RF & MICROWAVE INTER DESIGN Honourable intentions

Bluetooth and ultrawide band are set to marry. What’s involved and who will benefit? By Graham Pitcher.

onnectivity is, of course, the latest thing. Whether it’s Cproviding new ways of access- ing information from a mobile device or finding different ways to pass data between static units, the communications industry is spawning a range of communications protocols. One reason for the growing interest in ways of passing information is due simply to the boom in digital consumer electronics products. How, for instance, can you send digital images to your pc without first having to wire it up? Simi- larly, how can that jumble of cables be removed from behind your pc? One pos- sible solution to this problem is ultraw- ide band communications, or uwb. But questions similar to those answered by uwb have been asked for some years now in the office environ- ment. When I’m on the road, for exam- ple, how can my laptop communicate with a laser printer in someone else’s office? The solution in this instance has been and its ad hoc network- Now, both technologies have decided of view is Mike Foley, executive director ing ability. Essentially, Bluetooth lets they can help each other – essentially, it’s a of the Bluetooth Special Interest Group. devices communicate when they come technology marriage and we’re all invited. He said: “Joint development between into range of each other through the cre- Given the two technologies appear to Bluetooth and uwb is the fastest and ation of personal area networks. be meeting essentially different needs, why most economical pathway for both tech- Despite Bluetooth having a higher would the two camps want to ‘marry’? And nologies to meet the future demands of profile, uwb is the older technology, orig- now the parents have announced the companies and end users.” inating from research undertaken by the intention, if not the date, what are the Stephen Wood, a technical strategist US Navy in the early 1960s. Bluetooth, likely benefits from an alliance? with and president of the WiMedia meanwhile, is less than 10 years old. Answering from the Bluetooth point Alliance, observed: “Both technologies

New Electronics 28 June 2005 43 RF & MICROWAVE INTER DESIGN

10baseT. The same applies to uwb; peo- 3G operators. But Rosser believes the next ple want high speed, but they want it to market to move will be Asia. “We antici- work with old stuff out there.” pate large Asian companies licensing spec- But what about the uwb camp? Eric trum to support WiMedia transmissions Rosser is vice president of sales, Americas later this year, maybe early next.” and EMEA, for Staccato Communica- The general enthusiasm surrounding tions. “UWB has Bluetooth’s range, but the collaboration between Bluetooth and 500 times the speed at lower power. The uwb has tended to hide the fact that the Bluetooth announcement is interesting uwb world remains split. However, the because it seems to make uwb invaluable splits are disappearing – if only slowly. as a worldwide standard.” He acknowl- A couple of years ago, there were three edges there’s room for the two technolo- main camps. Today, there are essentially gies. “Bluetooth has a huge embedded two. On one side of the fence is the base and investment in software.” WiMedia Alliance, which includes such And it’s at the software level where heavyweights as Texas Instruments, Intel most of the work to unite the two meth- and – most recently – Microsoft. The ods will be done. Collison said the main WiMedia Alliance has absorbed MBOA – area of work will be making changes to the protocol stack. “Changing the proto- “Bluetooth is looking for higher data col stack will allow higher speed, but there is a lot of detail involved. For rates; for example, to handle media instance, rethinking how you do sig- nalling between the layers, and there are exchange and video.” implications for each layer in the stack.” Rosser points to two drivers for the Glenn Collison, CSR uwb market: cable removal and connec- tor replacement technology. “Media is now stand to achieve greater things as we becoming ubiquitous,” he claimed, “and move together toward the ideal, easy to will become even more dominant. Mean- the Multiband OFDM Alliance. Staccato use products that allow consumers to while, uwb can be a connector replace- was a founding member of MBOA and is enjoy their content and devices without ment, allowing peripheral to peripheral now a director of the WiMedia Alliance. being physically tethered to a network.” communications, rather than peripherals On the other side of the fence is the And it appears that both technologies to host pcs.” UWB Forum, including CSR, Freescale will profit from the alliance. Glenn Col- and STMicroelectronics. ST, incidentally, lison, sales director and founder of CSR, Further ahead in the US is working in both organisations. noted: “It’s a merger between two tech- UWB is further ahead in the US, where Collison noted: “We’ll work in the nologies that works well. UWB has an the Federal Communications Commis- Bluetooth SIG to make changes. That’s excellent modulation method for high sion has allowed the technology to oper- the proven body that has deployed short data rates over short distances. Bluetooth ate over the spectrum ranging from 3.1 range . It’ll be the faster route to has a well established software protocol to 10.6MHz. “The emissions are below market. But we don’t want to engage in stack, proven and deployed in more than the noise floor for intentional radiation the debate over which is the best PHY. 200million devices. But uwb is the fun- in this part of the spectrum,” Rosser con- UWB is split between the MBOA group damentally better approach because it’s tinued, “which means uwb will not and the UWB Forum, but we don’t need using a wider spectrum.” impact those transmissions.” to answer that question for a while.” He Collison believes both organisations Proponents believe uwb will support added that either route would need mod- have strengths and weaknesses. “Blue- data rates as high as 480Mbit/s. However, ifications to software, so the problem tooth,” he noted, “is looking for higher Rosser said: “It’s actually 640Mbit/s over would be solved generically. data rates; for example, to handle media the air, dropping to around 50Mbit/s at a Rosser believed the biggest market, exchange and video.” What Bluetooth range of 15m.” once the technologies have merged, will brings in exchange is backwards compat- Europe seems to be lagging in the be for single chip PHY/MACs. “We ibility. “Users demand that,” Collison approvals process. Ofcom in the UK has have in house expertise in Bluetooth,” he recognised. “Everybody wants recommended a similar spectral mask to concluded, “but we’re not being pre- gigabit ,” he continued, that in the US, but with stricter sumptuous; we’ll follow the standard, “but every chip supports controls in order to protect whatever it is.”

44 New Electronics 28 June 2005