BLUETOOTHBASED WIRELESS

SENSOR NETWORKS

Contents Introduction Blutooth Specification Blutooth Basics Blutooth Topology Blutooth Software Blutooth Keyboard Blutooth Protocol Stack Blutooth Security Blutooth Based Sensor N/W Sensor N/W Implementation Blutooth Hardware

Architecture Algorithms For Operation Of

Networks Merits Demerits

Introduction Bluetooth Wireless Technology (BWT) was developed in

1994 at Ericsson in Sweden. It is named for Harald Blaatand. Bluetooth-Wireless and Automatic technology simplifying

art of communication. Frequency used is 2.45 GHz, same used in ISM devices. Purpose – Originally it was build to eliminate the need for

cable connections between PDAs and notebook PCs. Later the goals were to enable different devices through a commonly accepted standard for wireless connectivity . Ericsson on advent of BWT conceptualized a Radio Technology through a wireless personal area network (WPAN).

Bluetooth Specification

Bluetooth-Wireless technology providing link between mobile and electronic devices.

It operates on 2.45 GHz radio signals using frequency hopping spread spectrum.

Technology of Bluetooth concentrates on short range of communication.

Bluetooth Specification

•Standard: IEEE 802.15•ISM Band Frequency: 2.4 GHz•Range: 10 – 100 meters•Channel Bandwidth: 1 Mbps•Maximum Asymmetric Data Transfer

Rate: 721 Kbps

Types of Bluetooth Wireless Technology

Depending on the power consumption and range of the device, there are 3 Bluetooth Classes as:

•Class 1: Max Power – 100mW ; Range – 100 m

•Class 2: Max Power – 2.5mW ; Range – 10 m•Class 3: Max Power – 1mW ; Range – 1 m

Why the name Bluetooth?

The name was adopted as a tribute to the tenth-century vikingking Harald Blatand who peacefully united Denmark and Norway.

Harald liked to eat blueberries,which gave his teeth the coloration

that lead to the nickname "Bluetooth."

How to reduce interference?

•BWT devices hop randomly between frequencies up to 1600 times per second.

•So,if another device using a 2.4 GHz frequency (e.g.:cordless phone) ,

then the interference with the BWT network lasts only for about 1/1600 of a second.

•By then, the devices hop to another frequency.

.

Applications

Laptops PDA’s Headphones Wireless printer

adapter Onboard Bluetooth

adapter.

Bluetooth Basics

Bluetooth is low powered and low cost. All the devices follow a uniform structure Devices Connect through network called

Pico nets. Strength lies in handling data and video

transmission simultaneously.

Bluetooth Basics

Specification- Bluetooth specification gives developers data link and application layer definitions

Spectrum-Bluetooth operates between 2.4 and 2.485 GHz using a frequency hopping spread spectrum.

Interference- is reduced using Adaptive Frequency Hopping allowing a better efficiency and greater performance.

Bluetooth Topology

2 main topologies are as:

i.PICONET TOPOLOGY, & ii.SCATTERNET TOPOLOGY

i.Piconet Topology

•A piconet consists of upto 8 BWT-enabled devices.

•When piconet is established, one device sets up frequency-hopping pattern and other devices synchronize their signals to the same pattern.

•Each piconet has a different frequency-hopping pattern.

Piconet Topology

ii.Scatternet Topology•Scatternet consists of several piconets

connected by devices participating in multiple piconet.

• There is a ‘BRIDGE’ connecting 2 piconets which is also a slave in individual piconets.

Advantages of Scatternet :•Higher throughput•Multi-hop connections between

devices indifferent piconets

Network Topologies?

Bus Network

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Tree Network

Star Network

Ring Network

Ad Hoc Network

There are SO many technical questions: such as…

Future Of Bluetooth

•BROADCAST CHANNELS:Adoption of Bluetooth into mobile phones and enable advertising models based on users pulling information from the information points.

•TOPOLOGY MANAGEMENT:Automatic configuration of piconet topologies in scatternet situations.

Bluetooth Software

Bluetooth software can be installed and used on Bluetooth capable devices.

There exists different software for different devices like PDA , personal computer.

Enables the device to use technology at its fullest.

Best example is Bluesoleil.

Bluetooth software Bluesoleil can be installed on

personal computer or on

personal digital assistant also

On a PC, it provides a lot of Extra wireless features.

It also has a graphical user interface (GUI).

On a PDA, provides basic

Bluetooth profiles such as headset and hands free profile, personal networking (PAN) profile

How Bluetooth works? They normally operate at 2.45GHZ in license free globally available ISM radio band. Advantage-worldwide availability and compatibility. Disadvantage- devices must share the band with other RF emitters including automobile security systems, noise sources such as Microwaves Solution- Frequency Hopping Spread Spectrum.

Frequency Hopping Spread Spectrum (FHSS)

Frequency hopping is jumping from one frequency to another within the ISM radio band.

Efficient use of entire bandwidth.

Low Interference

Provides basic level of security.

Working of FHSS

There exists a master-slave relation between devices.

A device in master mode can communicate with upto seven slave devices.

Bluetooth devices work in a short range to

conserve the battery power.

Technical operations

High speed, low powered wireless technology. Circuits are Contained on a 0.9 cm square. This offers 1MB link with security. Each device offers unique 48 bit address from

IEEE 802.15 standard. Authentification is via a 128 bit key. Supports up to 721KBps along with 3 voice

channels.

Bluetooth Keyboard Bluetooth keyboard is one of major applications of

Bluetooth technology. It was first developed by Microsoft in 2002. Today most of companies offer this type of

keyboard, some of which companies include Dell, Apple..

