Bluetooth has a lot to offer with an increasingly difficult market place. Bluetooth helps to bring
with it the promise of freedom from the cables and simplicity in networking that has yet to be matched
by LAN (Local Area Network).
In the key marketplace, of wireless and handheld devices, the closest competitor to Bluetooth is
infrared. Infrared holds many key features, although the line of sight it provides doesn't go
through walls or through obstacles like that of the Bluetooth technology.
Unlike infrared, Bluetooth isn't a line of sight and it provides ranges of up to 100 meters. Bluetooth
is also low power and low processing with an overhead protocol. What this means, is that it's
ideal for integration into small battery powered devices. To put it short, the applications with
Bluetooth are virtually endless.
Disadvantages
Bluetooth has several positive features and one would be extremely hard pressed to find downsides
when given the current competition. The only real downsides are the data rate and security. Infrared
can have data rates of up to 4 MBps, which provides very fast rates for data transfer, while Bluetooth
only offers 1 MBps.
For this very reason, infrared has yet to be dispensed with completely and is considered by
many to be the complimentary technology to that of Bluetooth. Infrared has inherent security due
to its line of sight.
The greater range and radio frequency (RF) of Bluetooth make it much more open to interception and
attack. For this reason, security is a very key aspect to the Bluetooth specification.
Although there are very few disadvantages, Bluetooth still remains the best for short range wireless
technology. Those who have tried it love it, and they know for a fact that Bluetooth will be
around for years to come.
Sunday, September 25, 2011
How Bluetooth Works
Bluetooth devices will normally operate at 2.4 GHZ in the license free, globally available ISM radio
band. The advantage to this band includes worldwide availability and compatibility. A disadvantage to
this however, is that the devices must share this band with other RF emitters. This includes
automobile security systems, other wireless devices, and other noise sources, such as microwaves.
To overcome this challenge, Bluetooth employs a fast frequency hopping scheme and therefore uses
shorter packets than other standards within the ISM band. This scheme helps to make Bluetooth
communication more robust and more secure.
Frequency hopping
Frequency hopping is basically jumping from frequency to frequency within the ISM radio band. After a
bluetooth device sends or receives a packet, it and the device (or devices) it's communicating with
hop to another frequency before the next packet is sent. This scheme offers three advantages:
1. Allows Bluetooth devices to use the entirety of the available ISM band, while never
transmitting from a fixed frequency for more than a short period of time. This helps insure that
Bluetooth conforms to the ISM restrictions on the transmission quantity per frequency.
2. Ensures that any interference won't last long. Any packet that doesn't arrive safely
to its destination can be resent to the next frequency.
3. Provides a base level of security as it's very hard for an eavesdropping device to predict
which frequency the Bluetooth devices will usenext.
The connected devices however, must agree upon the frequency they will use next. The specification
in Bluetooth ensures this in two ways. First, it defines a master and slave type relationship between
bluetooth devices. Next, it specifies an algorithm that uses device specific information when
calculating the frequency hop sequences.
A Bluetooth device that operates in master mode can communicate with up to seven devices that are set in
slave mode. To each of the slaves, the master Bluetooth device will send its own unique address
and the value of its own internal clock. The information sent is then used to calculate the
frequency hop sequences.
Because the master device and each of the slave devices use the same algorithm with the same initial
input, the connected devices will always arrive together at the next frequency that they have agreed
upon.
As a replacement for cable technology, it's no wonder that Bluetooth devices are usually battery
powered, such as wireless mice and battery powered cell phones. To conserve the power, most devices
operate in low power. This helps to give Bluetooth devices a range of around 5 - 10 meters.
This range is far enough for wireless communication but close enough to avoid drawing too much power
from the power source of the device.
band. The advantage to this band includes worldwide availability and compatibility. A disadvantage to
this however, is that the devices must share this band with other RF emitters. This includes
automobile security systems, other wireless devices, and other noise sources, such as microwaves.
To overcome this challenge, Bluetooth employs a fast frequency hopping scheme and therefore uses
shorter packets than other standards within the ISM band. This scheme helps to make Bluetooth
communication more robust and more secure.
Frequency hopping
Frequency hopping is basically jumping from frequency to frequency within the ISM radio band. After a
bluetooth device sends or receives a packet, it and the device (or devices) it's communicating with
hop to another frequency before the next packet is sent. This scheme offers three advantages:
1. Allows Bluetooth devices to use the entirety of the available ISM band, while never
transmitting from a fixed frequency for more than a short period of time. This helps insure that
Bluetooth conforms to the ISM restrictions on the transmission quantity per frequency.
2. Ensures that any interference won't last long. Any packet that doesn't arrive safely
to its destination can be resent to the next frequency.
3. Provides a base level of security as it's very hard for an eavesdropping device to predict
which frequency the Bluetooth devices will usenext.
