Interconnecting CITRIS and the Physical World

David Culler Computer Science Division U.C. Berkeley

www.cs.berkeley.edu/~culler Intel Research Berkeley

Breakthough Technology and Applns

Disaster Management Habitat Monitoring Condition-based maintenance Communication Actuation Sensing Processing Storage Power

I SD Q SD mixer

6/11/2002

LNA

Citris FCM EmNets 2

Bridging the Technology-Application Gap

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Power-aware, communication-centric node architecture Tiny Operating System for Range of Highly Constrained Application-specific environments Network Architecture for vast, self-organized collections Programming Environments for aggregate applications in a noisy world Distributed Middleware Services (time, trigger, routing, allocation) Techniques for Fine-grain distributed control Demonstration Applications Citris FCM EmNets 6/11/2002 3

Critical issues

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Highly constrained devices

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power, storage, bandwidth, energy, visibility primitive I/O hierarchy

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Observation and action inherently distributed

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many small nodes coordinate and cooperate on overall task

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The structure of the SYSTEM changes Devices ARE the infrastructure

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ad hoc, self-organized network of sensors

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Highly dynamic

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passive vigilance most of the time concurrency-intensive bursts

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highly correlated behavior variation in connectivity over time

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6/11/2002 failure is common Citris FCM EmNets 4

The de facto platform for EmNets

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Developed a series of wireless sensor devices TinyOS concurrency framework Messaging Model Networking stacks (RF and Serial) Multihop routing Key components

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sensing, logging, data filters, broadcast Simulation tools Database Support 6/11/2002 Citris FCM EmNets 5

Application = Graph of Components

Route map router sensor appln Active Messages Radio Packet Serial Packet Temp photo Radio byte UART ADC SW HW RFM 6/11/2002 clocks Citris FCM EmNets Example: ad hoc, multi-hop routing of photo sensor readings 3450 B code 226 B data Graph of cooperating state machines on shared stack 6

Many Research Groups using it

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UCB

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NEST SensorWeb Blackout Glaser structures CBE BFD BRWC UCLA USC, ISI Rutgers winlab Intel Bosch Crossbow

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U Wash Rutgers UIUC NCSA U Virginia, Notre Dame Ohio State, Wash. Univ.

UCSD Dartmouth MIT UT Austin, ASU, Iowa Accenture Honeywell and many more (~100) Citris FCM EmNets 6/11/2002 7

DARPA NEST Open Experimental Platform

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1,000 Micas Delivered to NEST Feb 02

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500 to UCB (Nest, Millennium), 250 to Intel Crossbow continues to manufacture

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new radio new microcontroller

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14 Demos in July 6/11/2002 Citris FCM EmNets 8

The MICA architecture

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Atmel ATMEGA103

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4 Mhz 8-bit CPU 128KB Instruction Memory 4KB RAM

51-Pin I/O Expansion Connector Digital I/O 8 Analog I/O 8 Programming Lines •

4 Mbit flash ( AT45DB041B)

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SPI interface 1-4 uj/bit r/w

DS2401 Unique ID Transmission Power Control Atmega103 Microcontroller Hardware Accelerators Coprocessor •

RFM TR1000 radio

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50 kb/s – ASK Focused hardware acceleration

TR 1000 Radio Transceiver • •

Network programming Rich Expansion connector

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i2c, SPI, GIO, 1-wire

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Analog compare + interrupts

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TinyOS tool chain

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microsecond RF synchronization primitive 10 mW active, 40 uW passive 6/11/2002 Citris FCM EmNets

4Mbit External Flash Power Regulation MAX1678 (3V)

2xAA form factor 9

Rich Sensor board

Y Axis X Axis TEMP MAGNETOMETER PHOTO Mica PINS SOUNDER Mic MICROPHONE Gain Adjustment Tone ACCELEROMETER I 2 C Bus Microphone

Environment Ranging Detection Movement

Sounder Magnetometer

6/11/2002

1.25 in Temperature Sensor Light Sensor 2.25 in

• • • • •

Discrete event simulation for large sensor networks

Re-implemensts hardware abstractions

– Individual rf modulation events, sensor events, clock events – existing applications work

