BLUE TOOTH

INTRODUCTION:

                   Wireless LANs are the hot new enterprise technology that every one is talking about and considering implementing in varying degrees for vertical markets like medical, education and manufacturing.

                  

                   Before delving straight into the details of wireless LAN standards let’s take a look at technologies that make it possible for a wireless LAN to operate.  These technologies are

·        Radio frequency systems

·        Infrared systems

·        Spread spectrum implementation

·        Frequency Hopping Speed Spectrum

·        Direct Sequence Speed Spectrum

        Some of the wireless standards now available in the market are

                  

·        IEEE 802.11

·        HIPER LAN2

·        BLUE TOOTH

·        HOME RF

How Blue Tooth came into existence?:

                   We may heard of  WPANS  (Wireless personal area networks)

                                                  WLANS (Wireless local area networks)

                                               WWANS (Wireless wide area networks)

Flexibility and mobility make wireless LANs an attractive alternative to wired networks.

                   Wireless LANs provide all the functionality of wired LANs with out physical constraints of the wire itself.

          The above mentioned three types of networks differentiate in range, data rates, power consumption and cost.

          WLANS are 802.11b wireless Ethernet with higher speeds and longer ranges used in office buildings and homes.

          WWANS such as cellular Networks, work over a large area but less lower data rates.

          WPANS such as Blue Tooth Piconets, provide short-range connectivity for devices such as laptops, PDAS, cellular phones and even PCs in a network with small geographical spread and support low data rates and limited ranges to achieve low cost and minimum power drain.

Definition to Blue Tooth:

                   It is a two-year old Technology, which is a short-range radio Technology that allows wireless data transmission between various computing and communication devices up to a distance of 10meters or 30feet and offers data transfer rates up to 1MBPS.

                   It is named after HAROLD BLUETOOTH a 10century Danish king who united Norway and Denmark with a short-range radio technology that allows voice and data.

A WALK ON TO THE BLUE SIDE:

          Product Scene:-

1.     Blue Tooth sooner or later is going to go in the WAP way ,reason for this is that it has been over two year plus and there are hardly any blue tooth products available in the market

2.     Some of the Blue tooth products available in the market are Cell phones, Laptops, PDAs, Network cards and so on.

3.     But it does not imply that the technology is a success.

4.     If any new technology came into market it first attracts niche user base of technology and Gizmo enthusiasts.

5.     It has to survive for two-to-three years in the market place before it gains mass acceptance.

6.     Many Industries are contributing to the Blue tooth SIG (Special Interest Group).

HOW IT WORKS:-

                   Blue tooth uses the FHSS (Frequency Hopping Spread Spectrum) protocol as wireless LAN standard. Spread spectrum technology is a wide band radio frequency technique developed by the military for use in reliable, secure, mission-critical communication system. Spread-spectrum is designed to trade off bandwidth efficiency for reliability, integrity and security.

                   Frequency Hopping spread spectrum (FHSS) uses a narrow band carrier that changes frequency in a pattern know to both transmitter and receiver.

FHSS appears to be short-duration impulse noise radios in Blue tooth can be master or slave or be in simultaneous scenarios.

          Two possible Bluetooth networks available

                                     

·        PICONET

·        SCATTERNET

PICONET:

        When we bring Blue tooth radios with in the range of each other they connect and form a piconet. one becomes master and other a slave .The master controls all the traffic in a piconet . Blue tooth radios in a piconet frequency hop together. Each piconet can have up to seven simultaneous or more than 200 active slaves.

                   Radio in the piconet can be in one of five states

                                     

·        Stand BY

·        Inquire

·        Page

·        Connect

·        Park/Hold

Ø Stand by is radio waiting to join a piconet.

Ø Inquire is a radio seeking other radio to connect.

Ø Page is a master radio asking to connect to a specific radio.

Ø Connect is a radio active on a piconet as a master-slave or simultaneous.

Ø Park/Hold is a low power connected state.

                   The master gives all the slaves in a piconet its clock-device ID and sets the unique hopping sequence based on the master device address.

SCATTERNETS:

                      Scatter nets occur when multiple masters exist in range of each other.  A master radio may also be a slave radio on another piconet.

                   Each piconet is hopping with a different sequence sharing the same as 2.4GHz band.  Because of the different hopping sequences, there is very little chance that any master will hit a channel at the same time as another master.

Bluetooth Stack:

	APPLICATION
	JINI				WAP
	SDP		SDP				RFCOMMMMM
	L2CAP
	LINK MANAGER
	ACL								SCO
	BASE BAND
	BLUETOOTH RADIO

 

Bluetooth Radio:

                   Bluetooth Radio is Transceiver which transmits and receives modulated electrical signals from peer Bluetooth devices.  The radio for compatibility reasons should have some defined transmitter and receiver characteristics.

Baseband:

                   Baseband is the physical layer of Bluetooth that manages physical channels and links apart from other services like end correction, data whitening, hop selection and Bluetooth security.

ACL:

                   ACL is Asynchronous Connectionless physical link for Transmitting data over physical channels.  ACL link provides a packet switched connection between the master and all the active sales.

