James Kardach, Mobile Computing Group, Intel Corporation

Index words: Bluetooth, Piconet, IEEE, 802.15, PAN, Wireless, CMOS Radio, Data Access Points, Cable Replacement, WLAN, Global, Frequency Hopping, SIG

ABSTRACT

The Bluetooth* wireless technology was created to solve a simple problem: replace the cables used on mobile devices with radio frequency waves. The technology encompasses a simple low-cost, low-power, global radio system for integration into mobile devices. Such devices can form a quick ad-hoc secure "piconet" and communicate among the connected devices. This technology creates many useful mobile usage models because the connections can occur while mobile devices are being carried in pockets and briefcases (therefore, there are no line-of-sight restrictions). This paper provides a brief description of some of these usage models and explains how the Bluetooth architecture is optimized to enable them. But first, let us answer the question: why now?

Original Bluetooth market requirements dictated integration into small handheld devices (mobile phones and computers were key clients), low cost (longterm cost of under $5 per connection point), high security, low power, and ubiquitous global use of the technology. There was no single cellular technology that could meet the global use requirement (there are five wireless phone technologies in the US alone). While WLANs had good ad-hoc networking capabilities, there was no clear market standard to pick (there are at least three varieties of IEEE 802.11 standards and a variety of other proprietary solutions in the market). Moreover, cost was too high for integration; there were no global standards, and integration into small handheld devices (like mobile phones) was a problem. As such it was decided to take a different approach: replace the cable from the "Network Adapter" (WLAN card or cellular phone) with a low-cost RF link that we now call Bluetooth.

Today the Bluetooth technology is the only specification targeted at this new market of cable replacement. Even the IEEE organization has recognized the need for wireless cable replacement technology and started the development of the 802.15 working group that focuses on this market (they call it Wireless Personal Area Networks). This specification is based on the Bluetooth technology!