Exploits TinyOS event driven structure

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host emulation down to HW abstraction

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redefine TOS macros and scheduler Event Queue Component Graphs ADC Event TEMP APP APP APP APP TEMP TEMP TEMP PHOTO PHOTO PHOTO PHOTO AM AM AM AM CRC CRC CRC CRC BYTE ADC ADC ADC ADC CLOCK BYTE BYTE BYTE RFM RFM RFM RFM Nido Implementations Allows debugging of distributed algorithms up to 1000s motes

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~100 in real time Variety of network models

4 3 2 1 0 8 7 6 5

Time to Simulate 10 Virtual Seconds Citris FCM EmNets 6/11/2002 Number of Motes (log scale) 11

Inactive Active

Controlled Test Bench

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Well-defined position Parallel access to nodes Integrated with MatLab in situ programming Localization (RF, TOF) Distributed Algorithms Distributed Control Auto Calibration !!!!

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Tokachi Port, Hokkaido - Liquifaction

Virtual data logger High Confidence in Passive state Dense Distributed Data Analysis Reclamation Rapid, cheap, installation of vertical array 6/11/2002 Citris FCM EmNets post-blast 13

Getting Ready for the great Outdoors

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in situ habitat monitoring

Packaging Sensor Suite Longevity Power Management Predictability Long-term Data Analysis Remote Management delay-tolerant network energy-based exp. design

Acadia National Park Mt. Desert Island, ME Great Duck Island Nature Conservancy

6/11/2002 Alan Mainwaring @ Intel Research Citris FCM EmNets 15

6/11/2002 Citris FCM EmNets with UCLA CENS 16

Energy Monitoring/Mgmt ‘Kits’

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Cory Hall last summer Intel “Smart Lab” Cory Environment and asset tracking Etch. Smart-Alarm Interactive Streaming Data Access Ubicomp / HCI Networking Management Privacy / Security 6/11/2002 Citris FCM EmNets 17

Distributed Query Processing over Low-Power Sensor Network

• Focus: Hierarchical Aggregation • TinyDB Software On Motes

Query

Simulatio n 6/11/2002 Citris FCM EmNets Hellerstein, Hong, Madden 18

Intel Demonstrating the Technology

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Intel Research Impact

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Intel Sales and Marketing (Jan 2002) Intel Developers Forum (Feb 2002) 100 nodes in audience of 2000 Network Discovery Power-aware routing In-Network aggregation Silly voting demo 6/11/2002 Network in Marconi Center Citris FCM EmNets 19

Meeting Social Network

6/11/2002 Citris FCM EmNets 20

Smart Fire Helmet Dick White

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CO sensor interfaced to MICA Intended to provide chemical sensing in helmet 6/11/2002 Citris FCM EmNets 21

Cots Bots and nanobots (Pister)

• Fleet of 50 Low-cost Robots • “toy” chassis + mote + stack • Motor-Servo board interfaces any combination of two motors, servos, and solenoids to a toy car platform • whisker board for obstacle detection • digital accelerometer (ADXL202) board for crude odometry • Rene => Mica

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Self-propagating Programs?

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TinyOS components support class of applns.

Tiny virtual machine adds layer of interpretation for specific coordination Primitives for sensing and communication Small capsules (24 bytes) Propagate themselves through network 6/11/2002 Citris FCM EmNets Network Programming Rate

100% 80% 60% 40% 20% 0% 0 20 40 60 80 100 120 140 160 180 200 220 240

Tim e (seconds) 23

NEST Challenge Appln

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level field (400-2500 m 2 ) with 5-15 tree-like obstacles Pursuers’ team

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400-1000 nodes 3-5 ground pursuers, 1-2 aerial pursuers Evaders’ team

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1-3 ground evaders Self organization of motes Localization of evaders

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Evaders’ position and velocity estimation by sensor network

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Communication of sensors’ estimates to ground pursuers Design of a pursuit strategy

Scheduler Localization

Minimize capture time and energy

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accuracy of localization & synch stability of network and dist. alg

