AMSTERDAM, the Netherlands — In the midst of a critical industry debate over the future evolution of the wireless technology, the Bluetooth Special Interest Group presented details of its soon-to-be-ratified Version 1.2 specification at Bluetooth World Congress here.
The group also disclosed details of its discussions about the emerging medium- and high-rate Bluetooth plans.
Both silicon vendors and OEMs back Version 1.2, although the industry appears sharply divided over the Bluetooth roadmap beyond the new spec. Some semiconductor companies in particular are debating the timing of the Bluetooth medium-rate spec release. The reason is they are barely ready with engineering samples of Version 1.2 spec-compliant Bluetooth chips.
Also, many in the industry remain skeptical of the development efforts for Bluetooth high-rate, which still under development.
The Version 1.2 spec is "on track for adoption in September," according to Jennifer Bray, a member of Bluetooth architecture review board.
The spec, based on an advanced frequency hopping scheme, promises critical performance improvements for existing Bluetooth application scenarios. Designed for quick deployment, it offers improved coexistence with 802.11 systems, enhanced voice processing, faster connection set up, enhanced service quality and an anonymity mode which could increase the security of Bluetooh wireless connections by masking a radio's physical address.
Although Version 1.2 is a welcome upgrade for Bluetooth, the competitive wireless market poses serious challenges for the technology's future. The success of other wireless standards such as WiFi and the emergence of rival technologies such as ultra-wideband, have spawned doubts about Bluetooth's future.
Nonetheless, the Bluetooth community is readying the Bluetooth medium rate specification, designed to increase the data rate from the current 1Megabit per second (Mbps) to 2 to 3 Mbps. The new spec maintains backward compatibility with basic-rate Bluetooth, but requires a new RF modulation/demodulation scheme.
Although chip companies such as Broadcom and Texas Instruments will not introduce medium-rate Bluetooth silicon until 2005, many consumer OEMs are said to be pushing medium-rate technology for popular multimedia applications like faster digital image transfers, stereo-quality audio streaming and video streaming.
"As consumers' application needs grow, the technology needs to evolve," said Maria Khorsand, president of Ericsson Technology Licensing.
By contrast, Bluetooth high-rate development is far from complete, and is far more controversial. The high-rate group, which released its Version 0.5 spec last year, was opened to Bluetooth SIG members late last year. The Bluetooth high-rate spec requires both a new radio and a new media access controller (MAC) in order to increase Bluetooth functionality and expand date rates up to 12 Mbps.
Proponents of the high-rate spec said it is not intended to compete with wireless LAN. "This is still a short range technology, designed for personal area networks (PAN), using a low-power, low-cost solution," said Jaap Haartsen, chief scientist at Ericsson Technology Licensing.
Bluetooth high-rate spec features would include a ten-fold improvement in its data rate. It would also enables peer connectivity without requiring intervention by a master, while offering low latency, flexible quality of service mechanisms and acknowledged broadcast and multicast support.
The Bluetooth high-rate spec uses a frequency range between 2405 and 2479 MHz, with a 1 MHz channel spacing. The high-rate spec will also use M-ary differential phase shift keying for its modulation format.
Proponents justified their decision to go with a new MAC by citing the Bluetooth community's eagerness to enable new applications that require slave-to-slave communicationѿTCP/IP support, for example—as well as audio and video content that supports multicast and enhanced service quality. The new MAC is also expected to offer enhanced performance including higher efficiency, lower latency and reduced dead time.
Ericsson's Haartsen estimated that design and cost challenges included "about 5 percent increase in its complexity for the front-end radio [and] 30 percent increase in gates in the baseband chip." Because the upcoming medium-rate Bluetooth will already use a new modulation scheme derived from this high-rate Bluetooth, changes in radio will be minimal, he said.
Still, many in the industry remain resistant to the idea of advancing the Bluetooth spec to higher rate.
Eric Klein, manager of emerging software solutions at Palm Solutions Group (Milpitas, Calif.), said the company "is not a fan of [Bluetooth] high-rate data." Klein added, "A lot of people think of WiFi as a wireless version of Ethernet, while Bluetooth is seen as a wireless USB. We think that high-rate Bluetooth will muddy the picture in the marketplace."
Ari Rauch, general manager for the short range wireless business unit at Texas Instruments, agreed. "Bluetooth high-rate is something that I am not so sure about."
TI is merging its wireless LAN and Bluetooth silicon with a proprietary algorithm and a three-wire bus that will allow simultaneous operation of both air interfaces. "A combined chip that offers both Bluetooth and a limited bandwidth version of WirelessLAN" could easily meet consumer demand for higher data rate applications, Rauch said. The company will unveil such a chip this fall.
