ZigBee for Wireless Sensor Networks ZigBee for Wireless Sensor - - PowerPoint PPT Presentation

Mark Foster, CSC / NASA Ames Rick Alena, NASA Ames

Intelligent Systems Division Discovery and Systems Health NASA Ames Research Center

ZigBee for Wireless Sensor Networks ZigBee for Wireless Sensor Networks in Space and Field Science in Space and Field Science

CENIC: Expanding our Horizons UCI, March 8, 2011

Agenda

• Why wireless sensors

– Selected application domains

• Project Objectives
• Solution: TI ZigBee devkit plus SBIR leverage
• Recent prototyping and testing
• Follow on efforts

Shroud design validation

Stiffened panels with overdesigned thickness versus

• ptimized design (Collier Research)
• Optimized: less weight (thinner construction)
• Instrumentation to validate optimized design

during testing and flight

• Wired instrumentation scope limits (weight and

location)

• Wireless: more sample points, alternate datapath

to provide distinct data fault assurance

Potential shroud sizes compared to Shuttle

Human and Robotic Exploration Testing

• Spacesuit design, monitoring
• Human-robot enhancement
• Robotic field exploration

Earth Science Technology – Sensor Webs

NASA Facilities - Smart Buildings

NASA Ames – Sustainability Base

• Smart energy profile
• Building systems

management

• Smart meters

Wireless Sensor Network Project Objectives

• Develop “Intelligent” Wireless Sensor Network

(WSN) architecture, software and applications to demonstrate fundamental concept of operations

• Consider constraints: power, space, weight, cost,

time

• Evaluate WSN technology function and

performance

• Reliability
• Throughput
• Maturity (technology readiness level)
• Evaluate WSN suitability for spaceflight

certification

• Operational environment
• Temperature, radiation, pressure, vibration, etc.
• RF interference and compatibility
• Effect on spacecraft systems
• Spacecraft systems effect on WSN
• Multipath distortion immunity

Crew vehicle artist concept Credit: NASA/Lockheed Martin

Intelligent Wireless Sensor Networks (WSN) Definition

• Conform to IEEE 1451 Smart Transducer

Interface Standards

• Form ad-hoc wireless networks with high-

reliability

• Provide fault tolerance through mesh routing
• Self-manage routing and fault tolerance
• Provide Transducer meta-information
• Provide unambiguous sensor data with

temporal determinism

• Provide standard interface to TCP/IP networks
• Support open software architecture and

applications

Intelligent WSN Standards / Open development

• IEEE 802.15.4 provides protocol for ad-hoc Personal Area

Network (PAN) formation and management at MAC Layer

• IEEE 1451 Standard provides architecture for WSN
• 1451.0 Network Capable Application Processor (NCAP)
• 1451.4 Transducer Electronic Datasheets (TEDS)
• 1451.5 Wireless Transport Protocols (ZigBee)
• ZigBee provides framework for network and application

support

• C language for ZigBee and NCAP firmware and bridge

software

• Texas Instruments CC2530 System on Chip (SoC)

hardware

• ARM Co-processor for NCAP
• Simple Network Monitoring Protocol (SNMP) for external

access

ZigBee Testbed Components

• Coordinator -

establishes PAN

• Routers - forward

data

• Sensor Nodes -
• riginate sensor

data stream

• Gateway - connects

PAN to IP network (embedded linux)

ZigBee Protocol Stack

• Keep approach simple:

APS layer and below

• Adapt devkit sample

code

• modify parameters and

specific functions

• Leverage key functions

within supplied object code (Z-stack)

• Significant learning

curve, but can implement complex systems with modest coding effort.

