What is BLUETOOTH wireless technology?
BLUETOOTH wireless technology is a short-range wireless technology that enables wireless data communication between digital devices, such as a computer and digital camera. BLUETOOTH wireless technology operates within a range of about 10 m (30 feet).
Connecting two devices as necessary is common, but some devices can be connected to multiple devices at the same time.
You do not need to use a cable for connection, nor is it necessary for the devices to face one another, such is the case with infrared technology. For example, you can use such a device in a bag or pocket.
BLUETOOTH standard is an international standard supported by thousands of companies all over the world, and employed by various companies worldwide.
Communication system and compatible BLUETOOTH profiles of the unit
Profile is standardization of the function for each BLUETOOTH device specification. The unit supports the following BLUETOOTH version and profiles:
Communication system:
BLUETOOTH Specification Ver. 3.0
Compatible BLUETOOTH profiles:
- A2DP (Advanced Audio Distribution Profile): Transmitting or receiving audio content of high-quality.
- AVRCP (Audio Video Remote Control Profile): Controlling A/V equipment; pausing, stopping, starting playback, etc.
- HSP (Headset Profile)(*): Talking on the phone/Operating the phone.
- HFP (Hands-free Profile)(*): Talking on the phone/Operating the phone by hands-free.
Maximum communication range
Use the devices within a range of about 10 m (30 feet) of line of sight.
Maximum communication range may shorten under the following conditions.
- There is an obstacle such as a person, metal, or wall between this unit and the BLUETOOTH device.
- A Wi-Fi device is in use near this unit.
- A microwave oven is in use near this unit.
- A device that generates electromagnetic radiation is in use near this unit.
Interference from other devices
Because BLUETOOTH devices and Wi-Fi (IEEE802.11b/g) use the same frequency, microwave interference may occur and resulting in communication speed deterioration, noise, or invalid connection if this unit is used near a Wi-Fi device. In such a case, perform the following.
- Use this unit at least 10 m (30 feet) away from the Wi-Fi device.
- If this unit is used within 10 m (30 feet) of a Wi-Fi device, turn off the Wi-Fi device.
Interference to other devices
Microwaves emitting from a BLUETOOTH device may affect the operation of electronic medical devices. Turn off this unit and other BLUETOOTH devices in the following locations, as it may cause an accident.
- where inflammable gas is present, in a hospital, train, airplane, or a gas station
- near automatic doors or a fire alarm
Note
- To be able to use the BLUETOOTH function, the BLUETOOTH device to be connected requires the same profile as this unit. Note also that even if the same profile exists, devices may vary in function depending on their specifications.
- Due to the characteristic of BLUETOOTH wireless technology, the sound played on this unit is slightly delayed from the sound played on the BLUETOOTH device during talking on the telephone or listening to the music.
- This unit supports security capabilities that comply with the BLUETOOTH standard to provide a secure connection when the BLUETOOTH wireless technology is used, but security may not be enough depending on the setting. Be careful when communicating using BLUETOOTH wireless technology.
- We do not take any responsibility for the leakage of information during BLUETOOTH communication.
- A device featuring the BLUETOOTH function is required to conform to the BLUETOOTH standard specified by Bluetooth SIG, Inc. and be authenticated. Even if the connected device conforms to the above mentioned BLUETOOTH standard, some devices may not be connected or work correctly, depending on the features or specifications of the device.
- Noise or sound skips may occur depending on the BLUETOOTH device connected with this unit, the communication environment or the usage environment.
Bluetooth wireless technology is a short range communications technology intended to replace the cables connecting portable unit and maintaining high levels of security. Bluetooth technology is based on Ad-hoc technology also known as Ad-hoc Pico nets, which is a local area network with a very limited coverage.
History of Bluetooth
WLAN technology enables device connectivity to infrastructure based services through a wireless carrier provider. The need for personal devices to communicate wirelessly with one another without an established infrastructure has led to the emergence of Personal Area Networks (PANs).
Ericsson's Bluetooth project in 1994 defines the standard for PANs to enable communication between mobile phones using low power and low cost radio interfaces.
In May 1988, Companies such as IBM, Intel, Nokia and Toshiba joined Ericsson to form the Bluetooth Special Interest Group (SIG) whose aim was to develop a defacto standard for PANs.
IEEE has approved a Bluetooth based standard named IEEE 802.15.1 for Wireless Personal Area Networks (WPANs). IEEE standard covers MAC and Physical layer applications.
Bluetooth specification details the entire protocol stack. Bluetooth employs Radio Frequency (RF) for communication. It makes use of frequency modulation to generate radio waves in the ISM band.
The usage of Bluetooth has widely increased for its special features.
Bluetooth offers a uniform structure for a wide range of devices to connect and communicate with each other.
Bluetooth technology has achieved global acceptance such that any Bluetooth enabled device, almost everywhere in the world, can be connected with Bluetooth enabled devices.
Low power consumption of Bluetooth technology and an offered range of up to ten meters has paved the way for several usage models.
Bluetooth offers interactive conference by establishing an adhoc network of laptops.
Bluetooth usage model includes cordless computer, intercom, cordless phone and mobile phones.
Piconets and Scatternets
Bluetooth enabled electronic devices connect and communicate wirelessly through shortrange devices known as Piconets. Bluetooth devices exist in small ad-hoc configurations with the ability to act either as master or slave the specification allows a mechanism for master and slave to switch their roles. Point to point configuration with one master and one slave is the simplest configuration.
When more than two Bluetooth devices communicate with one another, this is called a PICONET. A Piconet can contain up to seven slaves clustered around a single master. The device that initializes establishment of the Piconet becomes the master.
The master is responsible for transmission control by dividing the network into a series of time slots amongst the network members, as a part of time division multiplexing scheme which is shown below.
The features of Piconets are as follows −
Within a Piconet, the timing of various devices and the frequency hopping sequence of individual devices is determined by the clock and unique 48-bit address of master.
Each device can communicate simultaneously with up to seven other devices within a single Piconet.
Each device can communicate with several piconets simultaneously.
Piconets are established dynamically and automatically as Bluetooth enabled devices enter and leave piconets.
There is no direct connection between the slaves and all the connections are essentially master-to-slave or slave-to-master.
Slaves are allowed to transmit once these have been polled by the master.
Transmission starts in the slave-to-master time slot immediately following a polling packet from the master.
A device can be a member of two or more piconets, jumping from one piconet to another by adjusting the transmission regime-timing and frequency hopping sequence dictated by the master device of the second piconet.
It can be a slave in one piconet and master in another. It however cannot be a master in more than once piconet.
Devices resident in adjacent piconets provide a bridge to support inner-piconet connections, allowing assemblies of linked piconets to form a physically extensible communication infrastructure known as Scatternet.
Spectrum
Bluetooth technology operates in the unlicensed industrial, scientific and medical (ISM) band at 2.4 to 2.485 GHZ, using a spread spectrum 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.
Range
Bluetooth operating range depends on the device Class 3 radios have a range of up to 1 meter or 3 feet Class 2 radios are most commonly found in mobile devices have a range of 10 meters or 30 feet Class 1 radios are used primarily in industrial use cases have a range of 100 meters or 300 feet.
Data rate
Bluetooth supports 1Mbps data rate for version 1.2 and 3Mbps data rate for Version 2.0 combined with Error Data Rate.