The Bluetooth Special Interest Group (SIG) has confirmed the adoption of Bluetooth low energy wireless technology in the Bluetooth Core Specification version 4.0.
The hope is that this will open new markets for the wireless communications technology in devices requiring low cost and low power. These could include medical monitors, sports and security devices.
According to Michael Foley, Ph.D., executive director, Bluetooth SIG: “Bluetooth low energy modules for all sorts of new products may now be qualified – this is an important step towards our goal of enabling new markets with Bluetooth wireless technology. For example, the Continua Health Alliance has already selected Bluetooth low energy technology as a transport for the next version of its guidelines.”
This enhancement to the Bluetooth Core Specification allows two types of implementation, dual-mode and single-mode. In a dual-mode implementation, Bluetooth low energy functionality is integrated into an existing Classic Bluetooth controller.
The resulting architecture shares much of Classic Bluetooth technology’s existing radio and functionality resulting in a minimal cost increase compared to Classic Bluetooth technology. Additionally, manufacturers can use current Bluetooth technology (Bluetooth V2.1 + EDR or Bluetooth V3.0 + HS) chips with the low energy stack.
Technical Details
* Data Transfers – Bluetooth low energy technology supports very short data packets (8 octet minimum up to 27 octets maximum) that are transferred at 1 Mbps. All connections use advanced sniff-subrating to achieve ultra low duty cycles.
* Frequency Hopping – Bluetooth low energy technology uses the adaptive frequency hopping common to all versions of Bluetooth technology to minimize interference from other technologies in the 2.4GHz ISM Band. Efficient multi-path benefits increase the link budgets and range.
* Host Control – Bluetooth low energy technology places a significant amount of intelligence in the controller, which allows the host to sleep for longer periods of time and be woken up by the controller only when the host needs to perform some action. This allows for the greatest current savings since the host is assumed to consume more power than the controller.
* Latency – Bluetooth low energy technology can support connection setup and data transfer as low as 3ms, allowing an application to form a connection and then transfer authenticated data in few milliseconds for a short communication burst before quickly tearing down the connection.
* Range – Increased modulation index provides a possible range for Bluetooth low energy technology of over 100 metres.
* Robustness – Bluetooth low energy technology uses a strong 24 bit CRC on all packets ensuring the maximum robustness against interference.
* Strong Security – Full AES-128 encryption using CCM to provide strong encryption and authentication of data packets.
* Topology – Bluetooth low energy technology uses a 32 bit access address on every packet for each slave, allowing billions of devices to be connected. The technology is optimized for one-to-one connections while allowing one-to-many connections using a star topology. With the use of quick connections and disconnections, data can move in a mesh-like topology without the complexities of maintaining a mesh network