Prof. K.S.J. Pister UC Berkeley, March Wireless Sensor Networks Real and Imagined. Kris Pister EECS UCB

Transcription

1 Wireless Sensor Networks Real and Imagined Kris Pister EECS UCB

2 JW9 Prof. K.S.J. Pister Wireless Sensor Networking Decision Systems Monitoring Systems Control Systems Enterprise Applications Significant reduction in the cost of installing sensor networks Enables new class of services Analog Sensors and Actuators Digital Sensors and Actuators Serial Devices Increases sensor deployment Physical World

3 Outline History in BSAC Technology Markets & Standards Future

4 IAB 1997 Autonomous Microsensor Networks with Optical Communication Links PI: Kris Pister Source: Hughes (MICRO) Funding: $25k, $10k matching, 0% ovhd, Duration: 1 year Comments: Collaboration w/ Prof. Joe Kahn under separate MICRO

5 IAB Spring 1998 Smart Dust Kris Pister DARPA $2.4M/ 3 years, under review

6 IAB Spring 2000 COTS Dust GOAL: Get our feet wet RESULT: Cheap, easy, off-the-shelf RF systems Fantastic interest in cheap, easy, RF: Industry Berkeley Wireless Research Center Center for the Built Environment (IUCRC) PC Enabled Toys (Intel) Fantastic RF problems Optical proof of concept

7 IAB Spring 2000 Low Power Radio Projects LWIM (Bill Kaiser, UCLA) MHz, 1mW goal SHARC (Tom Lee, Stanford) 1 GHz, 1mW, 1mm 2 goal picoradio (Rabaey/ Brodersen, BWRC, UCB) 100uW, 0.1nJ/bit goal

8 IAB Spring 2000 RF Sensor Future RF tags + Sensors Ultra Wide Band 10ps? digital pulse trains LLNL 60 GHz Major path loss problems But oh, the bandwidth! MEMS RF components Mechanical filters already dominate RF Never ever bet against Al and Roger

9 Brett Warneke Brian Leibowitz Mike Scott Richard Lu IAB Spring 2001 Ultra-Low Power Circuits for Distributed Sensor Networks (Smart Dust) K.S.J. Pister KSJP10 Corner Cube Reflector Optical In Capacitive XL (J. Perng) Receiver Solar Cells (C. Bellew) ADC 63mm 3 mote ASIC Mn-Ti-Li 1.5V Cell Real-Time Clock µcontroller CCR (L. Zhou) SRAM May 2001 Demonstration System Project: Low-energy circuits for cubic millimeter sensor nodes Results: 63mm 3 autonomous communication mote system functional DAC taped out CMOS micromachining process begun Future Work: (March 20) 1pJ/instruction laser reprogrammable μcontroller 1nJ/sample ADC 50pJ/bit optical receiver

10 IAB Spring 2001 Lance Doherty, Jason Hill, Michael Scott, Robert Szewczyk, Alec Woo Off-the-shelf Macromote for Smart Dust and TinyOS Prof. Pister KSJP12 Summary: Use COTS to develop and deploy sensor networks Research applications, security, and management of networks Needle piercing pig skin Recent results: TinyOS released (30+ students at first short course) Motes available from Crossbow (~$150) Future work: Air-drop deployment of sensor network Large-scale networks on campus

11 COTS-Dust, Tiny OS,& Sensorwebs Hardware, Software, and Algorithms James McLurkin, Seth Hollar, Mike Scott Jason Hill, Robert Szewczyk, Alec Woo Julius Kusuma, Lance Doherty (Culler, Pister, Ramchandran, Sastry) b Ax t t t t t v p p p p = = / δ IAB Fall 2001

12 IAB Fall 2001 Magnetometer data Raw signal (green) Event detection Bandpass filtered signal Threshold

13 IAB Fall packaged motes loaded on plane Last 2 of six being dropped

14 IAB Fall 2001 Synergy of DARPA Programs Smart Dust (MTO) COTS-Dust Autonomous UAV Endeavour (ITO) TinyOS Sensorwebs (ITO) Sensor network algorithms Fun in the desert

15 IAB Spring μm 650μm Oscillator Divider Transmitter Receiver (in fab) Inductor Chip

16 UCB Smart Dust - Integration Solar Cell Array CCR CMOS IC XL SENSORS ADC FSM PHOTO RECEIVER 16 mm 3 total circumscribed volume ~4.8 mm 3 total displaced volume 175 bps 8-bits 375 kbps TRANSMITTER OPTICAL IN OPTICAL OUT 1V 1-2V 1V 1V 3-8V 2V SOLAR POWER