The connected devices however, must agree upon the frequency they will use next. The specification
in Bluetooth ensures this in two ways. First, it defines a master and slave type relationship between
bluetooth devices. Next, it specifies an algorithm that uses device specific information when
calculating the frequency hop sequences.
A Bluetooth device that operates in master mode can communicate with up to seven devices that are set in
slave mode. To each of the slaves, the master Bluetooth device will send its own unique address
and the value of its own internal clock. The information sent is then used to calculate the
frequency hop sequences.
Because the master device and each of the slave devices use the same algorithm with the same initial
input, the connected devices will always arrive together at the next frequency that they have agreed
upon.
As a replacement for cable technology, it's no wonder that Bluetooth devices are usually battery
powered, such as wireless mice and battery powered cell phones. To conserve the power, most devices
operate in low power. This helps to give Bluetooth devices a range of around 5 - 10 meters.
This range is far enough for wireless communication but close enough to avoid drawing too much power
from the power source of the device.
Introduction To Bluetooth
Bluetooth was designed to allow low bandwidth wireless connections to become easy to use so even those who are new to wireless can use them. Version 1.1 of Bluetooth describes a low power, short range wireless networking technology that uses radio waves to send data at rates up to 720 kilobits a second.
The specification for Bluetooth provides for different classes of radio that allow transmission ranges of
up to 100 meters by boosting the radio power. The technology of Bluetooth isn't limited to line of
sight transmission since it uses directional waves that are capable of transmitting through many
obstructions.
Bluetooth is an industry standard communication of wireless, meaning that it enables the connection
of other devices as well, such as cell phones, computers, digital cameras, and other types of
electronic devices. The specification of Bluetooth defines a radio system and a "stack" of protocol
layers and profiles. The highest layer is the application layer, while the lowest layer is the
radio.
The wireless technology of Bluetooth is positioned to revolutionize the personal connectivity market
by providing freedom from inconvenient fixed type lines.
The specification for Bluetooth eliminates the need for cables by providing a small form factor, low
cost wireless solution that will link computers, cell phones, and other electronics. Bluetooth
also allows users to connect many ranges of devices quickly and easily and expands communications
capabilities as well.
The size of the Bluetooth radio is amazing, as a Bluetooth radio can be built into one or two very
small microchips then integrated into any electronic device where wireless operations would be an
advantage.
Bluetooth also offers a robust link, which ensures that normal operating circumstances are not
interrupted by interference from other signals that are operating in the same frequency band.
Also known for its worldwide operation, Bluetooth radio operates in the 2.4 GHz frequency band, which
is license free and available to any type of radio system in the world. No matter where you
are in the world, you count on Bluetooth to work.
Security is also important. Offering advanced security mechanisms, Bluetooth ensures a high level
of security. Therefore, authentification will prevent unauthorized acess to important data and
make it very difficult to listen in.
Bluetooth also boasts power optimization. The radio is power friendly and the software for Bluetooth
is very configurable, limiting the power consumption of equipment. The radio itself only consumes a
small amount of power from a cellular phone.
The specification for Bluetooth provides for different classes of radio that allow transmission ranges of
up to 100 meters by boosting the radio power. The technology of Bluetooth isn't limited to line of
sight transmission since it uses directional waves that are capable of transmitting through many
obstructions.
Bluetooth is an industry standard communication of wireless, meaning that it enables the connection
of other devices as well, such as cell phones, computers, digital cameras, and other types of
electronic devices. The specification of Bluetooth defines a radio system and a "stack" of protocol
layers and profiles. The highest layer is the application layer, while the lowest layer is the
radio.
The wireless technology of Bluetooth is positioned to revolutionize the personal connectivity market
by providing freedom from inconvenient fixed type lines.
The specification for Bluetooth eliminates the need for cables by providing a small form factor, low
cost wireless solution that will link computers, cell phones, and other electronics. Bluetooth
also allows users to connect many ranges of devices quickly and easily and expands communications
capabilities as well.
The size of the Bluetooth radio is amazing, as a Bluetooth radio can be built into one or two very
small microchips then integrated into any electronic device where wireless operations would be an
advantage.
Bluetooth also offers a robust link, which ensures that normal operating circumstances are not
interrupted by interference from other signals that are operating in the same frequency band.
Also known for its worldwide operation, Bluetooth radio operates in the 2.4 GHz frequency band, which
is license free and available to any type of radio system in the world. No matter where you
are in the world, you count on Bluetooth to work.
Security is also important. Offering advanced security mechanisms, Bluetooth ensures a high level
of security. Therefore, authentification will prevent unauthorized acess to important data and
make it very difficult to listen in.
Bluetooth also boasts power optimization. The radio is power friendly and the software for Bluetooth
is very configurable, limiting the power consumption of equipment. The radio itself only consumes a
small amount of power from a cellular phone.
Subscribe to:
Posts (Atom)