Taking wireless to a whole new level....

Bluetooth Technology

Bluetooth wireless technology is a short-range communications technology intended to replace the cables connecting portable and/or fixed devices while maintaining high levels of security. The key features of Bluetooth technology are robustness, low power, and low cost. The Bluetooth specification defines a uniform structure for a wide range of devices to connect and communicate with each other.

Bluetooth Basics

Core Specification Versions

* Version 2.0 + Enhanced Data Rate (EDR), adopted November, 2004
* Version 1.2, adopted November, 2003


Bluetooth technology operates in the unlicensed industrial, scientific and medical (ISM) band at 2.4 to 2.485 GHz, using a spread spectrum, frequency hopping, full-duplex signal at a nominal rate of 1600 hops/sec. The 2.4 GHz ISM band is available and unlicensed in most countries.


Bluetooth technology's adaptive frequency hopping (AFH) capability was designed to reduce interference between wireless technologies sharing the 2.4 GHz spectrum. AFH works within the spectrum to take advantage of the available frequency. This is done by detecting other devices in the spectrum and avoiding the frequencies they are using. This adaptive hopping allows for more efficient transmission within the spectrum, providing users with greater performance even if using other technologies along with Bluetooth technology. The signal hops among 79 frequencies at 1 MHz intervals to give a high degree of interference immunity.


The effective range of Bluetooth devices is 32 feet (10 meters).

Bluetooth is designed for very low power use, and the transmission range will only be 10m, about 30ft. High-powered Bluetooth devices will enable ranges up to 100m (300ft). Considering the design philosophy behind Bluetooth, even the 10m range is adequate for the purposes Bluetooth is intended for. Later versions of the Bluetooth spec may allow longer ranges.

The operating range depends on the device class:

* Class 3 radios have a range of up to 1 meter or 3 feet
* Class 2 radios most commonly found in mobile devices have a range of 10 meters or 30 feet
* Class 1 radios used primarily in industrial use cases have a range of 100 meters or 300 feet


The most commonly used radio is Class 2 and uses 2.5 mW of power. Bluetooth technology is designed to have very low power consumption. This is reinforced in the specification by allowing radios to be powered down when inactive.

Data Rate

Bluetooth transfers data at the rate of 1 Mbps, which is from three to eight times the average speed of parallel and serial ports, respectively.

1 Mbps for Version 1.2;
Up to 3 Mbps supported for Version 2.0 + EDR

Bluetooth Technology Benefits


The Bluetooth wireless technology specification is available free-of-charge to our member companies around the globe. Manufacturers from many industries are busy implementing the technology in their products to reduce the clutter of wires, make seamless connections, stream stereo audio, transfer data or carry voice communications. Bluetooth technology operates in the 2.4 GHz, one of the unlicensed industrial, scientific, medical (ISM) radio bands. As such, there is no cost for the use of Bluetooth technology. While you must subscribe to a cellular provider to use GSM or CDMA, with Bluetooth technology there is no cost associated with the use beyond the cost of your device.

Range of Devices

Bluetooth technology is available in an unprecedented range of applications from mobile phones to automobiles to medical devices for use by consumers, industrial markets, enterprises, and more. The low power consumption, small size and low cost of the chipset solution enables Bluetooth technology to be used in the tiniest of devices. Have a look at the wide range products made available by our members in the Bluetooth product directory and the component product listing.

Ease of Use

Bluetooth technology is an ad hoc technology that requires no fixed infrastructure and is simple to install and set up. You don't need wires to get connected. The process for a new user is easy � you get a Bluetooth branded product, check the profiles available and connect it to another Bluetooth device with the same profiles. The subsequent PIN code process is as easy as when you identify yourself at the ATM machine. When out-and-about, you carry your personal area network (PAN) with you and can even connect to others.


Bluetooth is extremely secure in that it employs several layers of data encryption and user authentication measures. Bluetooth devices use a combination of the Personal Identification Number (PIN) and a Bluetooth address to identify other Bluetooth devices. Data encryption (i.e., 128-bit) can be used to further enhance the degree of Bluetooth security. The transmission scheme (FHSS) provides another level of security in itself. Instead of transmitting over one frequency within the 2.4 GHz band, Bluetooth radios use a fast frequency-hopping spread spectrum (FHSS) technique, allowing only synchronized receivers to access the transmitted data.

The following are the security components which make up the Bluetooth chip:
Bluetooth Device Address 48-bit address
Authentication Key 128-bit random number
Encryption Key 8-128 bits in length
Random Number 128-bit random number

Levels of Security

1. Trusted- unrestricted access
2. Not Trusted- restricted access
1. Require authentication and authorization
2. Authentication only
3. Open to al devices
Unit Key E21 Generated while initialization of link occurs. Stored in memory. Used when one device wishes to use the other's unit key.
Combination Key E21 Generated by both devices. Devices exchange their random numbers and calculate combination key.
Master Key E22 Generated by the master device. Temporarily used by devices, then purged.
The first link between two devices must be established by the link key. This link key is a 128-bit random number. This link key can be one of the following: The Personal Identification Number is part of the E21 algorithm which is the algorithm which first establishes a connection between two devices(initialization key).


The Bluetooth specification 1.0 describes the link encryption algorithm as a stream cipher using 4 LFSR (linear feedback shift registers). The sum of the width of the LFSRs is 128, and the spec says "the effective key length is selectable between 8 and 128 bits". This arrangement allows Bluetooth to be used in countries with regulations limiting encryption strength, and "facilitate a future upgrade path for the security without the need for a costly redesign of the algorithms and encryption hardware" according to the Bluetooth specification. Key generation and authentication seems to be using the 8-round SAFER+ encryption algorithm. The information available suggests that Bluetooth security will be adequate for most purposes; but users with higher security requirements will need to employ stronger algorithms to ensure the security of their data.

Concerns with Security

There are several concerns within Bluetooth security as some have proven that the link between two devices can be easily intercepted. Recently, Nokia is one of the companies that has admitted to being susceptible to outside attacks when using the Bluetooth technology.

One major concern is the use of the PIN to generate the link between two devices. This PIN could be as short as 4 digits, leaving a possibility of 10,000 different combinations. Another issued that needs to be addressed is the security behind the Bluetooth device address. When a connection is made to a Bluetooth device using this unique address, information can be logged and thus invasion of privacy can occur.

A concrete example of Bluetooth being cracked is when Nokia was a victim of backdoor attack. The program used as a hacking tool is called bluesnarf. When a Bluetooth connection was established between two devices, there is a possibility that the trusted user uses this backdoor hacking tool to gain unauthorized access.


Bluetooth. March 30, 2007
How Bluetooth Works. March 30, 2007
What Is Bluetooth. March 30, 2007

See Also

Speed of WiMax
Quality of Service
Advanced Encryption Standard
Networking with House Wiring
Iris Biometric System