INTRODUCTION:

Bluetooth is an open standard for wireless connectivity with supporters mostly from the PC and cell phone industries In the year 1994, the company of telecommunications ERICSSON, began a study to investigate the viability of a radio low cost interface between mobile telephones and the accessories. The objective was to eliminate the cables between the mobile telephones and cards of PCs, headsets, desktop devices, etc. The motive was simple: to eliminate the need for proprietary cable connections between devices. In February, 1998, the Bluetooth Special Interest Group is formed which is an industry group, comprised of leaders in the telecommunications and computing industries. The members of this group were Ericsson, Nokia, IBM, Toshiba and Intel, Which is the perfect mixture in the business area: two leaders of the market in mobile telephony, two leaders of the market in computers laptop and a leader of the market in technology of processing of digital signs.

The goal of this was to establish the creation of a global specification for connectivity without wires of short scope. 20 and 21 of May, 1998, Bluetooth's consortium was announced to the general public of London (England), San Jose (California) and Tokyo (Japan). That global announcement provokes the adoption of the technology for several companies. The intention of the consortium was to establish a standard device and software that controls it.

WHAT IS BLUETOOTH:

Bluetooth is a wireless technology standard for exchanging data over short distances from fixed and mobile devices, and building personal area networks. It can be used at home, in the office, in the car, etc. This technology allows to the users instantaneous connections of voice and information between several devices in real time. It is a small microchip that operates in a band of available frequency throughout the world. Communications can realize point to point and point multipoint. Its main characteristics include: low complexity, low consume, hardiness and low cost.

THE LOGO OF BLUETOOTH:

As famous as the name is the Bluetooth symbol. Everybody can recognize this symbol like the Bluetooth icon, but again few of them knows the origin. Bluetooth's logo combines the representation of the Nordic runes Hagalaz (transcribed by 'H') and Berkana (transcribed by 'B') in the same symbol. This is, HB like Harald Blåtand the king:

Bluetooth working:

The technical details of Bluetooth´s function are very complex, Bluetooth uses frequency hopping in timeslots. Bluetooth has been designed to operate in noisy radio frequency environments, or and uses a fast acknowledgement and a frequency-hopping scheme to make the communications link robust, communication-wise. The Bluetooth radio is built into a small microchip and operates in a globally available frequency band ensuring communication compatibility worldwide. The Bluetooth specification has two power levels defined;

· A lower power level that covers the shorter personal area within a room, and

· A higher power level that can cover a medium range such as within a home.

Software controls and identity coding built into each microchip ensure that only those units preset by their owners can communicate.

Bluetooth Network Topology:

The Bluetooth technology provides both a point-to-point connection and a point-to-multipoint connection. In point-to-multipoint connections, the channel is shared among several Bluetooth units. In point-to-point connections, only two units share the connection. If several piconets overlap a physical area, and members of the various piconets communicate with each other, this new, larger network is known as a scatternet. Multiple Bluetooth units form a Wireless Personal Area Network, called a piconet. A piconet consists of one hub device and up to seven client devices. It is possible to support more devices in a piconet by placing one or more of the clients into what is referred to as park mode. In order to exchange information with the parked client, the hub must take it out of parked mode and return it to active mode. Only seven clients can be in active mode at any given time. When two piconets are in close proximity, they have overlapping coverage areas - a scenario referred to as a scatternet Clients in one piconet can participate in another piconet as either a hub or client. This is accomplished through time division on multiplexing. In a scatternet, the two (or more) piconets are not synchronized in either time or frequency. Each of the piconets operates in its own frequency-hopping channel, while any devices in multiple piconets participate at the appropriate time via time division multiplexing. A piconet can be created in one of 4 ways: A page (used by Master to connect to Slave) or A page scan (a unit listens for its´ device access code) or A Master – Slave switch is made An ”Unpark” of a unit is made (provided there are no active slaves).

Bluetooth security:

The Bluetooth system is intended to be used as a uniform interface to all of a person's information sources and will thus be expected to transfer sensitive personal data. Security of the data is thus an important issue. Bluetooth devices are expected to be omnipresent and at some places the access to these devices by public users may have to be restricted. This calls for authentication procedures to be provided. The scheme used by the Bluetooth standard to tackle these issues is referred to as the challenge response scheme. The application may itself encrypt its data for added security that can add to the safety of the data, but the most of the authentication is based on the link level security procedures.

