Bluetooth is a radio frequency (RF) specification for short-range, point-to-multipoint voice and data transfer. Bluetooth can transmit through solid, non-metal objects and its nominal link range is from 10 cm to 10 m, but can be extended to 100 m by increasing the transmit power. The Bluetooth wireless technology aims to provide a user or service provider with the convenience of mobility and convenient mobile services. Bluetooth is intended to offer fast and reliable short-range radio communication and service convenience to business users. Bluetooth defines the optimized technical characteristics of portable computers and communication device models. Bluetooth devices are designed especially to provide low-cost, robust, efficient, high-rate transmission of both voice and data. The bluetooth technology partitions frequency bands to transmit data, and transmits frequency to the partitioned frequency bands as dividing the frequency. The bluetooth is also used for moving data from one channel to the other channel utilizing the above spectrum. Bluetooth is based on a low-cost, short-range radio link, and facilitates ad hoc connections for stationary and mobile communication environments. Bluetooth units sharing the same channel form a piconet with one unit acting as a master and the other units acting as slaves. The master transmits voice and/or data and the slaves receive voice and/or data. A radio link is connected between bluetooth-compatible communication terminals. Between a mobile terminal and a wireless headset, for example, a radio link is connected for transmission of voice or data upon call origination/termination. The main body requesting link connection, the master is the mobile terminal and the slave is the wireless headset. The bluetooth base-band supports link level authentication. When authentication is enabled a PIN (personal identification number) code must be entered on both devices wanting to communicate before a connection (link) can be established. The bluetooth base-band also supports encryption. To enable encryption a PIN code must be entered on both devices wanting to communicate. The PIN code is used to create the key for the encryption.

Bluetooth allows direct radio communication among devices without passing through a remote base station so that data can be freely transmitted at high speeds without any standby time, while causing no communication load to the base station. The bluetooth technology not only eliminates the need for wires, cables and connectors between various electronic devices, it also paves the way for new and completely different devices and communications networks. Generally, computers and other electronic devices are interconnected via physical cables or wires. These communication paths allow for the exchange of data or control information between such devices. However, it is increasingly recognized that the elimination of cables and wires to interconnect devices provides advantages such as ease of configuration and reconfiguration. Furthermore, space that would ordinarily be used for device interconnection media may be given to other uses. The core of the bluetooth application is to make interface of a digital apparatus wireless. There are various applications based on the bluetooth technology. The bluetooth modules have been widely applied to communication terminals, computer peripherals, and household appliances, etc. The cellular phone application is basically an application of the bluetooth technology and takes the advantage of the bluetooth technology. The cellular phone application can be performed using an audio channel, which is the biggest advantage of the bluetooth technology. A wireless headset or an earphone is a representative example of the bluetooth module used in cell phone. A user is able to speak on the phone using the wireless headset when the cellular phone is in a bag or in a pocket, and the wireless headset can be used as a hands free device while the user drives a car. The bluetooth headset allows a user to hear a voice signal of a called party in the same way as a headphone, and meanwhile allows the user to transmit his or her voice signal to the called party in the same way as a microphone.

The headset communication system generally comprises a headset having a microphone and an earpiece. The microphone is positioned at the end of a boom extending from the headband. The microphone detects sounds, such as voice sounds, and produces a microphone output signal in response to the detected sounds. The microphone output signal may be provided to a plurality of output terminals and thereby communicated simultaneously to audio speakers used by a plurality of persons. Headsets have a headband passing over the user's head, with earphones at each end of the headband or an earphone and a temple pad at opposite ends of the headband. The headband typically consists of one single-rate leaf spring having only one unstressed width, but which is flexed to fit different sized heads. The electronics housing is typically attached to one end of the headband and usually includes an earphone speaker, a microphone boom, and the electronic circuitry necessary to operate the earphone and microphone. The headset is worn on the user's head in such a manner to enable the earpiece to comfortably be positioned over one of the user's ears and to position the microphone generally near the user's mouth. A cable connects the headset to a transceiver which is worn generally on the hips or waist of the user. The transceiver receives the wireless communication and converts it to an electrical signal which stimulates the earpiece to produce voice signal. A wireless headset includes a battery, a microphone, a speaker and an inner transceiver. A wireless headset also requires a second, external transceiver, which has its own battery. This external transceiver, commonly known as a "dongle," replaces the wire which would otherwise connect the headset with an external device. The dongle receives headset signals from the wireless headset and transmits the transformed headset signals to the external device. The dongle also receives device signals from the external device, transforms the device signals into a format used by the headset and transmits the transformed device signals to the headset.

Both wireless headsets and those having a wire can typically be categorized into one of three general categories: ear bud headsets, on-the-ear headsets and over-the-head headsets. The ear bud headset is a headset having a wire connection to the base unit. Ear bud headsets have the speaker encased in a soft, flexible, generally cylindrical casing that is designed to be positioned in the opening of the auditory canal of a user's ear and held in place by the pressure of the casing against portions of the ear. These types of headsets are often uncomfortable, easily dislodged from the ear and difficult to secure into the ear. They often require the use of two hands to secure the headset against the ear. On-the-ear headsets, ometimes referred to as over-the-ear headsets, are offered as one alternative to ear bud headsets. These headsets typically utilize speakers that rest on the ear in a position opposite the auditory canal, similar to the over-the-ear headsets, but have a head band extending therefrom that wraps at least partially over the user's head. The speakers are generally held against the ear via an earpiece that extends from the speaker and wraps over and around the perimeter, or pinna, of the user's ear. These types of headsets, however, can be extremely difficult to secure onto a user's ear. Such headsets typically require the use of two hands to place the earpiece around the perimeter of the ear to secure the headset. Moreover, On-the-ear headset has poor acoustic coupling to the ear canal, a condition that requires a larger speaker and/or more power to drive the speaker to provide sufficient volume. The over-the-head headset, which allows hands-free operation, is commonly worn by telephone operators and is increasingly being worn by personal computer users for telephony over the internet, gaming, and speech recognition. But over-the-head headsets are generally more bulky than the other types of headsets and cover a larger surface area.