Wireless Sensor Network Testbed Demonstration

Network Capable Application Processor (NCAP) is gateway to IP networks WSN Applications on IP networks Force (0-10 lb) 3 axis accel (0-3g) 4 thermistors (0-40C) 4 thermistors (0-40C) Humidity (10-90% RHD) Pressure (0-15 PSI) Temperature (0 - 100 ˚C) Structural Monitoring Prototype Strain (10 - 1000 µe) 2 - 4 channels FLO-1 ENV-1 SDP-1 ACL-1 ARCBee A1 ARCBee A2 ARCBee A3 Router Module Zigbee Coordinator NCAP ARCBee A4

Strain Sensor Signal Conditioner Sensor End Device Strain Gauge

Bascic TEDS Table

void InitStructThermocoupleData(struct ThermocoupleData * thermocouple) { strcpy(thermocouple->Portal_Number,"192.168.2.12"); thermocouple->Sensor_Number =1; thermocouple->AD_Channel =0; thermocouple->Maximum_Physical_Value_Volts = 3.5; thermocouple->Minimum_Physical_Value_Volts = 0; thermocouple->Maximum_Electrical_Value_Volts = 3.3; thermocouple->Minimum_Electrical_Value_Volts = 0.3; thermocouple->Thermocouple_Type ='B'; strcpy(thermocouple->Cold_Junction_Source,"CJC required"); thermocouple->Sensor_Impedance_Ohms = 100; thermocouple->Transducer_Response_Time_Sec = 1.035; strcpy(thermocouple->Calibration_Date,"2007-09-13"); strcpy(thermocouple->Calibration_Initials,"TED"); thermocouple->Calibration_Period_days = 7; thermocouple->Measurement_Location_ID = 89; }

Bit Length Allowable Range Manufacturer ID 14 17 - 16381 Model Number 15 0-32767 Version Letter 5 A-Z (data type Chr5) Version Number 6 0-63 Serial Number 24 0-16777215

void InitStructBasicData(struct BasicData *Basic) { strcpy(Basic->Portal_Number, "192.168.2.12"); Basic->Sensor_Number =1; Basic->AD_Channel =0; Basic->TEDS_ID =25; Basic->Manufacturer_ID = 55; Basic->Model_Number = 0; Basic->Version_Letter = 'A'; Basic->Version_Number = 1; Basic->Serial_Number = 123456; strcpy(Basic->User_ASCII_Data,"data"); }

TEDS generation code snippet

Transducer Electronic Data Sheet Definition for WSN

Wireless Sensor Network Development Task

Integrate new sensors for specific structural and environmental monitoring

– Multi-channel temperature, atmospheric environmental sensors, load cell and accelerometer – New strain gauge sensors, acoustic emission sensors and other sensors relevant to structural health monitoring – Circuits for sensor to SoC connection compatible with battery power 3.0 VDC. – Modify ZigBee firmware and produce new IEEE 1451 Transducer Data Sheets (TEDS) representing new sensor classes and specific prototype sensors – Test new sensors and determine accuracy of measurement

Data Logs SNMP Queries

Computer Module

ARCBee Firmware Sensor Info Display Application

SNMP Queries ARCBee Sensor Module ARCBee Sensor Module

WSN Testbed Hardware/Software Integration

MOBEE-NET CC2430 Firmware

ARCBee Firmware 802.15.4 Sensor data streams plus TEDS meta-information and WSN status transferred using ZigBee Protocol SNMP Queries access sensor data streams plus TEDS meta-information and WSN status information Data Logging and Error Detection Sensor Data Display TEDS info Display WSN Status Display Gateway between ZigBee and TCP/IP networks using SNMP for defining sensor objects Ethernet

Mobitrum NCAP Module Serial

PXA-270 SNMPAgent Mn_Driver

Data Error Checking

TinyOS

WSN Prototype Demonstration GUI Mockup

STR-1 STR-2 STR-3 STR-4

Strain Sensor Chart

active

FLO-1 RSSI FLO-1 Battery

TEDS

TEDS:
ENV‐1:ENV‐T—Resistance
temperature detectors
(RTDs) Function Select Property/Cmd Description Acce ss Bits Data
type
(and
range) Units ID — TEMPLATE Template
ID — 8 Integer
(value
=
37) — Measurement — %MinPhysVal Minimum temperature CAL 11 ConRes
(–200
to
1,846, step
1) ºC — %MaxPhysVal Maximum temperature CAL 11 ConRes
(–200
to
1,846, step
1) ºC

Reliability and RF Compatibility Test Methods

• failover behavior
• PAN association time
• PAN re-association time
• Single hop and double-hop through router
• 1, 5, 10 node clusters
• 2 sec, 1 sec, 0.5 sec data rates
• loss rates under nominal conditions and monitor