SCO:

                   SCO is Synchronous Connection Oriented physical for voice-like information.  It is a symmetric point-to-point link between the master and a specific slave.  It behaves like a circuit-switched connection.

Link Manager:

                   Essentially handles link set-up, security and control.  It provides services like autherification, encryption control, power control and provides QOS capabilities.  It also manages devices in different modes.

L2 Cap:

                   It is the logical link control and adoption layer protocol.  It resides in the data link layer and provides connectionless and connection-oriented data services to upper layer protocols with protocol multiplexing capability, segmentation and reassemble operation and group abstraction.

                   It permits higher-level protocols and applications to transmit and receive L2 cap data packets up to 64KB in length.

SDP:

                   It is Service Discovery Protocol for applications to discover which services are available and to determine the characteristics of these available services.

RFCOMM:

                   It is a Simple Transport Protocol.  It supports up to 60 simultaneous connections between two Bluetooth devices.

WHEN WILL IT TAKE OFF:

                   Blue Tooth wireless technology is the marriage of the telecom and computing industries, scans cables.

                   Blue Tooth is set to revolutionize the person connectivity market by providing freedom from wired connections.

                   The idea that triggered on this technology in the late 1990’s to eliminate the uses of cables altogether, enabling users to connect a wide range of computing and telecommunications devices easily and simply, without the need to buy, care or connect cables.

                   Primary advantage of Blue Tooth is its technology is that it uses the 2.46HZ Industrial, Scientific and Medical countries.

MARKET ACCEPTENCE:

                   Vendors are doing a lot of work for embedding Bluetooth as product, it just a trickle now.  It is expected to explode soon, the number of Blue tooth enabled devices is expected to reach 700 million by 2004.

                   Since it is introducing into the market for the last five-six months, It is just beginning to see the light of day.

Efforts are making to develop a new product around the Blue tooth stack in terms of user acceptance.

                   Bluetooth SIG comprising of industry hereby weights like IBM, NOKIA, Ericsson and 2000 other small and big companies.  To promote it to worldwide. Now SIG is working to secure the approval for the use of Bluetooth through out the world.

APPLICATION:

                  

·        These stacks can be embedded in mobile phones, palmtops, laptops, consumer   applications, medical equipment automobiles and so on.

·        It eliminates the need of cables.

·        Blue tooth applications are file transmit, data synchronization (Schedule, telephone book), data exchange (business cards etc) voice transmission (headset and cord less telephony), image transfer, LAN access (to Ethernet, Token Ring Fire Wire, USB…) and Dial-up networking (Internet/Intranet Bridge).

MERITS AND DEMERITS:

          Any upcoming technology has both merits and demerits, that is yet to reach maturity

         

1.     Merit that clearly stands out is “the ability of the Technology to take us into the wireless world with point-to-multi point connectivity to any device or into any existing application.

2.     Major Limitation is its speed and range.

3.     Advantage:-  Vendors can built it into their devices with a low cost to consumer.

4.     Is a win situation for the user.

5.     Logical solution for wireless connectivity

6.     Revolutionize the way business is done today.

7.     It exceeds the exceptions of those who are directly correlated with it.

8.     Its strength lies in the minimal hardware dimensions low priced components and the low power consumption.

DRAWBACK:-

1.     Lack of inter operability among various standards.

FUTURE PRODUCTS THAT WILL COME INTO THE MARKET:-

          Motorala India Electronics is introducing a product soon to be expected in the market is the Bluetooth radio which will operate on the globally available 2.45GHZ ISM “free band” allowing international travelers to use Bluetooth enabled equipment any where in the world.

COMPETITION:

       

      COMPARISION OF BLUETOOTH WITH 802.11:

                       Debate is going on whether Blue tooth competes with 802.11(Wireless LAN). Both are similar and are used for WLANS and operate in the unregulated 2.4GHZ frequency space. but 802.11 transmits data bout 15 times faster and that to over longer distances as compared to Blue tooth put this wants at an inflated cost and higher power consumption but Blue tooth is of low cost and low power consumption is ideal for cellular phones, handheld, laptops.

SPECIFICATION COMPARISON OF BLUE TOOTH WITH IrDA, HOME RF

SPECIFICATION	BLUE TOOTH	IrDA	HOME RF
Data Rate(kbps)	1000	4000	2000
Distance(m)	10	1	50
No.of Devices	8	2	127
Voice Channels	3	1	6
Topology	Point to multi point	Point to Point	Network

COMPLEXITY KEEPS GROWING:

                   Single Interference, cost and standards obstacles, and on top of this, every one has a competing Technology from Bluetooth, Home RF, and phone line networking, to SUN’S JINI. This type of innovation and company promoted consortiums and standards are as usual creating hindrance in both their adoption and use.

CONCLUSION:

                   We can conclude that Blue Tooth is an emerging technology. Even though it is a emerging technology blue tooth has to receive the over whelming support of all digital and computer equipment manufactures to become a basic unit in the production process.

 

 Reference BOOKS:

                   NETWORK MAGAZINE --- JUNE 2001

                   NETWORK MAGAZINE --- MARCH 2001