Ultra-low power is being added to the features of short-range Bluetooth technology.

The ultra low-power Wibree technology developed by Nokia will become part of the Bluetooth specification under an agreement reached by the Wibree Forum and the Bluetooth Special Interest Group (SIG), the Finnish mobile phone maker said Tuesday.

Bluetooth has been used mostly to connect larger devices such as headsets, keyboards and mice to stereos and PCs and with the help of Wibree, the technology will be able to connect much smaller button-cell battery-powered devices, like watches or sensors attached to a user's body. Wibree uses the same 2.4GHz frequency as Bluetooth.

"We look at this as an addition to the Bluetooth family of specifications, enabling a new class of devices that Bluetooth isn't really suitable for today," said Michael Foley, executive director of Bluetooth SIG.

In October 2006, Nokia's research arm announced the development of Wibree and establishment of an industry forum, including Broadcom Corp. and STMicroelectronics NV, to define a specification.

But after forming, the companies - many of them members of Bluetooth SIG - favoured having ultra low-power devices supported in Bluetooth, according to Harri Tulimaa, head of Nokia Technology Out-Licensing. "They didn't want to complete an entirely new technology," he said.

The goal is to develop specifications for two types of ultra low-cost implementations: a single-mode implementation for watches, sensors and other tiny devices to communicate with each other; and a dual-mode implementation to communicate with both single-mode and traditional Bluetooth devices.

The core specification for ultra low-power technology is already well advanced, according to Tulimaa. "We've started prototype interoperability testing between three companies and have transmitted packets over the air."

Ultra low-power Bluetooth will have a range up to 10 meters, similar to the Bluetooth Class 2 specification, which requires more energy. A button-cell battery powered device, equipped with ultra low-power Bluetooth technology, will be designed to have an average operating life of one year, according to Tulimaa. It can transmit data at a speed up to 1M bps (bit per second).

High-power Bluetooth Class 3 has a range up to 100 meters.

Foley doesn't view low-power Bluetooth as a competitor to Near Field Communications (NFC), another short-range wireless technology. NFC is designed primarily to help people make contactless transactions, he said.