Bluetooth technology

BLUETOOTH TECHNOLOGY

Introduction

Bluetooth is a specification for Wireless Personal Area. It is a way to connect and exchange information and data between mobile phones, laptops, digital cameras and video games. The communication is wireless and has the range of up to 10 meters.

The Bluetooth can connect with another Bluetooth. The data need not be carried on a CD or any other way it can be transferred by using a wireless method.

The Bluetooth enables to surf the net or check the emails on phones as travel. It is good for people who are always on the move and would like to keep checking their emails.

Bluetooth will also enables to transfer files, photos, and songs from the mobile to other device. The Bluetooth comes in with a wireless headsets and it comes in free with the mobile phone or computer, the wireless headset also useful for people who like to be on the go or while driving the car, as they are hands free.

The Bluetooth can be attached to  GPS system for navigation on mobile phones or laptops for making travel easy.

Some of the Most Common Bluetooth Products

Now-a-days Bluetooth technology has become the standard when talking about connecting various devices with each other, allowing tasks like data transfer to successfully work out, wirelessly.

             Poetically named after King Harald Bluetooth of Denmark and Norway, Bluetooth technology unites all sorts of products through the utilization of low power radio signals, on a 2.45 gigahertz frequency, which is actually between 2.402 gigahertz and 2.480 gigahertz radio frequency band. King Harald, whose reign came in the late tenth century, is quite famous for uniting the warring tribes of Denmark during his time as King, defining the poetic nature of the Bluetooth name.
           

With the ever rising popularity of Bluetooth technology, caused by its impressive universality as a means for devices  to  connect  with  each other and its

wireless nature, it really isn’t a wonder why many Bluetooth products abound the electronic device market.

Here are two of the most popular, and most common, of Bluetooth products available for one and all.

          These Bluetooth products could be easily defined as the wireless class of the hands free kits, which comes in packaged with most mobile phone brands. Hands free kits for mobile phones allow mobile phone users to take calls without having to physically put the phone to ones ear, giving users the ability to do other things while talking.
       

  As with all Bluetooth products, Bluetooth Headsets for Mobile Phones are wireless and could be easily connected with ones bluetooth enabled mobile phone, easy as one, two and three. This selfsame wireless nature makes Bluetooth Headsets for mobile phones convenient hands free kits, outperforming them in this aspect.

 Bluetooth Headsets for Mobile Phones are among the most popular of bluetooth products simply because they are great accessories to have, complementary to Mobile phones, which are items most persons have, these days. And they are wireless too.

         
          As Bluetooth products, Bluetooth Dongles or Bluetooth Adapters give personal computers which dont come with integrated Bluetooth capabilities the chance to connect with other Bluetooth items. They are basically Bluetooth products which work in conjunction with a computer program, giving non-Bluetooth computers the avenue for Bluetooth connections.

Because of their appearance, Bluetooth Dongles or Bluetooth Adapters are often mistaken for USB Portable Flash Disks, which are basically popular portable storage devices used by many. They do not, in any way, work as Flash Disks, but rather boast same physical appearance as items.

 I
t has two most popular Bluetooth products out in the market today. There are actually more Bluetooth products out there. These two simply represent the most top selling of Bluetooth products, which stands testament to the importance of Bluetooth technology in gadgets today.

How Bluetooth Works

            Bluetooth devices will normally operate at 2.4 GHZ in the license free, globally available Industrial Scientific and Medical (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, and the devices (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 security as it's very hard for an eavesdropping device to predict which frequency the Bluetooth devices 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.

Technical Overview of Bluetooth Technology

          Bluetooth wireless technology is an open specification for a wireless personal area network (PAN). It provides limited range wireless connectivity for voice and data transmissions between information appliances. Bluetooth wireless technology eliminates the need for interconnecting cables. Unique for most wireless communications systems, Bluetooth enables ad hoc networking among devices, without the need for infrastructure such as base stations or access points.

