There has been little publicity about the rollout of Bluetooth low energy wireless technology (formerly ultra low power Bluetooth) since the hype surrounding the merger of Nokia’s Wibree Alliance with the Bluetooth SIG back in June 2007.
Yet behind the scenes, dedicated engineering groups (including engineers from my own company, Nordic Semiconductor) are working tirelessly to finalise the specification (for public release in mid-2009), RF silicon and software of the first stand-alone Bluetooth low energy chips capable of running on coin cell batteries. Bluetooth low energy chips will be available in the last quarter of next year according to the Bluetooth SIG’s official timescales.
Standalone Bluetooth low energy chips will be expected to run for many months on AA or AAA cells in human interface device (HID) applications and for years on standard coin-cells (for example, CR2032, 3 V lithium devices) in sensor applications. The chips will do this by entering ultra-low power (ULP) idle and sleep modes for long periods then waking up rapidly to send and receive data in short communication bursts before going back to sleep1.
Such devices will feature a simplified protocol stack providing ULP idle mode operation, simple device discovery and reliable point-to-multipoint data transfer with advanced power-save and encryption functionalities.
In contrast, dual-mode Bluetooth low energy chips are likely to be employed in products like cellphones that have far more powerful battery sources (for example, lithium-ion cells). Larger capacity batteries allow handsets to enjoy Bluetooth low energy compatibility – using modified ‘classic’ Bluetooth chips – without the strict power constraints that characterise products using standalone chips.
Even as standalone and dual-mode chips are being developed, engineers are already working on the first applications (of which there will be many). After all, by eliminating the power constraints that restricted the applications of classic Bluetooth wireless technology, it’s hard to think of a wired or even wireless portable device on the market today that wouldn’t benefit from Bluetooth low energy. Bluetooth low energy will eliminate the wires in products that currently use a wired link, and for existing wireless products, swapping to the low energy technology will dramatically boost battery lifetimes.
And, in a major catalyst for the technology’s uptake, the Bluetooth SIG’s recent announcement that in addition to being power and cost optimized for sport, wellbeing and HID product categories, the Bluetooth low energy stack will also be optimized for meet the requirements of the consumer products industry for interoperable, universal remote controls.
According to the SIG’s executive director, Mike Foley, PhD, remote controls were identified as one of the key markets in the early days of Bluetooth low energy wireless technology. Foley went on to say that by bringing the experience of the Bluetooth community to bear on a low cost, interoperable solution, the SIG hoped to eliminate the common frustration of having a pile of different, incompatible remote controls sitting in living rooms around the world.