17 UCB RF Mote on a Chip CMOS ASIC 8 bit microcontroller Custom interface circuits 4 External components antenna Temp up SRAM ~$1 Amp ADC Radio inductor ~4 mm^2 ASIC crystal battery

18 2 chips fabbed in 0.25um CMOS Mote on a chip worked, missing radio RX (Jason Hill) 900 MHz transceiver worked Final UCB Hardware Results Records set for low power CMOS ADC (Mike Scott) 8 bits, 100kS/s 2uA@1V Microprocessor (Brett Warneke) 8 bits, 1MIP 10uA@1V 900 MHz radio (Al Molnar) 20kbps, bits in, bits out 3V

19 Power Consumption Sensing Sensor Excitation Sensor Interface Amplifiers, filters, ADC Data processing Communication PHY/MAC/NET Algorithms/computation Encryption/security Radio TX Radio RX Distributed Signal Processing Time keeping Leakage

20 Example Dust Networks Results Mighty9 motes TI MSP430f149 Chipcon cc1000 I TX = 25mA I RX = 17mA 50 motes, two dimensional deployment, 5 hops deep Monitoring: all motes report 6 readings every 60 seconds Measured current min/mean/max: 40/80/180 ua Event reporting: < 0.1 event/mote/minute Average expected current: 60uA End-to-End Reliability Spec.: 99.9% Measured: routinely 4+ 9s in noisy environments

21 Radio Performance X cc2400 X cc2420 I RX (ma) X cc1000 cc1000 X X cc1000 X Xemics 5 X Otis (0.2mA) Molnar (0.4mA) X 100k 200k 300k Bit rate (bps)

22 Power consumption versus data rate 100M 1yr cr2032 1yr AA 2 weeks AA a,b,g Application Data Rate (bps) 1 M 10k Improved Hardware Software/algorithms Cordless phones 10μ 100μ 1m 10m 100m 1 Average Power consumption (W) 10

23 Dust Networks Incorporated July 2002 Pister on leave Jan 2003 Dec 2004 Series A Feb 2004 Series B Jan 2005 SmartMesh shipped Aug 2004

24 Configure, don t compile SmartMesh TM Console XML IP Network SmartMesh Manager Mote ~100 ft Reliability: 99.9%+ Power consumption: < 100uA average

25 Energy Monitoring Pilot SmartMesh TM Solution: Energy is the #1 cost of supermarkets after shelf stock Service: monitor, analyze and reduce power consumption Entire SmartMesh TM network installed in 3 hours (vs. 3-4 days)

26 Micro Network Interface Card μnic No network software development Variety of configurable data processing modules Integrators develop applications, not mesh networking protocols For compute-intensive applications, use an external processor/os of your choice. Analog I/O Network Services Configurable Data processing Digital I/O Serial Port

27 SAIC & Dust Networks Passive IR Passive IR and Camera 1.5 in MEMS and GPS 2.5 in 2.5 in

28 Sensor Nodes Mighty Mote Antenna Interface Microprocessor (Now called Mighty Mote) Sensor Node Packaging Antenna Option Radio Sensor and Power Interface Lithium Battery Passive IR Geophone Single Main PCB includes the sensor board with its own CPU and memory GPS Camera MEMS Microphone, Accelerometer, Magnetometer

29 Agilent ADMC 2650 Camera Grayscale difference images can be reduced to a few hundred bytes and offer potential as a detector Base Image New Image Difference images at variable quality

30 Markets & Standards

31 The Wireless World b/s (Sensor & Control Data) Sensors Decreasing Bandwidth Kb/s (Voice) Mb/s (Video) Wi-Fi Cellphones Size of market Hours Days Years Increasing Battery Life

32 Sensor Networks Take Off! Units (Millions) $8.1B market for Wireless Sensor Networks in Wi-Fi nodes Handsets Wireless Sensor Nodes Source: InStat/MDR 11/2003 (Wireless); Wireless Data Research Group 2003; InStat/MDR 7/2004 (Handsets)

33 WDRG, 2003

34 Sensor Networking Evolution Wired Networks Point-to-Point Wireless Wireless Mesh Very high reliability Low reliability Very high reliability $$$$ Installation $$ Installation $ Installation Inflexible Network Flexible Network Very Flexible Network Limited Reach Long Reach

35 Low Data Rate WPAN Applications (Zigbee) security HVAC AMR lighting control access control BUILDING AUTOMATION CONSUMER ELECTRONICS TV VCR DVD/CD remote asset mgt process control environmental energy mgt INDUSTRIAL CONTROL patient monitoring fitness monitoring PERSONAL HEALTH CARE RESIDENTIAL/ LIGHT COMMERCIAL CONTROL PC & PERIPHERALS mouse keyboard joystick security HVAC lighting control access control lawn & garden irrigation

