New low-energy standard will make Bluetooth ubiquitous

18 Dec 2009

A new ultra low-power version of Bluetooth, version 4.0, will see the spread of the wireless technology from mobile today to new markets like security, healthcare, sports and fitness, and home entertainment.

Yesterday, the Bluetooth Special Interest Group (SIG) announced the adoption of Bluetooth low-energy wireless technology, which is the hallmark feature of the Bluetooth Core Specification Version 4.0. 

They say that the low power and low cost of the technology will enable a plethora of new applications – some not even possible or imagined today.

“With today’s announcement the race is on for product designers to be the first to market,” said Michael Foley, PhD, 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 as a transport for the next version of its guidelines.”

Features of Bluetooth low-energy wireless technology

Bluetooth low-energy wireless technology, the hallmark feature of the V4.0 Bluetooth Core Specification, features: Ultra-low peak, average and idle mode power consumption, the ability to run for years on standard coin-cell batteries, low cost, multi-vendor interoperability and enhanced range

“Nokia has been committed to this ultra low-power wireless technology since its Wibree technology development,” said Markku Verkama, director, Devices R&D Nokia.

“Now we are happy to see the adoption of the Bluetooth low-energy specification, which will open up new market opportunities and space to innovate for the industry. The wide manufacturer base behind Bluetooth low-energy technology and the combined industry effort will result in exciting new user experiences in the mobile space,” Verkama said.

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.

Less cost

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.

Single-mode chips, which will enable highly integrated and compact devices, will feature a lightweight Link Layer providing ultra-low power idle mode operation, simple device discovery, and reliable point-to-multipoint data transfer with advanced power-save and secure encrypted connections at the lowest possible cost.

The Link Layer in these controllers will enable internet-connected sensors to schedule Bluetooth low-energy traffic between Bluetooth transmissions.

Features of Bluetooth low energy:

Data Transfers – Bluetooth low-energy supports 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 minimise 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 – Bluetoothlow 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 more than 100 metres.

Robustness – Bluetooth 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 optimised 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.

By John Kennedy

John Kennedy is a journalist who served as editor of Silicon Republic for 17 years