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What Is Bluetooth?

July 25, 2002

This is a sample from Bluetooth Revealed: The Insider's Guide to an Open Specification for Global Wireless Communications, 2nd edition (ISBN: 0-13-067237-8) from Prentice Hall.

By Brent A. Miller, et al.

The term Bluetooth TM 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 technology 2 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 engieers 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.

SIG Progression

As the specification evolved and awareness of the technology and the SIG increased, many other companies joined the SIG as adopters; adopters are entitled to a royalty-free license to produce products with Bluetooth wireless communication based on the specification and can receive and comment upon early versions of SIG publications. Today there are more than 2,400 adopter members of the SIG, representing academia and industries such as consumer electronics, automotive, silicon manufacturing, consulting, telecommunications and many others. The original objective of the SIG was to develop, as rapidly as possible, an open specification that was sufficiently complete to enable implementations. By carefully organizing the SIG and making use of frequent in-person meetings supplemented by even more frequent conference calls and e-mail exchanges, the SIG produced a thorough specification (together, the volume 1 core specification and volume 2 profiles number over 1,500 pages) in about one and one-half years (version 1.0 of the specification, including profiles, was published in July 1999).

Initially, the SIG organized itself into several working groups, each with a focus on a specific part of the technology or on some supporting service. These working groups included:

  • the air interface working group, which focused on the radio and baseband layers;
  • the software working group, which developed the specification for the protocol stack;
  • the interoperability working group, which focused on profiles;
  • the compliance working group, which defined the testing, compliance and certification process;
  • the legal working group, which managed the legal affairs of the SIG such as membership and intellectual property agreements; and
  • the marketing working group, which promoted the technology and helped to generate the marketing requirements that the specification was to address.

Some of the larger working groups, such as the software working group, were further divided into task forces focusing on a particular layer of the Bluetooth protocol stack. Coordinating all of these working groups and governing the overall SIG was a program management committee composed of voting representatives from each of the promoter companies.

During the one and one-half years that the SIG was developing the version 1.0 specification, working groups and task forces met and conducted their business both together and separately. Full working group (and sometimes complete SIG) meetings were held every few weeks, often hosted by promoter companies in locations where many of their involved personnel worked. These included Ericsson's Lund, Sweden facility; Intel's Chandler, Arizona software laboratory; IBM's sites in Research Triangle Park, North Carolina and Hawthorne, New York; and Nokia's Tampere, Finland location. Most working groups and task forces also held weekly conference calls. In addition, e-mail distribution lists were used liberally and in fact were a primary method for conducting working group business. Because of the geographic diversity of the people involved, it was difficult to find mutually convenient times for frequent voice conversations;3 thus electronic mail quickly became a convenient and heavily used means of communication (in many respects it allowed specification development around the clock). Indeed, the official ratification of the final versions of the specification, profiles and errata was conducted using the e-mail reflectors.

In December 1999, four new promoter companies (3Com Corporation, Lucent Technologies Inc., Microsoft Corporation and Motorola, Inc., some of whom had made contributions to the original specification as adopter companies) joined the SIG. At that time the SIG was reorganized, adding a membership level called an associate member as well as formalizing the structure of the SIG and the specification development process. Today the SIG has several working groups, each with its own charter, along with a Bluetooth Architecture Review Board (BARB) that oversees the specification development and maintenance process. The group remains very active today in maintaining the existing documentation and in creating enhancements to the specification, along with new profiles. This work is discussed in further detail in Part 5 of this book.

It easily can be seen that it took an enormous effort to develop over 1,500 pages of complex and detailed information in just over a year's time. For many in the SIG this became their full-time job or at least a primary responsibility. Issues, both technical and non-technical, inevitably arose and were handled through discussion and voting when necessary, but in general the development and refinement of specifications and profiles progressed in an exemplary manner. A spirit of cooperation, fostered by the common objective of producing an open specification for this important new technology, usually carried the day (at least in the authors' experience in the software and interoperability working groups).

The Bluetooth Name and History

Bluetooth is notable in the high-technology industry in several respects, but in particular its name garners much attention. Most new industry initiatives are known by a name that describes their associated technology or its application and often they quickly become known by an acronym describing the full name. Why wasn't the technology called, for example, "Short-Range Wireless Radio," or SRWR, or some other descriptive name? The answer lies in the heritage (and perhaps the whimsy) of the original inventors. There are numerous histories and accounts of the Bluetooth namesake and how that name came to be chosen; the generally accepted story and facts are cited here.

Harald Blåtand was King of Denmark from approximately A.D. 940 to 985. During his reign King Harald is reported to have united Denmark and Norway and to have brought Christianity to Scandinavia. Apparently "Blåtand" translates, at least loosely, to "Blue Tooth." The origins of this name are uncertain, although it was relatively common during this time for kings to have a distinguishing name. (Some histories say that the name is attributed to Harald's dark complexion; some accounts even indicate that King Harald was known for teeth of a bluish hue resulting from his fondness for blueberries, although this is probably folklore.) For a technology with its origins in Scandinavia, it seemed appropriate to the SIG founders to name the organization that was intended to unify multinational companies after a Scandinavian king who united countries. Thus was born the Bluetooth name, which initially was an unofficial code name for the project but today has become the trademark name (see footnote 1 on page 3) of the technology and the SIG. Figure 1–1 shows the Bluetooth logo, inspired by the initials "H B" for Harald Bluetooth.

Figure 1–1  The Bluetooth logo, a trademark owned by the Bluetooth Special Interest Group, Inc., U.S.A.

Bluetooth wireless communication has engendered tremendous interest since the SIG's formation was announced. Articles in many leading computer-industry trade press publications and in quite a few of the mainstream media have appeared with some frequency. Many analysts such as the Cahners In-Stat Group and the Gartner Group DataQuest now include Bluetooth wireless communications in their studies and forecasts. Between November 1998 and June 2000 at least nine major Bluetooth developers conferences were held in cities including Atlanta, Tokyo, London, Amsterdam, Geneva, Los Angeles and Monte Carlo. The SIG-sponsored conference in December 2000 in Los Angeles attracted over 3,000 attendees, including developers, analysts, customers and others from diverse geographies and industries.

This is a sample from Bluetooth Revealed: The Insider's Guide to an Open Specification for Global Wireless Communications, 2nd edition (ISBN: 0-13-067237-8) from Prentice Hall. For the full text, visit ©2001 Pearson Education. All Rights Reserved.

1. Bluetooth is a trademark owned by the Bluetooth Special Interest Group, Inc., U.S.A.

2. The Bluetooth Brand Book contains guidelines for the use of the term Bluetooth. To be consistent with those guidelines, we will henceforth use the term as an adjective, not as a standalone noun.

3. When it was 9:00 a.m. on the west coast of the United States, where many involved parties worked and lived, it often (depending upon daylight-saving time observance) was 7:00 p.m. in Finland and 2:00 a.m. the following morning in Japan).

4. In general, our references to the contents of the version 1.0 specification are applicable to any ofthe 1.x family of specifications (which, as of this writing, includes versions 1.0A, 1.0B, and 1.1).

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