE Standard 802.15.1 – 2005
- Introduced Flow Control and Retransmission Modes for L2CAP
v2.0 + EDR
This version was released win 2004. The main difference was the introduction of Enhanced Data Rate(EDR) for faster data transfer. EDR was an optional feature and therefore it was published as “Bluetooth v2.0 + EDR”
v2.1 + EDR
The main feature of this version was secure simple pairing(SSP) which improves the pairing experience for Bluetooth devices, while increasing the use and strength of security. v2.1 had various other improvements including “Extended Inquiry Response”(EIR) which provides more information during the inquiry procedure to allow better filtering of devices before connection; and sniff subrating, which reduces the power consumption in low-power mode.
v3.0 + HS
In v3.0 + HS, “HS” stands for High Speed. Theoretically this Bluetooth version provides data transfer speed of up to 24 Mbps, though not over the link itself. Other improvements in Bluetooth v3.0 were:-
- L2CAP Enhanced modes
- Alternative MAC/PHY
- Unicast Connectionless Data
- Enhanced Power Control
This version was adopted on 30 June 2010. It includes Classic Bluetooth, Bluetooth high speed and Bluetooth low energy protocols. Bluetooth High Speed is based on Wi-Fi, and Classic Bluetooth consists of legacy Bluetooth protocols. Bluetooth v4.0 transfers data at very high speed and consumes low energy. Therefore, this is mostly used in new smartphones.
The formal adoption of the Bluetooth 4.1 specification was on 4 December 2013. It is an incremental update to Specification of v4.0.l New features of v4.1 are:-
- Mobile Wireless Service Coexistence Signaling
- Train Nudging and Generalized Interlaced Scanning
- Low Duty Cycle Directed Advertising
- L2CAP Connection Oriented and Dedicated Channels
- Dual Mode and Link Layer Topology
- 802.11n PAL
- Audio Architecture Updates for Wide Band Speech
- Fast Data Advertising Interval
- Limited Discovery TIme