SAN JOSE, Calif. " OEMs and vendors are gearing up to deliver wireless headsets that support stereo audio, promising a new generation of untethered MP3 players and music-enabled cell phones. But backers are divided between using standard approaches like Bluetooth or proprietary systems, raising the potential for incompatible systems in the marketplace.
Startup Zeevo Inc. (Santa Clara, Calif.) and Cambridge Silicon Radio plc (CSR; Cambridge, England) will release competing Bluetooth products this week that support stereo sound, saying the first headsets will hit the shelves well before Christmas.
Meanwhile, Aura Communications Technology Inc. (Wilmington, Mass.) will announce this week that it has signed up MP3 maker Creative Technology Ltd. (Singapore) as part of an $11 million investment round for its proprietary and unique modulated magnetic-field approach to short-range wireless audio. And an Apple Computer Inc. executive suggested its popular iPod, which is widely expected to make the leap into wireless, may also adopt something other than Bluetooth.
"We see an excellent growth potential in 2004 and beyond for stereo applications for Bluetooth. Bluetooth-enabled MP3 players, stereo headsets, stereo speakers and other such products should grow at a 70 percent rate in 2005 " and that may be conservative," said Joyce Putscher, principal wireless analyst for market watcher In-Stat/MDR.
Putscher said she has seen well-optimized demos for Bluetooth stereo from Zeevo and RF Micro Devices Inc., which acquired Bluetooth developer Silicon Wave Inc. in May 2003. Infineon Technologies AG also will take part in this market, she added.
"The mobile-phone manufacturers are driving this. They see music as being the next big thing in phones after embedding a camera, and carriers want to sell music download services," said Luke D'Arcy, who is product-marketing manager with CSR, which claims to hold the majority of the market for Bluetooth silicon in cell phones.
The headsets will create a new and more profitable strata of Bluetooth silicon, said Anil Aggarwal, founder and vice president of marketing for Zeevo. He estimates half of all cell phones will integrate Bluetooth by 2006 and 30 percent of all cell phones that year will have MP3 capabilities, preparing the way for a robust stereo headset market.
Taking a cooler view of the stereo market, a Philips Semiconductors manager said Bluetooth mono headsets are set to soar, in part because carriers and cell phone makers are starting to bundle the headsets with the phones rather than leave them as aftermarket products. However, he said the stereo versions will be slow to ramp and might represent less than 20 percent of all headset sales.
Pros and cons
The current 723-kbit/second rate of Bluetooth 1.2 certainly has its challenges eking out a new market in multimedia personal-area networking. While the technology is relatively low-cost, low-power and has quality-of-service capabilities, it operates in the noisy and overcrowded 2.45-GHz band, uses compressed audio and must support multiple simultaneous links with various master and slave systems.
The cracks, pops and dropouts from interference with Wi-Fi signals, microwaves and cordless phones in the 2.45-GHz band will be the main reason many people opt for proprietary solutions over Bluetooth, said Todd Antes, director of marketing and business development in the wireless unit of Philips. But D'Arcy said Bluetooth's newly added Adaptive Frequency Hopping feature will prevent interference with Wi-Fi, and a next-generation Enhanced Data Rate for Bluetooth will ease the other interference problems.
"The real issue for audiophiles is they can hear a difference when you use compressed audio. So Bluetooth isn't really suitable for this small group, but for the mass market it's good enough," Antes said.
For its part, Zeevo uses a 48-MHz ARM7 with a separate Bluetooth baseband link controller block in its ZV4301, which it is announcing this week. The 180-nanometer chip processes the entire Bluetooth stack and traffic management functions such as voice/music switching. It provides about eight hours of battery life using alkaline or lithium batteries and has a peak power consumption of about 165 milliwatts. A full bill of materials runs about $15 per link.
CSR hopes to release to manufacturing this week its BlueCore 3 Multimedia chip with roughly similar features, costs and power consumption. It uses an on-board DSP rather than an ARM. The DSP handles the subband coding required for the Bluetooth AV profile.
While Bluetooth is adapting to the rigors of stereo headset applications, it continues to fall short in terms of interference and power consumption, according to Dan Cui, vice president of sales at Aura Communications. The company plans to spend its recent injection of $11 million, from Creative Technology and others, to launch its next-generation streaming audio ASIC later this year.
Aura's approach involves generating a low-level static magnetic field around the user and modulating that using Gaussian mean-shift keying at a frequency between 10 and 15 MHz (nominally 13.56 MHz). Due to its unique magnetic-field modulation scheme, Cui said there are almost no issues with interference. Moreover, its steep roll-off creates something akin to a bubble around the user, he said, vs. an RF device that radiates in all directions; power is also kept to a minimum.
The new chip can reach rates of up to 410 kbits/s with a full-rate receive power consumption of 10 mA off a 2-volt supply, said Kip Kokinakis, president and chief executive officer of Aura. "The chip set in volume has a target price of under $5."
At Apple Computer, a manager close to the iPod team said the company has "finally found something that does what Bluetooth always claimed it would do," but declined to elaborate. Industry sources have speculated for months that the company is on the brink of rolling out a wireless version of its high-profile MP3 player.