Jennifer Bray of CSR attempts to counter the propaganda coming from some 802.11b evangelists.

That may be a contentious headline for this piece, but the voice of Bluetooth needs to be heard above recent 802.11b propaganda - mainly emanating from the US. Like Mark Twain, any reports of its demise are an exaggeration. The truth is, 802.11b and Bluetooth are highly complementary and Bluetooth has already penetrated deeply into the fabric of the world's top OEMs.

Take a moment to consider the major differences between Bluetooth and 802.11b.

Data and voice: 802.11b is a higher bandwidth standard optimised for rapid transfer of large amounts of data. Although voice can be sent (as compressed files), it's not ideal for audio. Bluetooth has a reasonable data transfer rate suitable for handling moderately sized data files, plus designed-for-purpose audio channel capability.

Chipsets: the spread-spectrum, high data burst handling capabilities, and range of 802.11b make it a more complex standard. Today it takes typically three chips to implement, compared with the two or one of Class 2 Bluetooth silicon. And while it's always conceivable that further integration will take place, there's no getting away from the fact that it's behind Bluetooth in the integration stakes, and will always be so because of its relative complexity. That basic issue unfolds into cost, real-estate and power consumption strands, each of which has a major impact on applications potential, particularly at the smaller end of the portable gadget industry.

Communications protocol layers: 802.11b is designed as a communications channel to a host processor running TCP/IP. Bluetooth defines more communications protocol layers and implements real applications. For the foreseeable medium-term future at least, this distinguishes a clear difference in the potential for each standard in embedded systems.

Security: 802.11b currently offers only 64 bit keylength encryption, which is much less secure than the 128 bits of Bluetooth - as the AirSnort publicity demonstrated last year.

These differences all lead to a natural partitioning of applications. For the out-and-out business applications involving large amounts of data transfer, 802.11b is undoubtedly a good choice. If the system involves audio, only moderate sized data transfers, or if it's targeted at consumer goods - Bluetooth is best.

Starting from today's mainstream Bluetooth applications of the mobile phone and PCs, the cost, size and power consumption characteristics of Bluetooth will undoubtedly edge it further towards the single-chip embedded systems market.

It's hard to see how 802.11b could ever be crammed into a headset, let alone some of the extreme cost-sensitive embedded Bluetooth applications such as luggage security tags and handheld games for kids.

So, for phones, cameras, portable games and gadgets, and linking devices to PCs and networks, Bluetooth's a must. What's more likely (as we're already seeing) is that business equipment OEMs will come out with dual-purpose Bluetooth and 802.11b capability.

You might encapsulate this partitioning as 802.11b for corporate applications, Bluetooth for everything else. Given that scenario, Microsoft's initial support for 802.11 is understandable, but Bluetooth will surely follow. Don't forget that Microsoft does support Bluetooth for the Windows CE.NET operating system. Future releases of Windows XP will also support Bluetooth.

Indeed, the arguments are so clear and so strong, it's hard to imagine how there is even a question mark over Bluetooth. One can only put it down to worries and fear of business planners given the recent downturn, and/or uninformed and under-researched reporters.

Joyce Putscher, director of converging markets & technologies at In-Stat/MDR and principal Bluetooth analyst said, "Those who think it's going to be one technology or the other just don't get it. These two systems are designed primarily to do different things. Sure, for full-blown wireless LAN applications, you're going to have 802.11. But the bottom line is that you don't need a LAN for a great number of applications. Bluetooth will enable new ways of doing things wirelessly with more flexibility, and enable new ways of communicating such as 'chat', exchanging e-business cards, and more, as well as connecting to the Internet."

Explaining the growth in the Bluetooth chip market, Putscher added, "We saw Bluetooth chipset shipments grow from 524K units in 2000 to an estimated 13 million in 2001. That resulted in Bluetooth chipsets overtaking 802.11x shipments of all flavours by almost a factor of two. This is a dramatic comparison to the flat 802.11b shipments in 2001. We expect a compound annual growth rate of over 300% in sales of Bluetooth chipsets over the next five years."

This piece opened by asserting that Bluetooth has already penetrated deeply into the fabric of the world's leading EOEMs - I base that conclusion on CSR's own experience with its leading customers including: Sony, Compaq, IBM, 3Com, LG, NEC, Fujitsu and TDK.

Pulished in Embedded Systems May 2002