Overview  Wireless Sensors Networks - WSN  TinyOS Hardware Applications Routing Technique – GPSR Implementation Future Work Summary and Conclusions

Overview  Wireless Sensors Networks - WSN  TinyOS Hardware Applications Routing Technique – GPSR Implementation Future Work Summary and Conclusions

WSN - Wireless Sensor Network consists of base actions and a number of wireless sensors (nodes). Characteristics of Wireless Sensor Networks Small size Low cost Energy constrained Ad-hoc Large number Small size implies small battery. Low cost & energy implies low power CPU, radio with minimum bandwidth and range. Ad-hoc deployment implies no maintenance or battery replacement

WSN’s are composed of large number of wireless nodes that self- organize into an infrastructure-less network – Ad-hoc network. WSN is not a typical Ad-hoc network:  Sensing and data processing are essential  WSNs have many more nodes and are more densely deployed  Hardware must be cheap; nodes are more prone to failures  WSNs operate under very strict energy constraints  WSN nodes are typically static  The communication scheme is many-to-one (base station) rather than peer-to-peer

Lifetime Nodes are battery-powered. Each operation brings the node closer to death. Designing the network to handle the energy constrained :  Sleep as much as possible  Use data fusion and compression.  Transmit and receive only if necessary.(receiving=transmitting) Scalability and Reliability self-configure and be robust to topology changes (death of a node) maintain connectivity ensure coverage: observe all phenomena in the region of interest. Maintenance Reprogramming is the only practical kind of maintenance. It is highly desirable to reprogram wirelessly.

Overview  Wireless Sensors Networks - WSN  TinyOS Hardware Applications Routing Technique – GPSR Implementation Future Work Summary and Conclusions

Developed by Berkeley specifically for networked sensors. TinyOS takes into account: What is TinyOS? An event-based operating system designed for wireless networked sensors. Designed to support concurrency-intensive operations required by networked sensors with minimal hardware requirements. Low CPU speed Power efficiency Small memory size TinyOS uses the nesC programming language to write new applications for the sensors motes.

Differences between TinyOS and Traditional OS Special purpose (not general purpose) Resource constraint No dedicated I/O controller One program at one time (no multi-programming) TinyOS Design Models Component-based model  Simple functions are incorporated in components with clean interfaces.  Complex functions can be implemented by composing components. Event-based model  Interact with outside by events (no command shell)  Two kinds of events for TinyOS: External events : Clock events and message events. Internal events triggered by external events.

TinyOS Structure Communication ActuatingSensing Communication Application Main (scheduler) Hardware Abstractions ( ADC, CLOCK, I2C, LEDS, PHOTO, UART, RFM )

Overview  Wireless Sensors Networks - WSN  TinyOS Hardware Applications Routing Technique – GPSR Implementation Future Work Summary and Conclusions

Processing BoardSensor Board Interface Board The Processor Board (mica2) which contains the micro controller that will provide all of the necessary control, processing, and communication signals to the sensors as well as the transmission of data over the wireless link station. The Sensor Board (MTS300), which contains the sensors and connects on top of the Processor Board via a 51 pin connector. This board contains 3 sensors :light, temperature and sound. The Interface Board (MIB510), which acts as a Base Station and is used for programming the Processor Board, or transferring data collected by the sensors to a PC via the serial port, or communication port.

Motes are used as the building blocks of wireless sensor networks.  Small  Low Cost  Monitor Sensor Data Components on the MICA2 mote:  ATmel ATmega 128L processor running at 4MHZ  Communicates using a MIB510 at its base node  10-bit A/D Converter so sensor data can be digitized  Limited Range (10 to 200 feet) due to power consumption

Overview  Wireless Sensors Networks - WSN  TinyOS Hardware Applications Routing Technique – GPSR Implementation Future Work Summary and Conclusions

Disaster relief operations  Drop sensor nodes from an aircraft over a wildfire Use sensor nodes to observe wildlife Intelligent buildings  Reduce energy wastage by proper humidity, ventilation, air conditioning control  Monitor mechanical stress after earthquakes Facility management  Intrusion detection into industrial sites Precision agriculture Medicine and health care  Post-operative or intensive care  Long-term surveillance of chronically ill patients or the elderly Provide better traffic - Intelligent roadside