          Bluetooth, in its most elementary form, is defined as a global specification for wireless connectivity. Because it is intended to replace cables, cost must be low and operation must be intuitive and robust. These requirements for Bluetooth create many challenges. Bluetooth meets these challenges by several means. The radio unit employs frequency hopping spread spectrum (FHSS), and the design emphasis is on very low power, extremely low cost, and robust operation in the uncoordinated, interference-dominated RF environment of the industrial, scientific, and medical (ISM) radio band.

          A wide variety of Bluetooth radio block diagrams are in use. For transmission, these range from direct voltage controlled oscillator (VCO) modulation to IQ mixing at the final radio frequency (RF.) In the receiver, a conventional frequency discriminator or IQ down-conversion combined with analog-to-digital conversion is noted.

          While many options can satisfy the Bluetooth radio specifications, each will have its own characteristics if not operating correctly. The Bluetooth system consists of a radio unit, a baseband link control unit, and link management software. It also includes higher-level software utilities that focus on interoperability features and functionality.

        The above Figure is a block diagram for this type of frequency hopping system, showing the baseband controller and the RF transmitter and receiver sections. EDR is an enhancement to the Bluetooth 1.2 standard and is described in the Bluetooth 2.0 specification. It is backward compatible with the earlier Bluetooth standards. It uses a phase shift keying (PSK) modulation scheme to achieve a data rate of 2 or 3 Mb/s. It allows greater possibilities for using multiple devices on the same connection because of the increased bandwidth. Due to EDR having a reduced duty cycle, there is lower power consumption compared to a standard Bluetooth link.

1.  Bluetooth Devices are Wireless.

          There are tons of advantages/benefits when using wireless devices. In addition to improving safety as a result of eliminating the clutter of wires and associated hazardous connections, wireless technology also offers many convenient advantages. For example, when traveling with the laptop, PDA, MP3 player and other devices, there is no worry about bringing   along  all  of  connecting  cables.

2.  Bluetooth Technology is Inexpensive.

          Bluetooth technology is cheap for companies to implement, which results in lower over-all manufacturing costs. These savings are then passed on to the consumer. The end result is Bluetooth devices are relatively inexpensive.

3.  Bluetooth is Automatic.

          Bluetooth doesn’t think about setting up a connection or to push any buttons. When two or more Bluetooth devices enter a range (Up to 30 feet) of one another, they automatically begin to communicate without having to do anything. Once the communication begins, Bluetooth devices will setup Personal Area Networks or Piconets. . 

4. Standardized Protocol / Interoperability

          Since Bluetooth is a standardized wireless specification, a high level of compatibility among devices is guaranteed. The Bluetooth specification uses and defines various profiles. Every Bluetooth profile is specific to a particular function. For instance, when a Bluetooth enabled cell phone and a Bluetooth headset (Both with the same profile) are communicating with one another, both will understand each other without the user having to do anything, even if the devices are of different models/makes.

5. Low Interference 

          Bluetooth devices avoid interference with other wireless devices by:

a) Using a technique known as spread-spectrum frequency hopping.

b) Using low power wireless signals.

6. Low Energy Consumption

          Bluetooth uses low power signals. As a result, the technology requires little energy and will therefore use less battery or electrical power. Obviously, this is a great benefit for mobile devices because Bluetooth won't drain the life of device's battery.

7. Share Voice and Data

          The Bluetooth standard allows compatible devices to share both voice and data communications. For example, it is probably no surprise that a Bluetooth enabled cell phone is capable of sharing voice communications with a compatible Bluetooth headset. Then, using Bluetooth the phone can connect to a laptop. At the end the laptop is capable of surfing the web or sending and receiving email.

8. Instant Personal Area Network (PAN)

          Up to seven compatible Bluetooth devices can connect to one another within approximity of up to 30 feet, forming a PAN or piconet. Multiple piconets can be automatically setup for a single room.

9. Upgradeable

The Bluetooth standard is upgradeable. A development group at the Bluetooth Special Interest Group (SIG) has been given the task of working on the new Bluetooth version 2, which offers several new advantages and is backward compatible with the older versions.