What Is Bluetooth?
The term Bluetooth™1 refers to an open specification for a technology to enable short-range wireless voice and data communications anywhere in the world. This simple and straightforward description of the Bluetooth technology2 includes several points that are key to its understanding:
Open specification: The Bluetooth Special Interest Group (SIG) has produced a specification for Bluetooth wireless communication that is publicly available and royalty free. To help foster widespread acceptance of the technology, a truly open specification has been a fundamental objective of the SIG since its formation.
Short-range wireless: There are many instances of short-range digital communication among computing and communications devices; today much of that communication takes place over cables. These cables connect to a multitude of devices using a wide variety of connectors with many combinations of shapes, sizes and number of pins; this plethora of cables can become quite burdensome to users. With Bluetooth technology, these devices can communicate without wires over a single air-interface, using radio waves to transmit and receive data. Bluetooth wireless technology is specifically designed for short-range (nominally 10 meters) communications; one result of this design is very low power consumption, making the technology well suited for use with small, portable personal devices that typically are powered by batteries.
Voice and data: Traditional lines between computing and communications environments are continually becoming less distinct. Voice is now commonly transmitted and stored in digital formats. Voice appliances such as mobile telephones are also used for data applications such as information access or browsing. Through voice recognition, computers can be controlled by voice, and through voice synthesis, computers can produce audio output in addition to visual output. Some wireless communication technologies are designed to carry only voice; others handle only data traffic. Bluetooth wireless communication makes provisions for both voice and data, and thus it is an ideal technology for unifying these worlds by enabling all sorts of devices to communicate using either or both of these content types.
Anywhere in the world: The telecommunications industry is highly regulated in many parts of the world. Telephone systems, for example, must comply with many governmental restrictions, and telephony standards vary by country. Many forms of wireless communications are also regulated; radio frequency spectrum usage often requires a license with strict transmission power obligations. However, some portions of the available radio frequency spectrum may be used without license, and Bluetooth wireless communications operate within a chosen frequency spectrum that is unlicensed throughout the world (with certain limitations and restrictions that are discussed later in the book). Thus devices that employ Bluetooth wireless communication can be used unmodified, no matter where a person might be.
The Bluetooth short-range wireless technology is ideally suited for replacing the many cables that are associated with today's pervasive devices. The Bluetooth specification ([BTSIG99], hereafter referred to as the specification) explicitly defines a means for wireless transports to replace serial cables, such as those used with modems, digital cameras and personal digital assistants; the technology could also be used to replace other cables, such as those associated with computer peripherals (including printers, scanners, keyboards, mice and others). Moreover, wireless connectivity among a plethora of fixed and mobile devices can enable many other new and exciting usage scenarios beyond simple cable replacement. In this book we explore various applications of the technology.
Important characteristics and applications of Bluetooth wireless communications are examined in detail in this book. The Bluetooth specification is explained in easy-to-understand terms with the benefit of the authors' experiences, gained while participating in its development. If the Bluetooth wireless technology succeeds in the marketplace to the extent predicted by many analysts, it has the potential to change people's lives and the way that people think about and interact with computing and communication devices. Understanding this emerging technology can benefit not only industry professionals, but also consumers who can use and obtain value from it.
The Bluetooth Special Interest Group
As previously described, Bluetooth wireless communication is embodied as a technology specification. This specification is a result of the cooperation of many companies within an organization called the Bluetooth Special Interest Group, or SIG. There is no "Bluetooth headquarters"; until 2001 there was no "Bluetooth corporation" or any sort of legally incorporated entity. Originally, the SIG was governed by legal agreements among the member parties but it was not a company unto itself. In February 2001, the SIG incorporated and is now officially known as the Bluetooth Special Interest Group, Inc. The SIG should not be construed as a formal standards body; rather it is an organization chartered to define and promote the technology. In fulfilling this charter, the SIG depends upon the contributions and participation of its member companies. Clearly a major task of the SIG has been to develop the specification, but other SIG activities include joint work with other consortia and standards and regulatory bodies, educational and promotional events such as developers' conferences and the definition of a testing and certification process.
Technology and SIG Origins
Bluetooth wireless technology was conceived by engineers at Swedish telecommunications manufacturer Telefonaktiebolaget LM Ericsson (hereafter, Ericsson) who realized the potential of global short-range wireless communications. In 1994 Ericsson had begun a project to study the feasibility of a low-power, low-cost radio interface to eliminate cables between mobile phones and their accessories.
In today's computing and communications industries, proprietary new technologies rarely succeed; customers clearly prefer to purchase and deploy technologies based on industry standards. By creating a level playing field, standards give customers greater freedom to choose from among competing platforms and solutions, to protect their investments as technologies evolve and to leverage (and in some cases, also influence) multicompany skills and organizations devoted to developing the standards.
In this industry environment, the Ericsson inventors understood that the technology was more likely to be widely accepted, and thus could be more powerful, if it was adopted and refined by an industry group that could produce an open, common specification. In early 1998, leading companies in the computing and telecommunication industries formed the Bluetooth SIG to focus on developing exactly such an open specification. The founding companies of the SIG are Ericsson, Intel Corporation, International Business Machines Corporation (IBM), Nokia Corporation and Toshiba Corporation. These companies formed the original core group (known as promoter companies) of the SIG. The SIG was publicly announced in May 1998 with a charter to produce an open specification for hardware and software that would promote interoperable, cross-platform implementations for all kinds of devices.
Although open standards can be quite advantageous, one potential disadvantage of standards bodies, consortia, special interest groups and similar organizations is that they tend toward inherent inefficiencies as compared to single-company efforts. Within a single company there is often one overriding objective for developing new technology; in a multi-company effort each participant may have different, perhaps even competing goals. Even with modern ways to exchange information, such as electronic mail, group interactions are still likely to be more efficient within a single organization than throughout a group composed of many organizations (especially when those organizations are geographically diverse, as is the case for the members of the SIGtelephone calls, for example, have to take into account the fact that the people involved reside in time zones with little or no overlap of typical working [or even waking] hours). To overcome some of these potential drawbacks, the SIG intentionally was created with a small number of companies committed to the rapid development of the specification who were willing to expend the resources necessary to accomplish this.