A Bluetooth keyboard and mouse combination will allow the user to work at distances of up to 30 feet.

There are mainly two types in this-wireless keyboard and virtual keyboard.

Wireless and Virtual keyboard Wireless keyboard, called

Optical Desktop Elite offered by Microsoft work with 2.4 GHz Bluetooth technology.

Apple wireless keyboard is a sleek and compact design and makes a secure, reliable connection with Mac.

Foldable types are another type of Bluetooth keyboards.

It ranges in full size keyboard to mini keyboard.

Virtual keyboard Virtual keyboard is projected

on a flat, non reflective surface and keystrokes are accompanied by key clicking sounds that are simulated.

The keyboard has 63 keys and it measures only 295*95 mm with a height of 3.5 inches.

Keyboard works by producing a red diode laser light when keyboard is projected on surface.

Potential Bluetooth Markets

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Bluetooth Market Forecast

29Nov’03: 100M Bluetooth compliant devices worldwide

Bluetooth Protocol Stack Adopted Protocols

• PPP(Point-To-Point Protocol)• TCP/UDP/IP• OBEX-Session Protocol for IrDA(Infrared Data

Association)• Contents Fromat(e.g. vCard, vCalendar)• WAP-Wireless Application Protocol

Bluetooth Security Supports Unidirectional or Mutual Encryption based

on a Secret Link key Shared Between Two Devices Security Defined In 3 modes:

• Mode1- No Security• Mode 2 - Service Level Security: Not Established

Before Channel is Established at L2CAP• Mode 3 - Link Level Security: Device Initiates

Security Before LMP Link is Setup

Bluetooth Security 3 Levels of Service Access

• Require Authorization and Authenication• Require Authentication Only• Default Security for Legacy Applications

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Bluetooth Based Sensor Networks

•One such application is : WIRELESS SENSOR NETWORKS (WSN)

•Important features of WSN:Collaboration of network nodes during execution and Data Centric nature.

•Many smart sensor nodes scattered in the field collect data and send it to users via ‘gateway’ using multi-hop routes.

Wireless Sensor Networks (WSN)

WSN consists of number of small devices equipped with asensing unit, microprocessors, wireless communication interfaceand power source.

Sensor Network Implementation

•OBJECTIVE: To build a Hardware platform and generic Software Solutions to serve for research in WSN protocols.

•Components of Sensor Network: Smart Sensor Nodes and Gateway

Example: Pressure SensorFor implementation of Pressure Sensor

as Bluetooth Node, following components are important:

•Bluetooth Device•Sensors•Microcontroller

Blutooth Hardware Architecture

Bluetooth Hardware consists of 3 main functional modules:

•2.4 GHz Bluetooth RF Transceiver Unit•Link Management Unit•Host Controller Interface

Industrial CyberSecurity

The Case of Vitek Boden

On October 31, 2001 Vitek Boden was convicted of:• 26 counts of will fully using a restricted computer to

cause damage• 1 count of causing serious environment harm

The facts of the case:• Vitek worked for the contractor involved in the

installation of Maroochy Shire sewage treatment plant.

• Vitek left the contractor in December 1999 and approached the shire for employment. He was refused.

• Between Jan 2000 and Apr 2000 the sewage system experienced 47 unexplainable faults, causing millions of liters of sewage to be spilled.

How did he do it?

On April 23, 2000 Vitek was arrested with stolen radio equipment, controller programming software on a laptop and a fully operational controller.

Vitek is now in jail…

Disgruntled Contractor

PLC PLC

Sewage Plant

Rogue Radio

Algorithms For Operation Of Networks

•Initialization of gateway and Bluetooth Inquiry Procedure.

•Discovery of Bluetooth device and Checking of major and minor devices.

•Setting of parameters and assigning type of devices and sensors.

•Description by Service-Class Field.•Discarding of non-smart nodes.

•Else, service database of the discovered smart node is searched for sensor services.

•If no current sensor profile, then database is searched for serial port connection parameters.

•Lastly, Bluetooth link is established and data exchange with smart node starts.

Sensor Market: $11B in 2001Installation (wiring) costs:

>$100B

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Freedonia Group report on Sensors, April 2002

• Fragmented market platform opportunity

• Installation cost limits penetration

reducing installation cost increases market size

Slide courtesy of Rob Conant, Dust

Highly FragmentedSensor Market

Firewall Architectures

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The external router blocks attempts to use the underlying IP layer to break security (e.g. IP spoofing, source routing, packet fragments, etc) and forces all traffic to the proxy.

The proxy firewall handles potential security holes in the higher layer protocols.

The internal router blocks all traffic except to the proxy server.

Internal RouterInternet

External Router

Statistics on Types of Attacks

0 20 40 60 80 100 120

Theft of Propriety Info

Sabotage

Telecom Evesdropping

System Penetration

Insider Abuse of Net Access

Finacial Fraud

Virus

Unauthorized Insider Access

Telecom Fraud

Active Wiretap

Laptop Theft

Denial of Service

1997

1998

1999

2000

2001

2002

*Source: “2002 CSI/FBI Computer Crime and Security Survey” Computer Security Institute - www.gocsi.com/losses.

% of Respondents

There’s lot of “Wireless”

From cellphones to PDAs to WiFi to Satellite-based

Wireless LAN Standards

Merits Wireless Inexpensive Automatic Interoperability Low interference and energy consumption. Share voice and data Instant PAN Upgradeable Long lasting technology. Easy link establishment

Demerits Data rate and security More susceptible to Interception and

attack Less range Average Speed Short Life

Thank You