Bluetooth Demystified / Edition 1 available in Paperback
- Pub. Date:
- McGraw-Hill Professional Publishing
About the Author
Nathan J. Muller (Huntsville, AL) is a consultant who specializes in telecommunications. He has written 1500 articles for nearly 50 magazines and 14 other books, including The Totally Wired Web Toolkit.
Table of ContentsThe Case for Bluetooth. Basic Concepts. Bluetooth Protocol Architecture. Link Management. Logical Link Control. Bluetooth General Profiles. Bluetooth Profiles for Usage Models. Bluetooth Security. Bluetooth in the Global Scheme of 3G Wireless. Appendices.
Exclusive Author Essay
Coming Soon to a Device Near You -- Bluetooth by Nathan J. Muller
A new wireless technology is poised to free us from the cable menace that continues to keep many of us shackled to our desks. This cable-conquering hero is Bluetooth, a wireless technology that provides voice and data transmission via short-range radio, allowing connections with a wide range of devices easily and quickly, without the need for cables. Up to eight devices can communicate with one another in a so-called "piconet."
Among the many things you can do with this technology is swap data and synchronize files merely by having the devices come within range of one another. Images captured with a digital camera, for example, can be dropped off at a PC for editing or to a color printer for output on photo-quality paper -- all without having to connect cables, load files, open applications, or push buttons.
The technology is a combination of circuit- and packet-switching, making it suitable for voice as well as data. Instead of fumbling with a cell phone while driving, you can wear a lightweight headset to answer a call and engage in a conversation without even taking the phone out of your briefcase or purse.
Bluetooth can be combined with other technologies to offer wholly new capabilities, such as automatically lowering the ring volume of cell phones or shutting them off as users enter quiet zones like churches, restaurants, theaters, and classrooms. Upon leaving the quiet zone, the cell phones are returned to their original settings.
No matter what the application, making connections between Bluetooth devices is as easy as powering them up. In fact, one advantage of Bluetooth is that it does not need to be set up -- it is always on, running in the background, and looking for other devices to chat with. When Bluetooth devices come within range of one another, they exchange messages so they can become aware of one another's capabilities, establish connections and, if needed, arrange for security to protect sensitive data during transmission.
Within a few years, about 80 percent of mobile phones are expected to carry a Bluetooth chip. These radio transceivers operate in the globally available ISM (industrial, scientific, and medical) radio band of 2.4 GHz, which does not require an operator's license from a regulatory agency, such as the Federal Communications Commission (FCC) in the U.S. The use of a generally available frequency band means that Bluetooth-enabled devices can be used virtually anywhere in the world and link up with one another for ad hoc networking when they come within range.
The radio link itself is very robust, using frequency-hopping spread spectrum technology to overcome interference and fading. Spread spectrum is a digital coding technique in which the signal is taken apart or "spread" so that it sounds more like noise as it is sent through the air. With the addition of frequency hopping -- having the signals hop from one frequency to another -- wireless transmissions are made even more secure. Since only the sender and receiver know the hopping sequence for coding and decoding the signal, eavesdropping is virtually impossible.
Communicator platforms of the future will combine a number of technologies and features in one device, including mobile Internet browsing, messaging, imaging, location-based applications and services, mobile telephony, personal information management, and enterprise applications. Bluetooth will be a key component of these platforms.
Ericsson is among several companies that plan to offer such products. The user interface will be based upon the VGA format and have a color touch screen, which allows for easy navigation, pen-input, and handwriting recognition. With a built-in GPS receiver, the device will also provide positioning information. And with built-in Bluetooth and infrared components, the device can connect wirelessly with virtually any other device, network, and third-party application.
There will be points of convergence between Bluetooth and other wireless technologies. Infrared and Bluetooth technologies, for example, provide complementary implementations for data exchange and voice applications. Bluetooth complements infrared's point-and-shoot ease of use with omni-directional signaling, longer distance communications, and capacity to penetrate walls. For some users, having both Bluetooth and infrared will provide the optimal short-range wireless solution. For others, the choice of adding Bluetooth or infrared will be based on the applications and intended usage.
Origins of Bluetooth
Since its initial development in 1994 by the Swedish telecommunications firm Ericsson, more than 1,800 companies worldwide have signed on as members of the Bluetooth Special Interest Group (SIG) to build products to the wireless specification and promote the new technology in the marketplace.
The engineers at Ericsson code-named the new wireless technology Bluetooth to honor a tenth-century Viking king. Harald Bluetooth reigned from 940 to 985 and is credited with uniting Denmark and bringing order to that country. Harald's name was actually Blåtand, which roughly translates into English as "Bluetooth." This has nothing to do with the color of his teeth -- Blåtand actually referred to Harald's very dark hair, which was unusual for Vikings.
As the number and types of computer and communications devices continue to proliferate, establishing connectivity between them becomes the critical issue. What is needed is an economical wireless solution that is also convenient, reliable, easy to use, and operates securely over a longer distance than infrared without requiring a clear line of sight.
Of the many emerging wireless solutions that attempt to address one or more of these needs, only one has gained global support from the broadest base of vendors representing all segments of the computer and communications markets -- Bluetooth wireless technology. When Bluetooth arrives at a device near you, it will herald a new era of unification for all devices, finally putting an end to the cable chaos that still plagues us.
Nathan Muller is a consultant in Sterling, Virginia, who specializes in advanced technology marketing, research, and education. In his 30 years of industry experience, he has published 19 books and more than 2,000 articles about computers and communications in more than 50 publications worldwide.