Localization with RSSI Method at Wireless Sensor Networks Osman Ceylan Electronics Engineering PhD Student, Istanbul Technical University, Turkiye ITU WSN TEAM

Presantation Plan Networks −Computer Networks −Wireless Sensor Networks Hardware specifications Advantages Localization Problem −Localization techniques −RSSI Method ITU WSN TEAM

Networks Computer Networks ITU WSN TEAM

Networks Wireless Sensor Networks Remote Control Local Control Event Nodes Alternative path Sensor area ITU WSN TEAM

Wireless Sensor Networks −Wireless sensor networks and computer networks are similar. Able to send/receive data Internal control unit −But there are some significant differences. Very small hardware Wireless communication ITU WSN TEAM

Hardware Specifications Hardwares are low power small devices. −Working with battery for 6-24 months −Easy installing and carring Communicaton is wireless. −Generally uses ISM bands ( Especially 433 MHz and 2.4 GHz) −Low communication range (up to 200 meters at outdoor) Microcontroller is processing unit. −Analog and Digital I/O −Internal RAM, Flash ITU WSN TEAM

Advantages of WSN’s Versus Wireless Computer Networks Wireless sensor networks can be designed and implemented much more bigger than computer networks easily and cheaply. Network organization can be setted up automatically by the hardwares. Hardwares: −Very low power consumption −Very low failure rates ITU WSN TEAM

Localization Problem How can we find an object’s exact position? −Triangulation ITU WSN TEAM

Localization Techniques GPS −Only outdoor −1-15 meters error GSM −Bad in cities −100 meters error Sensor Networs −Ultrasonic Based Systems Very High Accuricy (under 5 cm), but very low range (max 10 meters) Hard setting up Not user friendly −RSSI Based Systems 1 meter error ITU WSN TEAM

RSSI Method Received Signal Strength Indication is a measurement of the received signals power. Radio frequency signals’ power decreases with the distance: −Loss (dB) = 20log(d)+20log(f) −d=km, f=MHz We know communication frequency and transmit power.So if we can measure received signals power’s: We can find the distance d. −Received Power = Transmited power – Path Loss ITU WSN TEAM

RSSI Method ITU WSN TEAM Fixed Node x3,y3 Fixed Node x2,y2 Fixed Node x1,y1 Fixed Node x4,y4 Moving Node R1 R2 R3 R4

Advantages of RSSI Method at Localization No directional sensor like ultrasonic systems Indoor and outdoor usage Data communication and sensor usage at same hardware ITU WSN TEAM

Difficulties at RSSI Method Distance calculation is related RF signal power at receiver. −Multipath propagation −Fading effects −Bad frontend devices ITU WSN TEAM

Industrial Usage Data collection −Sensor datas collecting Temperature maps producing Tracking and location −Object tracking at production lines −Person tracking at hospitals, penitentiaries −Animal tracking at farms ITU WSN TEAM

Defence Systems Ammunition Tracking in a war or storage Soldier Tracking in a war or trainging Detecting ally or enemy Data collection −For a person dead/alive −For a object existing/operating/moving ITU WSN TEAM

Team Electronics Circuits and Antennas Design Team −1PHd, 4 BSc Embedded Design Team −2 Msc, 6 BSc Command-Control Software Design Team −1 MSc, 4 BSc ITU WSN TEAM

Thanks ITU WSN TEAM