Bluetooth based-smart-sensor-network
- 2. CONTENTSCONTENTS • Introduction • Bluetooth • Smart sensor network • Research issues • Communication with smart sensor nodes • Conclusion
- 3. INTRODUCTIONINTRODUCTION • Bluetooth is wireless high speed data transfer technology over a short range (10 - 100 meters). • Bluetooth Wireless Technology (BWT) was developed in 1994 at Ericsson in Sweden. • 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.
- 4. INTRODUCTION (contd.) • Group called Bluetooth Special Interest Group (SIG) was formed in 1998 to develop the standard of IEEE 802.15 • This specification standardized the Bluetooth technology worldwide.
- 5. BLUETOOTHBLUETOOTH • Bluetooth Specifications are: • Developed by: Jaap Haarsten and Sven Mattisson in Sweden • 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
- 6. BLUETOOTH TOPOLOGYBLUETOOTH TOPOLOGY Depending on the type of connections established between various Bluetooth devices, 2 main topologies are as: 1. PICONET TOPOLOGY, and 2. SCATTERNET TOPOLOGY • To any topology, there are 2 prime components: 1. MASTER device 2. SLAVE device
- 7. 1. PICONET TOPOLOGY1. 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. • Primary Devices: Those devices which sets the frequency- hopping pattern. • Secondary Devices: Those devices which get synchronized. • Each piconet has a different frequency-hopping pattern.
- 8. PICONET TOPOLOGY (contd.)PICONET TOPOLOGY (contd.)
- 9. PICONET TOPOLOGY (contd.)PICONET TOPOLOGY (contd.) • In Bluetooth, each piconet has 1 Master for establishment of piconet, and upto 7 Slave devices. • Master’s Bluetooth address is used for defining frequency- hopping sequence. • Slave devices use master clock to synchronize their clocks so as to hop simultaneously. • For establishing piconet, other bluetooth devices in range are discovered by an inquiry procedure.
- 10. 2. SCATTERNET TOPOLOGY2. SCATTERNET TOPOLOGY • Scatternet consists of several piconets connected by devices participating in multiple piconet. • Here, devices can be slaves in all piconets or master in one piconet and slave in other piconets. • There is a ‘BRIDGE’ connecting 2 piconets which is also a slave in individual piconets.
- 11. SCATTERNET TOPOLOGY (contd.)SCATTERNET TOPOLOGY (contd.) Advantages of Scatternet: • Higher throughput • Multi-hop connections between devices in different piconets.
- 12. SMART SENSOR NETWORKSSMART SENSOR NETWORKS • Challenge: It is to ensure interoperability among various Bluetooth manufactures’ devices and to provide numerous applications. • 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.
- 13. WIRELESS SENSOR NETWORKS (WSN)WIRELESS SENSOR NETWORKS (WSN) WSN consists of number of small devices equipped with a sensing unit, microprocessors, wireless communication interface and power source. Two main operations performed by WSN are: 1. QUERING – Queries are used when user requires only the current value of the observation. 2. TASKING – More Complex operation Used when a phenomenon has to be observed over a large period of time.
- 14. WSN (contd.)WSN (contd.) Functions of gateway:- • Communication with sensor networks: Shortage Wireless Communication ; Discovery of smart sensor nodes • Gateway Logic: Controlling Gateway interface and data flow ; Providing uniform access to sensors • Communication with users: Communication over Internet, WAN, Satellite, etc.
- 15. RESEARCH ISSUESRESEARCH ISSUES • There are mainly two research issues for bluetooth based smart sensor network:- 1. Hardware development issues, 2.Software development issues.
- 16. SENSOR NETWORKSENSOR NETWORK IMPLEMENTATIONIMPLEMENTATION • 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 • Gateway and Smart nodes are members of piconets and so, not more than 7 nodes can exist in the network.
- 17. Smart sensor node implementationSmart sensor node implementation For implementation of Sensor as Bluetooth Node, following components are important: • Bluetooth Device • Sensors • Microcontroller Figure: SMART SENSOR NODE IMPLEMENTATION
- 18. Software architecture of the gatewaySoftware architecture of the gateway
- 19. COMMUNICATION WITH SMARTCOMMUNICATION WITH SMART SENSOR NODESSENSOR NODES • 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.
- 20. CONCLUSIONCONCLUSION • Applications of sensor networks • Factors influencing sensor network design − Fault tolerence − Scalability − Data processing − Production cost − Transmission medium • Communication architecture of sensor networks