Overview  Wireless Sensors Networks - WSN  TinyOS Applications Routing Technique – GPSR Implementation Future Work Summary and Conclusions Hardware

Routing in WSNs can be divided into flat-based routing, hierarchical- based routing, QoS-based routing and location-based routing depending on the network structure Flat-based routing - flooding, diffusion based. Hierarchical routing – Clustering. QoS-based routing - Energy Awareness Location-based routing - Known locations of nodes, GPSR. Motivation GPSR - Motivation Topology changes very rapidly in mobile wireless networks unlike wired networks. Protocols like DV and Path Vector routing algorithms don’t work well under frequent topology changes.

Uses position of sensors to make packet forwarding decisions. Every sender maintains state only about local topology. The algorithm divides into two main routing decisions:  Greedy routing  Perimeter Routing Greedy routing The next hop from a node is the neighbor that is geographically closest to the packet’s destination.

The Beaconing mechanism provides all nodes with neighbors’ positions. Beacon contains broadcast MAC address and position. In order To minimize costs and save energy the algorithm use Piggybacking – sends all known local topology with every packet. Why not to use only Greedy forwarding? Major drawback in case no neighbor is closer to the destination

Perimeter routing Right Hand Rule - Right Hand Rule - When arriving at a node x from node y, the next edge traversed is the next one sequentially counterclockwise about x from edge (x,y) Planarized Graphs - Planarized Graphs - A graph in which no two edges cross is known as planar. Two known Graphs - Two known Graphs - Relative Neighborhood Graph (RNG) and Gabriel Graph (GG) Gabriel GraphRelative Neighborhood Graph

When x and D are connected, traversing the face bordering x in either direction leads to a point y at which xD intersects the far side of the face When D is not connected to x, it lies inside an interior face or outside an exterior face. The packet tours unsuccessfully around the entirety of the face, without finding an edge intersecting xD at a point closer to D than Lf.

Overview  Wireless Sensors Networks - WSN  TinyOS Hardware Applications Routing Technique – GPSR Implementation Future Work Summary and Conclusions

 Assumptions: The Sensors are fixed positions and spread as a Grid. Every node knows the architecture of the network. Every node can die and come back to live any time.  Network Building: Every node initialized with no Alive neighbors. Each Sensor Sends Beacon message every [0.5T,1.5T] randomly to avoid collusions. Sensor who don’t gets Beacon or message from his Alive neighbor for more than 4.5T, deletes the node from his neighbor Metrics.

 Trigger Event: The Sensors Listen to the Surrounding using their Mics, when they sense 4kHz sound they start routing that knowledge to the BS.  While routing the data there are 2 phases for choosing next hop: Phase One – Greedy routing.  Neighbor Next hop is chosen according his closeness to the BS – the neighbor that is closest to the Base Station. Phase Two –  Building GG is not necessary due to network topology.  Forwarding the Data to the first edge available CCW from the source Edge.

Overview  Wireless Sensors Networks - WSN  TinyOS Hardware Applications Routing Technique – GPSR Implementation Future Work Summary and Conclusions

 Implementing mechanism that verifying connectivity from source to destination.  Spreading the application for supporting random positions of it’s nodes.  Dealing with the Mac Layer, learning and implementing energy efficient medium access control algorithms for WSN’s: Synchronizations Sleep Throughput Acknowledgments  Acquire dipper understanding on the hardware and its architecture.  QoS.

Overview  Wireless Sensors Networks - WSN  TinyOS Hardware Applications Routing Technique – GPSR Implementation Future Work Summary and Conclusions

 Learning WSN’s limitations and special characteristics.  Acquaintance with the TinyOS and nesC Language.  Writing Simple applications that uses: Timers & Leds Wireless communications Sensors and Buzzer.  Implementing the Routing algorithm “Gpsr” using all the new knowledge.