Bluetooth 4.0 To Add Low Energy Spec, Enable New Wave Of Devices

Bluetooth 3.0 just got official in the Spring, and already we're hearing about Bluetooth 4.0. So much for the latest and greatest staying the latest and greatest, huh? The Bluetooth Special Interest Group (SIG) today announced the adoption of Bluetooth low energy wireless technology, which is the hallmark feature of the Bluetooth Core Specification Version 4.0. Of course, we already knew that a low energy spec of the protocol was on the way, but instead of being integrated into 3.0, it seems as if it won't be utilized until 4.0.

BT low energy has been a long time coming, and it's badly needed for lots of devices to really take advantage of short-range wireless communications. Some smaller devices have been missing out on Bluetooth, particularly ones that don't posses huge batteries to begin with. The Bluetooth SIG suggests that industries like healthcare, sports/fitness, security and home entertainment will be enhanced, and given that this spec will enable BT to be powered in coin-cell battery powered wireless products, we can't disagree with that gesture.

Some of the product highlights and technical details are pasted below. Bluetooth is really setting itself up to be the go-to wireless standard for device-to-device communication. BT 3.0 adds high-speed options, and if 4.0 brings low energy, it's pretty much the whole package. Hopefully we'll see a new influx of wireless headphones, media players and the like in the near future.


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 classic Bluetooth (Bluetooth V2.1 + EDR or Bluetooth V3.0 + HS) chips with the new low energy stack, enhancing the development of classic Bluetooth devices with new capabilities.

Technical Details

  • Data Transfers Bluetooth low energy 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 uses the adaptive frequency hopping common to all versions of Bluetooth technology to minimize interference from other technologies in the 2.4 GHz ISM Band. Efficient multi-path benefits increase the link budgets and range.
  • Host Control Bluetooth low energy 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 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 of over 100 meters.
  • RobustnessBluetooth low energy 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 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.