Bluetooth Technology

Category Archives: Bluetooth Technology

Advantages And Disadvantages

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.

Bluetooth And Apple

The new Apple powerbook G4 are among the first computers to offer Bluetooth technology 2.0+EDR. The 2.0+EDR technology, which still backwards compatible with 1.0, is up to three times faster than previous versions, offering maximum data rate transfers of up to 3 Mbps. Being the first company to certify a system with 2.0+EDR, Apple continues to make great use of the Bluetooth technology.

Full support

In addition to the powerbook G4 portables, there are other Bluetooth enabled computers available from Apple, including the iBook, iMac G5, eMac, and the Power Mac G5.

Making life easier

When you turn the Bluetooth feature on, your Mac can easily perform a file transfer or even a synchronization. From the Bluetooth selection menu, you can choose to either send a file or browse devices, quickly and easily. Or, you can click the sync button in iSync to update your cell phone or Palm OS handheld.

Bluetooth Glossary

Below, you’ll find a list of the most used terms in

Bluetooth technology. They can serve as a look up, or to help you learn more about Bluetooth terms in general.

2 in 1 handset

The situation where a subscriber’s handset is acting as a remote handset to a base unit that provides a network connection.

Third generation, referring to the next generation of digital phone technology.

802.11 WLAN

A wireless LAN specification defined by the IEEE.

Access code

Each base band packet will start with an access code, which can be one of 3 types – CAC, DAC, and IAC.

Bluetooth Profiles

The profile found in Bluetooth will describe how the technology is used. Profiles can be best described as vertical slices through the protocol stack. It will define options in each protocol that are mandatory for the profile.

The profile will also define the parameter ranges for each protocol. The concept of the profile is used to decrease the risk of interoperability problems between the different products. These profiles won’t normally define any additions to the Bluetooth specification, which is why you can add new profiles where you need them. The Bluetooth underlying technology is the same, only the specific method that it’s used is defined.

Bluetooth Specifications

Below, you’ll find several specifications for the well known Bluetooth:

1. Throughout the United States and even Europe, the range of frequency is 2,400 – 2,483.5 MHZ, with 79 1-Mhz RF (radio frequency) channels. The frequency range in Japan is 2,472 to 2,497 Mhz with 23 1-Mhz RF channels.

2. A data channel of Bluetooth randomly hops 1,600 times per second between the 79 RF channels.

3. Each Bluetooth channel is divided into time slots, with each one being 625 microseconds long.

4. A Bluetooth piconet has one master and up to seven slaves. The master will transmit in even time slots, while the slaves will transmit in odd time slots.

Choosing A Bluetooth Headset

Creating a good wireless headset for Bluetooth is actually difficult to do. The regular wired headsets are easy to design – with ranging styles.

Bluetooth headsets can never be as small or as light as wired headsets, simply because it needs to include the battery and extra functions. This extra size will impact how the headset mounts on or around your ears.

Comfort

There seems to be two main styles of headsets for Bluetooth. Some are held into place with a loop around the ear. These styles are normally more comfortable, although they may be less secure. The others are held in place by being jammed into your ear – and usually prove to be less comfortable.

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 use next.