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How Bluetooth Works
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. The connected devices however, must agree upon the frequency they will use next. The specification in Bluetooth ensures this in two ways. First, it defines a master and slave type relationship between bluetooth devices. Next, it specifies an algorithm that uses device specific information when calculating the frequency hop sequences. A Bluetooth device that operates in master mode can communicate with up to seven devices that are set in slave mode. To each of the slaves, the master Bluetooth device will send its own unique address and the value of its own internal clock. The information sent is then used to calculate the frequency hop sequences. Because the master device and each of the slave devices use the same algorithm with the same initial input, the connected devices will always arrive together at the next frequency that they have agreed upon. As a replacement for cable technology, it's no wonder that Bluetooth devices are usually battery powered, such as wireless mice and battery powered cell phones. To conserve the power, most devices operate in low power. This helps to give Bluetooth devices a range of around 5 - 10 meters. This range is far enough for wireless communication but close enough to avoid drawing too much power from the power source of the device.
Bluetooth In Action |
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10 Benefits Of Bluetooth Below, are 10 benefits and reasons to use Bluetooth technology. 1. Wireless As you probably already know, there are many benefits and advantages to using wireless devices. Along with improving safety as a result of eliminating wires ... 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... Bluetooth Applications With Bluetooth being very popular with wireless, it's no wonder there are many applications available for the technology. Below, you'll find the applications for Bluetooth. 1. Wireless networking between laptops and desktop ... Bluetooth Basics The technology of Bluetooth wireless is a short range communications method intended to replace the cables that connect portable or fixed devices while maintaining the highest levels of security. The key features offered by Bluetooth... Bluetooth In Action In the United States, Bluetooth gets absolutely no respect. It is however, becoming more and more common in notebooks, PDAs, and especially cell phones. Bluetooth will provide wireless users a way to transmit small amounts of data over... 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... 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... Connecting Many With Bluetooth Constantly evolving, the technology of Bluetooth started off as a basic wireless connection standard but has since then been adapted and proven with many different uses and functions. A good example is Bluetooth for cell phones. It ... Key Learning Points Of Bluetooth Bluetooth is easily the best in wireless handheld technology. When it comes to learning, Bluetooth can get quite complicated. To help you, you'll find the key learning points of Bluetooth below: 1. Bluetooth is an energy efficient,... The Future Of Bluetooth Because it meets the basic needs of connectivity in close range, Bluetooth has a very bright future ahead of it. Bluetooth is actually the result of initiatives from nine leading communications and computer industry giants, including...
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