What is Bluetooth?
There are lots of
different ways that electronic devices can connect to one another. Your
mouse, keyboard and printer are connected to your computer. Your personal
digital assistant (PDA) can connect to the computer with a docking cradle.
And of course, let’s not forget about the nest of wires connecting your
TV, VCR, cable box and speakers.
The art of
connecting things is becoming more and more complex every day. We
sometimes feel as though we need a Ph.D. just to set up the electronics in
our homes! Now there is a completely different way to connect electronic
equipment together called Bluetooth. Bluetooth is wireless and automatic
and has a number of interesting features that can simplify your daily
When any two
devices need to talk to each other, they have to agree on how they are
going to communicate. All of the parties in an electronic discussion need
to know whether the message they receive is the same message that was
sent. In most cases, this means developing a language of commands and
responses known as a protocol. Some types of products have a standard
protocol used by virtually all companies so that the commands for one
product will tend to have the same effect on another. Modems fall into
this category. Other product types each speak their own languages, which
means that commands intended for one specific product will seem like
gibberish if received by another. Printers are like this, with multiple
standards like PCL and PostScript.
In order to make
home electronics more user-friendly, we need a better way for all the
electronic parts of our modern life to talk to each other. That’s where
Bluetooth comes in.
Bluetooth is a
standard developed by a group of electronics manufacturers that allows any
sort of electronic equipment – from computers and cell phones to keyboards
and headphones – to make its own connections, without wires, cables or any
direct action from a user. Bluetooth is intended to be a standard that
works on two levels:
- It provides
agreement at the physical level – Bluetooth is a radio-frequency
- It also provides
agreement on when bits are sent, how many will be sent at a time and how
the parties in a conversation can be sure that the message received is
the same as the message sent.
The more than 1,000
companies belonging to the Bluetooth Special Interest Group want to let
Bluetooth’s radio communications take the place of wires for connecting
peripherals, telephones and computers.
There are already a
couple of ways to get around using wires. One is to carry information
between components via beams of light in the infrared spectrum. Infrared
is used in most television remote control systems, but it’s also used to
connect some computers with peripheral devices.
Infrared is fairly
reliable and doesn’t cost very much, but infrared is a “line of sight”
technology that you have to point at a device to make things happen.
is a little more troublesome than infrared. If you have a Palm Pilot, a
Windows CE device or a Pocket PC, you know about synchronizing data. In
synchronizing, you attach the PDA to your computer (usually with a cable),
press a button and make sure that the data on the PDA and the data on the
intended to get around the problems that come with both infrared and cable
synchronizing systems. The hardware vendors, which include Siemens, Intel,
Toshiba, Motorola and Ericsson, have developed a specification for a very
small radio module to be built into computer, telephone and entertainment
equipment. From the user’s point of view, there are three important
features to Bluetooth:
- It’s wireless.
When you travel, you don’t have to worry about keeping track of a
briefcase full of cables to attach all of your components, and you can
design your office without wondering where all the wires will go.
- You don’t have
to think about it. Bluetooth doesn’t require you to do anything special
to make it work. The devices find one another and strike up a
conversation without any user input at all.
communicates on a frequency of 2.45 gigahertz, the same frequency as baby
monitors, garage-door openers and the newest generation of cordless
With many different
Bluetooth devices in a room, you might think they’d interfere with one
another, but several devices operating on the same frequency at the same
time is unlikely because Bluetooth uses a technique called spread-spectrum
frequency hopping. The transmitters change frequencies 1,600 times every
second, meaning that more devices can make full use of a limited slice of
the radio spectrum. Since every Bluetooth transmitter uses spread-spectrum
transmitting automatically, it’s unlikely that two transmitters will be on
the same frequency at the same time.
Bluetooth-capable devices come within range of one another, an electronic
conversation takes place to determine whether they have data to share or
whether one needs to control the other. The user doesn’t have to press a
button or give a command; the electronic conversation happens
create a personal-area network that may fill a room or may encompass no
more distance than that between the cell phone on a belt-clip and the
headset on your head.
is It Called Bluetooth?
was king of Denmark in the late 900s. He managed to unite Denmark and part
of Norway into a single kingdom then introduced Christianity into Denmark.
He left a large monument, the Jelling rune stone, in memory of his
parents. He was killed in 986 during a battle with his son, Svend
Forkbeard. Choosing this name for the standard indicates how important
companies from the Baltic region (nations including Denmark, Sweden,
Norway and Finland) are to the communications industry, even if it says
little about the way the technology works.