Synchronization Tracking Communication Sensor Interface

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Wor ld

Strategy Planner Map Builder Pursuers’ communication infrastructure Control Signals to pursuer Tactical Planner & Regulation Vehicle level sensor fusion

GPS vision Nest Sensorweb

Vehicle coordination layer Single vehicle estimation and control layer Sensorial Information 6/11/2002 Citris FCM EmNets Physical Platform 25

Wealth of Research Challenges

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Large numbers of highly constrained (energy & capability), connected devices

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able to be casually deployed in infrastructure (existing or in design)

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imperfect operation and reliability

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operating in aggregate

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New family of issues across all the layers Several viable testbeds and study applications application service network system architecture technology Citris FCM EmNets 6/11/2002 26

The Nodes are the Infrastucture

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Simple Epidemic Algorithm Schema if (new mcast) then take local action retransmit modified request

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Examples: Network wakeup, command propagation

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Build spanning tree

»

record parent Naturally adapts to available connectivity Minimal state and protocol overhead => surprising complexity in this simple mechanism Citris FCM EmNets 6/11/2002 27

Network Discovery

6/11/2002 Citris FCM EmNets 28

Example “epidemic” tree formation

6/11/2002 Citris FCM EmNets 29

Understanding Connectivity

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16 transmit power settings For each transmit power setting, each node transmits 20 packets.

Receivers log successfully received packets.

Nodes transmit one after the other in a token-ring fashion No collisions.

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Define “range”: radius where 75% of enclosed nodes receive 75% of packets

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Often good nodes at a distance 6/11/2002 Citris FCM EmNets

probability of reception from center node vs xmit strength

30

A First Generation PicoNode

Building sensor (light, sound, Temp, humidity) • • • • •

Flexible platform for experimentation on networking and protocol strategies Size: 3”x4”x2” Power dissipation < 1 W (peak) Multiple radio modules: Bluetooth, Proxim, … Collection of sensor and monitor cards

Connectors for sensor boards

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BWRC’s First Sub-Milliwatt Node

2 chip-set (overall silicon area: 5mm 2 ) In fab by mid-fall 256 DATA 4kB XDATA 16kB CODE DW8051 microcontroller Serial Data and power networks Chip Supervisor FlashIF Serial LocalHW MAC PHY SIF ADC SIF ADC GPIO 100 m m

6/11/2002 Citris FCM EmNets 32

TinyOS on a chip

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TinyOS network stack in silicon

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synthesized from VHDL via BSAC National “bus”

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MICA on a chip

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open AVR core TinyOS stack 32 KB of memory 5 MM 2 Taped out May 20 Due in July Contains Pister/Warneke ADC Citris FCM EmNets 6/11/2002 33

Practical Means of Energy Scavenging

Piezoelectric bi-morphs PVDF PZT 90 m W/cm 3 Photovoltaic 10-1500 m W/cm 2 Capacitive converter using MEMS micro-vibrator 30 m W/cm 3 (on microwave oven)

6/11/2002

Energy-Conscious Networking

Simulated Energy Dissipation in Sensor Networks (BWRC) Performance-oriented

6/11/2002

Energy-Conscious

Citris FCM EmNets Source: R. Shah (UCB) 35

Areas for Help

• • •

Quality sensor subsystem design is surprisingly hard

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digital sensors, where art thou?

so many interfaces calibration Application studies are more demanding than anyone allocates

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planning manpower programming, programming, programming maintenance adapter to thing X mechanical engineering Platform needs to spin off non-research support element 6/11/2002 Citris FCM EmNets 36

Where to go for more?

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http://www.tinyos.net/tos/ Jason Hill, Robert Szewczyk, Alec Woo, Seth Hollar, David Culler, Kristofer Pister. System architecture directions for network sensors. ASPLOS 2000.

David E. Culler, Jason Hill, Philip Buonadonna, Robert Szewczyk, and Alec Woo. A Network-Centric Approach to Embedded Software for Tiny Devices. EMSOFT 2001.

6/11/2002 Citris FCM EmNets 37