Startup Aura Has New Twist On Personal Networking

Aura Semiconductor is heading for a collision with Bluetooth, and its chief executive knows it.

Aura Semiconductor is heading for a collision with Bluetooth, and its chief executive knows it.

Aura, a startup with offices in Wilmington, Mass., and Hong Kong, manufactures devices based on magnetic-resonance technology, a short-range, high-speed communications technique. Aura is trying to promote its technology as a competitor to Bluetooth, but it wont be easy.

Auras advantage is that Bluetooth has been abysmally slow to develop. At a December Bluetooth conference, Mike McCamon, the executive director of the Bluetooth Special Interest Group, said that "next year will be a really exciting year for Bluetooth," a mantra industry executives have recited for the past four years or so.

The first LibertyLink chips should enter production in May, Kokinakis said. Auras investors include the venture capital arm of Motorola.

"Bluetooth—thats the one were right up against," said Kenneth "Kip" Kokinakis, who was appointed chief executive in January. Kokinakis served as the former chief executive of Aureal Semiconductor, which popularized 3D sound in the PC during the late 1990s.

Auras argument is that its technology provides quality-of-service for voice and other high-priority data transmission, and that its limited range and other features provide a secure environment. Instead of RF signals, the Aura chip, called LibertyLink, propagates a short range, low-power magnetic field.

Auras technology can transmit about 350 Kbits per second, enough bandwidth for .WAV files or other high-quality audio formats, Kokinakis said. Quality-of-service issues are handled by a 16-bit rolling code encryption. The IEEE 802.15.4-compatible technology also switches rapidly among up to four channels, although the LibertyLink chip will probably ship with only two channels enabled, Kokinakis said.

The field strength between the transmitter and receiver is inversely proportional to the cube of the distance between them. By doubling ones distance from the base unit, the signal power drops by a factor of 64, making the technology unfeasible beyond three meters.

Aura showed off a design for a cellular headset at Januarys Consumer Electronics Show in Las Vegas. Aura will make only the chip, however; OEMs, such as a firm called Reason, will manufacture the end products.

One performance limitation: The magnetic antenna can only receive information if it is roughly on the same plane. To compensate, Aura needed to add three antennae, each on a different plane, and software that can switch rapidly back and forth to compensate for fluctuations in the signal.

Another possible obstacle to its adoption is the effect of magnetic fields on pacemakers, well within the range of the magnetic signal. In a safety manual used by the Department of Energys Jefferson Lab in Newport News, Virginia, the agency warns that even weak magnetic fields may interfere with the reed switches used in pacemakers.

"Cardiac pacemakers use magnetically activated reed switches to alter their operating mode," the manual states. "Normally, pacemakers sense and amplify the hearts natural pacing signal. In the alternate safety backup mode pulses are sent out at a fixed rate. The magnetic switch is provided to allow testing of the backup mode by holding a permanent magnet to the persons chest. In seriously ill individuals, the fixed frequency signal could destructively compete with the hearts natural pacing signal."

Kokinakis did not have an immediate response to inquiries about possible medical concerns.

Read our earlier article from CES which includes a discussion of Auras magnetic technology.