36 Consumer vs Enterprise Class Consumer Class - Cost more important than reliability - Convenience driven - Deployed in small area - Device driven CONSUMER ELECTRONICS PERSONAL HEALTH CARE PC & PERIPHERALS RESIDENTIAL/ LIGHT COMMERCIAL CONTROL Enterprise Class - Reliability more DUST NETWORKS important than cost - Installation & mtce cost driven - Deployed in larger area - System driven BUILDING AUTOMATION INDUSTRIAL CONTROL DEFENSE

37 , Zigbee Zigbee is an industry consortium created to apply to commercial applications Toolkit functionality of PHY and low-level MAC in 15.4 Device/application profiles defined in Zigbee

38 Network Types Star Star-Mesh Full Mesh Powered mesh infrastructure Star-connected sensors No infrastructure Mesh-connected sensors

39 Cluster-tree Topology Clustered stars - for example, cluster nodes exist between rooms of a hotel and each room has a star network for control. Full function device Communications flow Reduced function device

40 Techno-Rant Reduced function devices are a non-starter for most applications Tree-based routing is fatal Cluster-tree combines both Mesh!= multi-hop Mesh = path diversity Wireless means no wires

41 IEEE PHY Overview Operating Frequency Bands 868MHz / 915MHz PHY Channel 0 Channels MHz MHz 902 MHz 928 MHz 2.4 GHz PHY Channels MHz 2.4 GHz GHz Gutierrez

42 IEEE PHY Overview Packet Structure PHY Packet Fields Preamble (32 bits) synchronization Start of Packet Delimiter (8 bits) PHY Header (8 bits) PSDU length PSDU (0 to 1016 bits) Data field Preamble Start of Packet Delimiter PHY Header PHY Service Data Unit (PSDU) 6 Octets Octets Gutierrez

43 IEEE MAC Overview Optional Superframe Structure GTS 2 GTS 1 Contention Access Period Contention Free Period 15ms * 2 n where 0 n 14 Network beacon Beacon extension period Transmitted by network coordinator. Contains network information, frame structure and notification of pending node messages. Space reserved for beacon growth due to pending node messages Contention period Access by any node using CSMA-CA Guaranteed Time Slot Reserved for nodes requiring guaranteed bandwidth [n = 0]. Gutierrez

44 Interoperability Consumer Enterprise/OEM Value of standards: Speed adoption Low cost components Vendor to vendor interoperability? System to system interoperability?

45 So what should I use? Networking Research Crossbow and/or Moteiv + TinyOS New Networking product Buy chips and stacks, write software Zigbee? Home automation Chipcon/Figure 8 Ember University? Application Buy a network, develop a product Dust Networks, Millennial Net

46 Future: Filters and Timebase will be Mechanical!

47 High-Performance Resonator Designs: the Radial Bulk Annular Resonator Bircumshaw, Pisano UC Berkeley 2003 Drive Electrode RBAR Sense Electrode Theory: g=30nm r i,r o = 197, 200um g r i r o ω=1ghz Req = 50Ω Substrate

48 Mechanically Coupled Differential Checkerboard Filter Sunil Bhave UC Berkeley 2004 Input ports Transmission (db) Frequency (MHz) Output ports f 0 = 173 MHz BW = 110 khz Ripple < 2dB Rejection = 12dB AIR Operation Footprint: 140 x 140 um

49 Electrostatic actuation with solid dielectric Howe, Bhave UC Berkeley 2004/2005

50 Integration System in Package (SIP) Post-CMOS MEMS

51 Integrated Poly-SiGe MEMS/CMOS Resonator next to Amplifier conventional layout Resonator Stacked on Amplifier smaller area lower cost reduced interconnect parasitics improved performance Andrea E. Franke, et al, IEEE/ASME JMEMS, 12, (2003). Source: R. Howe

52 Nano Dust? Nanotube sensors Nanotube computation Nanotube hydrogen storage Nanomechanical filters for low-power RF

53 Conclusion Sensor networks are everywhere today Installation is dominated by wiring costs Wireless sensor networks are now Reliable Easy to integrate & install Low cost Projected to be a multi-billion $ industry MEMS (&Nano?) will reduce cost and improve capabilities moving forward

54 Important Players Universities TinyOS (UC Berkeley, UCLA, UW, Vanderbilt, ) Startup Companies Crossbow Dust Networks Ember Figure 8 Millennial Net Major Corporate Research Groups Intel Microsoft IT: Agilent, Cisco, HP, IBM, FranceTelecom, Nortel Automation: GE, Honeywell, Johnson Controls, Siemens Zigbee Alliance