Bluetooth Security Recommendations & Precautions

1. Never use standard commercial Bluetooth headsets.

2. Enable Bluetooth functionality only when necessary.

3. Require and use only devices with low-power Class 2 or 3 Bluetooth transceivers.

4. Keep devices as close together as possible when Bluetooth links are active.

5. Make devices discoverable (visible to other Bluetooth devices) only if/when absolutely necessary.

6. Make devices connectable (capable of accepting and completing incoming connection requests) only if/when absolutely necessary and only until the required connection is established.

7. Use device firewalls, regularly patch Bluetooth devices, and keep device anti-virus software up to date

How to set up Bluetooth connection:

Follow the following steps to connect Bluetooth devices:-

1. Ensure both of your devices have Bluetooth capability.

2. Charge the devices before attempting to connect a Bluetooth device, if necessary:- This is necessary with headsets, phones, game controllers and some computer accessories

3. Turn the devices on:- Put your primary device into pairing or set up mode. This is sometimes referred to as "Bonding Mode”. This can be done by opening the application and select the pairing, setup or bonding modes. Bluetooth may also be listed under your connections profile on your main menu. Turn the Bluetooth mode on by changing the settings on this menu.

4. Put the Bluetooth device into pairing or sync mode:- Try to activate both devices around the same time. They will search for each other for approximately 60 seconds. If you do not activate them within that time, it may say that no Bluetooth pairing devices were found and you should try again.

5. Select the device that you would like to pair on the primary device's screen:-It may list the model of the headset or controller. Press "OK," "Enter" or "Select."

· You may be asked to enter a PIN code. If so, your primary device will generate a code that will then be entered into the PIN section on your Bluetooth device. This will result in a secure connection.

· If you have not been given a pin code in the process, type "OOOO," which may be the default code.

Features of Bluetooth technology:

1. Bluetooth uses a short-range (10 meters) radio link. The range can be increased to about 100 meters with boosters, which increase the power of the signals.

2. The gross data rate is about 1 Mbps.

3. Bluetooth uses the unlicensed ISM (Industrial, Scientific and Medical) band (2.4 GHz). This makes Bluetooth-enabled products workable across the globe, eradicating compatibility issues.

4. It separates the frequency band into hops. This spread spectrum is used to hop from one channel to another, which adds a strong layer of security.

5. Signals can be transmitted through walls and briefcases, thus eliminating the need for line-of-sight. Devices do not need to be pointed at each other, as signals are Omni-directional.

6. Both synchronous and asynchronous applications are supported, making it easy to implement on a variety of devices and for a variety of services, such as voice and Internet.

7. The Aim of "Bluetooth" has been set quite high. It is to arrive at a specification for a technology that optimizes the usage model of all mobile computing and communications devices, and providing Global usage, Voice and data handling.

Applications of Bluetooth technology:

Bluetooth has a tremendous potential in moving and synchronizing information in a localized setting. Potential for Bluetooth applications is huge, because we transact business and communicate more with people who are close by than with those who are far away - a natural phenomenon of human interaction. The following list represents only a small set of potential applications

· Wireless networking between PCs in a confined space and where little bandwidth is required.

· Wireless communications with PC input and output devices, the most common being the mouse, keyboard and printer.

· Transfer of files between devices with OBEX (a kind of communications protocol).

· Replacement of traditional wired serial communications in test equipment, GPS receivers, medical equipment, bar code scanners, and traffic control devices.

· Sending small advertisements from Bluetooth enabled advertising hoardings to other, discoverable, Bluetooth devices.

CONCLUSION:

In the future, Bluetooth is likely to be standard in tens of millions of mobile phones, PCs, laptops, and a whole range of other electronic devices. As a result, the market is going to demand new innovative applications, value added services, end-to-end solutions, and much more. The possibilities opened up really are limitless, and because the radio frequency used is globally available, Bluetooth can offer fast and secure access to wireless connectivity all over the world. With potential like that, it’s no wonder that Bluetooth is set to become the fastest adopted technology in history.

REFERENCES:

[1] Pravin Bhagwat, “Bluetooth: Technology for Short-Range Wireless Apps”

[2] S. Rama Reddy, “Bluetooth in Wireless Communication “

[3] Eduard Heindl, “Bluetooth”.

[4]San Jose, “Bluetooth Technology Overview” .

Received on 22.03.2014 Accepted on 31.03.2014

Research J. Engineering and Tech. 5(1): Jan.-Mar. 2014 page 42-44