1 / 40

Realisierungskonzepte für drahtlose Sensornetzwerke – Ein Überblick

Realisierungskonzepte für drahtlose Sensornetzwerke – Ein Überblick. Stefan von der Mark, Georg Böck. Overview. What are Wireless Sensor Networks? Similarities and differences to RFID Some published approaches PicoRadio/PicoBeacon (Berkeley) WiseNET (CSEM) MUSE and ORBIT (WINLAB)

deiter
Download Presentation

Realisierungskonzepte für drahtlose Sensornetzwerke – Ein Überblick

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Realisierungskonzepte für drahtlose Sensornetzwerke – Ein Überblick Stefan von der Mark, Georg Böck

  2. Overview • What are Wireless Sensor Networks? • Similarities and differences to RFID • Some published approaches • PicoRadio/PicoBeacon (Berkeley) • WiseNET (CSEM) • MUSE and ORBIT (WINLAB) • The AVM eGrain project • Concept • WakeUp • Demonstrator

  3. What are Sensor Networks? Smart Dust: University of Geneva in Switzerland

  4. Applications • Logistics, Locationing • Goods in a warehouse or shopping center • Books in a library • Environmental monitoring • Indoor: Temperature, humidity, intruders • Outdoor: Pollution, agricultural research • Structural monitoring • Bridges, skyscrapers, large halls • Ageing, stress from snow, earthquakes • Military

  5. Properties of Sensor Networks • Tiny little low cost sensor nodes • Wireless peer to peer communication • Self-sustained operation for prolonged time • Preferably completely integrated (CMOS) • Ad Hoc Networking:

  6. State of the Art • Existing sensor arrays are usually wired • Classical: Analog wire from each sensor • More modern: Digital bus systems • Existing wireless sensors usually communicate with dedicated access points • Sensor communication mostly proprietary,but IEEE standard 802.15.4/ZigBee exists • New IEEE 1451.4 „plug&play“ standard for • Sensor ID • Type of measurement (Units!) • Calibration data

  7. Sensor Networks vs. RFID

  8. Similarities • Low data rates • Only occasional communication • Receivers can be similar • But transmission is completely different

  9. Realisation approaches • Nothing coming close to the vision has been realized so far • Different approaches are being pursued: • Big and power hungry, but functional nodes (for protocol develompment, application research) • Demonstration of particular technologies(low power circuits, sensing, energy scavenging) • Attempts towards complete low power hardware(with reduced functionality) • And anything in between

  10. PicoNode I (UC Berkeley) • „PicoRadio Project“ at Berkeley Wireless Research Center, University of California at Berkeley (UCB) • Strong ARM CPU • Xilinx FPGA • Proxim RangeLANor Bluetooth HW withown protocols • 24 hr operation out of2 x 1200mAh Li-Ion • Variety of sensor boards (modular concept)

  11. PicoBeacon (UCB) • Energy scavenged from light and vibration • 180 W out of 1 cm3 from vibrations • 1.9 GHz transmission (no receiver) • 10m range • 2.4 x 3.9 cm2

  12. WiseNet (CSEM) • Swiss Center for Electronics and Microtechnology (CSEM) • 2 mW RX, 32 mW TX • 433 / 868 MHz ISM • 25 kbps • 25 W for 56 bytesevery 100 seconds • WiseMAC specializedMAC protocol • External Antenna

  13. Mote (Crossbow Inc.) • Commercial sensor nodes based on UCB design and TinyOS operating system

  14. Mote (cont.) • Variety of different nodes • MICA2 or 802.15.4/ZigBee protocols • 315/433/868/916MHz options (MICA) or 2.4 GHz (ZigBee) • 1 yr operation out ofAAA batteries

  15. MUSE (WINLAB) • Wireless Information Network Laboratory, Rutgers University, New Jersey • Commercial embedded computers and WLAN transceiver • Target is completeintegration

  16. ORBIT (WINLAB) • 400 nodes • Pure software testbed • No development of sensor hardware

  17. The AVM eGrain Project • AVM – „Autarke Verteilte Mikrosysteme“ • 3 year BMBF project with these partners: MWT - ANT - TKN AVM BMBF grant No. 16SV1658

  18. Concept • Development of completely autarkic ultra low power pico cell network • Nodes are self organizing, no master/slave principle • Highly integrated, node size ~1 cm3 • RF frequency 24 GHz • Development of low power system architecture • Development of ultra low power RF components

  19. Wakeup Strategies Nodes need to be in a sleep mode most of the time, but how and when to activate them?

  20. Block Diagram of the Wakeup Circuit

  21. Detector Principle • Zero bias Schottky Diodes • FET size increases from first to third stage

  22. „MOS Diode“ Diode-like behavior of an NMOS Transistor:

  23. Alternative Principle • MOS rectifier • CMOS compatible, no BiCMOS necessary • But: less sensitivity, more standby power

  24. Discriminators & Logic Adress correlator Shift registers serial data (0/1) parallel data PWM-signal Wakeup serial Input clock A1-A8 Detector reset data valid A1-A8 Adress preset Wake-Up Address Decoder • Main requirement: low power consumption • Block diagram:

  25. RF Input Vcc: + 3V Bias PWM signal Address preset Wakeup-Output Prototype of Address Decoder • CMOS-technology • Low complexity: ca. 470 transistors • No oscillator • Low data rate: e.g. 50 kb/s

  26. RF Frontend Overview • Frontend characteristics • Frequency: 24.125 GHz • Range: ca. 1 m • Transmit power: ca. 1 mW • Flip-Chip-Assemblyand integrated Antenna • IC-Technology: GaAs-HBT-MMICs (FBH) • TU Berlin (MWT, ANT), FBH

  27. Heterodyne Concept • Standard approach • Upconversion and downconversion mixers • Good channel selectivity • Oscillator needed for Tx and Rx

  28. Zero IF Concept • No oscillator needed in the receiver • Power consumption determined by LNA • Low complexity, low power consumption

  29. Baseband demonstrator • Concept • Real data transmission at 24 GHz • Patch antenna realised on multilayer PCB • Minimum component count

  30. Transmitter • On-Off-Keying (OOK) modulation • No power consumption in standby mode • No power consumption for „0“ bits

  31. Receiver • Zero IF • No mixer => no LO necessary (power saving!) • LF amplifier has very low current consumption (ca. 100 µA) • Total battery current < 15 mA • Dielectric Resonator as BPF

  32. Detector • Detector • Diode type HSCH-3486 (Agilent) • Single stage detector • Other topologies are less efficient (bridge, cascade) • PTX = 0 dBm, Pathloss (1m@24 GHz) = 76 dB=> PRX = –76dBm, Gain LNA = 13 dB=> Pin, Detector = –63 dBm=>Uout = 3 µV Matching

  33. LNA • Measured LNA performance • 14 mA DC @ 2 V • 13.3 dB gain @ 24.8 GHz • Bandwidth 4.2 GHz • NF 5.8 dB (simulated) Chipsize 1.1x1.3 mm

  34. Assembly • Aperture coupled patch antenna • Industry standard multilayer PCB • RF Chip Flip-Chip mounted • LF electronics in SMD • Housing soldered • => only standard assembly technologies

  35. Patch Antenna Principle • Whole module size is antenna base • Great beam collimation • Directivity 19.6 dB • Gain 8.5 dB (theo. Max. 9 dB) • Coax feed

  36. Aperture coupled feed • Greater bandwidth than for coaxial feed • Lower directivity of15.6 dB • Gain 7.8 dB • Fabrication much easierthan coax feed

  37. Photo • 1 cm3 • 2 button cellbatteries • 24 GHz • 2400 bps

  38. Future Work • CMOS LNA to further reduce power consumption of the receiver (7 mA @ 1.2 V) • Integration of detector with LNA • BiCMOS with schottky diodes • Pure CMOS with MOS rectifier • Complete integration as SoC

  39. Summary • Today the vision is still far from reality • But many efforts and progress are made in • Hardware design (digital and RF) • Integration and miniaturization • Energy scavenging and storage • Software design • Some day the vision will become reality!

  40. References T. T. Hsieh Using sensor networks for highway and traffic applications IEEE Potentials, vol. 23, no. 2, pp. 13 – 16, Apr-May 2004 Christian C.Enz, Amre El-Hoiydi, Jean-Dominique Decotignie, Vincent Peiris WiseNET: An Ultralow-Power Wireless Sensor Network Solution IEEE Computer, August 2004, p. 62-70 Shad Roundy, Brian P. Otis, Yuen-Hui Chee, Jan M. Rabaey, Paul Wright A 1.9GHz RF Transmit Beacon using Environmentally Scavenged Energy IEEE Int.Symposium on Low Power Elec. and Devices2003 Stefan von der Mark, Meik Huber, Mathias Wittwer, Wolfgang Heinrich, and Georg Boeck System Architecture for Low Power 24 GHz Front-End Frequenz -Zeitschrift für Telekommunikation, Special Issue Autarkic Distributed Microsystems in Sensor Networks, 3-4/2004, p. 70-73 M. Huber, S.v.d. Mark, N. Angwafo and G. Boeck Ultra low power Wakeup Circuits for Pico Cell Networks, A conceptional View Technical Report of the 1st European Workshop on Wireless Sensor Networks (EWSN), Jan 2004 Stefan von der Mark, Roy Kamp, Meik Huber and Georg Boeck Three Stage Wakeup Scheme for Sensor Networks IEEE/SBMO International Microwave and Optoelectronics Conference IMOC 2005; Brasilia, Brazil, July 25-28 http://tcs.unige.ch/doku.php/web/wirelesssensornetworks University of Geneva in Switzerland http://bwrc.eecs.berkeley.edu BWRC at UCB: PicoRadio, PicoNode, PicoBeacon http://www.csem.ch CSEM: WiseNet http://www.xbow.com Crossbow: Mote http://www.winlab.rutgers.edu WINLAB: Muse, Orbit http://www-mwt.ee.tu-berlin.de Technische Universität Berlin Microwave Engineering: AVM

More Related