Bluetooth 4.0 core specification released

The earliest Bluetooth 3.0-capable devices may have only begun appearing this year, but the Bluetooth Special Interest Group is already advancing the short-range wireless standard by rolling out the core specification of version 4.0 today.

Bluetooth 3.0 introduced an Enhanced Data Rate mode which allowed higher throughput for faster file transfers between devices. Using a technique called AMP, compatible Bluetooth 3.0 radios could establish device-to-device 802.11 Wi-Fi connections for transfer speeds up to 24 Mbps. The basic rate for Bluetooth file transfers is only 721.2 Kbps.

Bluetooth 4.0 adds another layer to Bluetooth functionality and introduces low energy (LE) mode, which consumes only a fraction of the power that classic Bluetooth does, enabling a lifespan for devices comparable to active RFID. The Bluetooth Special Interest Group says devices powered by single button-cell batteries can operate for more than a year without recharging.

Low energy Bluetooth operates in the 2.4GHz ISM band, and uses a frequency-hopping transciever to avoid interference and signal degradation. It is made up of 40 physical channels, spaced 2 MHz apart. Low energy networks are formed by three different types of Bluetooth devices, ones that broadcast packets one way, ones that listen for these packets, and ones that can engage in a two-way conversation.

"The finalization of Bluetooth low energy wireless technology within the Core Specification is a monumental achievement," said Michael Foley, Ph.D., executive director, Bluetooth SIG in a statement today. "Bluetooth wireless technology can now, with the hard work of our members and our world-class qualification program, really do it all."
Interoperability testing for Bluetooth 4.0 implementations will take place at UnPlugFest 37 in Barcelona, Spain on October 4th-8th.