Bluetooth

Bluetooth is the name for a short-range radio frequency (RF) technology that operates at 2.4 GHz and is capable of transmitting voice and data signals. 

Why is the technology called Bluetooth?
The heart of the Bluetooth brand identity is the name, which refers to the Danish king Harald "Bluetooth" Blaatand who unified Denmark and Norway.  In the beginning of the Bluetooth wireless technology era, Bluetooth was aimed at unifying the telecom and computing industries.

Where can I use Bluetooth wireless?
Bluetooth can be used to wirelessly synchronize and transfer data among devices.  Bluetooth can be thought of as a cable replacement technology.  Typical uses include automatically synchronizing contact and calendar information among desktop, notebook and palmtop computers without connecting cables.  Bluetooth can also be used to access a network or the Internet with a notebook computer by connecting wirelessly to a cellular phone.

Is Bluetooth wireless the same as the Medical Center's wireless network?
No.  The two technologies are very different.  Bluetooth can be viewed as, and often referred to, as a Personal Area Network because the nature of how the technology works.  The maximum effective range of Bluetooth devices is about 33 feet (10 meters).  The Medical Center's wireless cloud is a Wi-Fi 802.11b/g network, used for much longer range communication (hundreds of feet). 

How secure is a Bluetooth?
Bluetooth is secure, however, there have been a few recorded instances of reported vulnerabilities.  Bluetooth 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 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.  Once you have configured your Bluetooth device(s) to communicate to your computer/laptop or phone, we recommend you turn the host device's Bluetooth settings to "Not Discoverable."

What is Frequency-Hopping Spread-Spectrum (FHSS)?
Frequency-Hopping Spread-Spectrum (FHSS) is a modulation scheme that uses a narrow band carrier that changes frequency in a pattern known to both transmitter and receiver.  When properly synchronized, it maintains a single logical channel.  To an unsynchronized receiver, FHSS appears as short-duration impulse noise.  More simply, the data is broken down into packets and transmitted to the receiver of other devices over numerous "hop frequencies" (79 total) in a pseudo random pattern.  Only transmitters and receivers that are synchronized on the same hop frequency pattern will have access to the transmitted data. The transmitter switches hop frequencies 1,600 times per second to assure a high degree of data security.

Will other RF (Radio Frequency) devices interfere with Bluetooth Devices?
Unlikely.  Bluetooth radios operate on the unlicensed 2.4 GHz (Industrial, Scientific and Medical) frequency band that is shared among other devices (microwave ovens, cordless phones, garage door openers, etc.).  Bluetooth radios switch frequencies at such a rapid pace and the data packets are so small that interference from other RF sources is unlikely.

Will Bluetooth and Wireless LAN (Wi-Fi LAN) interfere with each other?
Unlikely.  Both Bluetooth and WLAN (Wi-Fi) can co-exist.  Since Bluetooth devices use Frequency Hopping and most WLANs use Direct Sequence Spreading techniques they each appear as background noise to the other and should not cause any perceivable performance issues.

What is the data throughput speed of a Bluetooth connection?
Bluetooth transfers data at a rate of 721 Kbps, which is from three to eight times the average speed of parallel and serial ports, respectively.  This bandwidth is capable of transmitting voice, data, video and still images.

What is the typical range of Bluetooth transmitter/receivers?
Bluetooth is designed for very low power use, and the typical transmission range will only be about 30 ft.  Next generations of the Bluetooth specification may allow longer ranges.

What kind of encryption will be used for Bluetooth security?
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.

Is Bluetooth practical for use with mobile devices?
Yes.  One concern for mobile computing users is power consumption.  Bluetooth radios draw very low power, as little as 0.3mA in standby mode and 30mA during sustained data transmissions.  Bluetooth radios alternate among power-saving modes in which device activity is lowered to maximize the mobile power supply.

What is a Personal Area Network (PAN)?
A Personal Area Network is another name for a Bluetooth Piconet.

What is it really -- a technology, a standard, an initiative, or a product?
Bluetooth wireless technology is a de facto standard, as well as a specification for small-form factor, low-cost, short range radio links between mobile PCs, mobile phones and other portable devices. The Bluetooth Special Interest Group is an industry group consisting of leaders in the telecommunications, computing, and networking industries that are driving development of the technology and bringing it to market.

Learn more

The Official Bluetooth Info Web Site
Site sponsored by the Bluetooth Special Interest Group (SIG), a trade association

The Official Bluetooth Membership Site
Another site sponsored by the Bluetooth Special Interest Group (SIG)