RF spectrum in ISM band

• packet loss rate vs external interference
• throughput vs external interference
• 802.11 b
• 802.11 g
• 802.11 n
• Bluetooth
• multipath environment
• reflections from conductive surfaces can prevent

data transfer by creating standing wave pattern

• metallic enclosures of varying size
• packet and throughput loss rates

WSN Reliability and RF Interference Test Protocols

• ZigBee and 802.15.4 packet analyzer
• association time, orphan detection time and re-

association time

• Fail sensor node
• Fail router node
• WLAN sources to create high duty-cycle

interference

• WiSpy for ISM RF Spectrum
• packet loss with SmartRF Studio
• Directly runs CC2530 chip
• throughput with Transmit App
• Send data as quickly as possible

Sensor Failover: Single and Dual Routers

• Failover from router to

coordinator

• Failover from router to

alternate router

One-Hop PAN Association and Orphan Transition Times

• Scales well
• Reasonably

fast and consistent

• Dependent

upon data rate

• Reasonably

fast and consistent

Two-Hop PAN Association and Reconstruction Times

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• Scales well, but more traffic during PAN reconstruction

as number of nodes increases

• Reasonably fast and consistent

RF Interference Test Configuration

Zigbee Collector Zigbee Collector

iperf

WiSPY RF Spectrum Measurement

WiFi Access Point (WAP)

1 ft 1 ft 1 ft 1 ft

WLAN Client Adapter

802.15.4 802.11g, 802.11n

Smart RF Studio Computer Smart RF Studio Computer

• WLAN interference source - 802.11bgn Access Point and Client

running iperf

• Two node ZigBee test set using Smart RF Studio
• WiSpy RF Spectrum capture

WLAN Client Adapter

iperf

2.4 GHz ISM Spectrum Diagram and Baseline

• WiSpy Spectrum Monitor

trace for RF baseline

• 802.11b/g (ARC-WLAN)

WLAN on Channel 4

• Control experimental

variables for each test run

WLAN G and N Mode Interference Spectrum

• 802.11g on Chan 1
• ZigBee on Chan 11
• 802.11n on Chan 4

Simple RF Multipath Test Configuration

• Run within metallic drawers (12” X

20” X 6”) and (12” X 20” X 12”)

• 1 and -19 dBm ZigBee power output

Packet Loss Rate with Multipath and WLAN Interference

• Case 1: Baseline - no packet loss
• Case 2 and 3: Multipath yields ZERO Loss rate
• Case 4: WLAN-G yields significant packet loss
• Case 5: WLAN-N yields some packet loss
• RSSI is Received Signal Strength Indication

– Keep near the same level for comparison

Throughput with WLAN-G and WLAN-N Interference

• Zigbee Throughput - 104 Kbps to

15 Kbps with interference

• WLAN Throughput - 18.8 Mbps to

15 Mbps with interference

• Zigbee Throughput - 106 Kbps

to 45 Kbps with interference

• WLAN Throughput - 30.5 Mbps

to 21 Mbps with interference

Throughput w/ WLAN-G Interference

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Throughput w/ WLAN-N Interference

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Future WSN Development Activities

• Define single fault-tolerant Developmental and Flight Instrumentation

(DFI) architecture as baseline

• Examine scaling limitations/tradeoffs
• Extend types of sensors and TEDS supported
• Examine software/application interface alternatives

– Perform tradeoffs of SNMP, DDS, JMS and SQL – Define WNS Data Interface Protocol

• Higher-performance interface mode for instruments and increase

measurement sampling rates

• Assess acceptable environmental operating conditions
• Better characterize reliability, fault tolerance and compatibility

WSN Two-Tier Fault-Tolerant Mesh Network Architecture

Sensor End Device Coordinator B Gateway 2 Router Module Router Module Sensor End Device Sensor End Device Sensor End Device Sensor End Device Sensor End Device Sensor End Device Sensor End Device Coordinator A Gateway 1 TCP/IP Network Coord Fault Router Fault

• Redundant sensors in each module cover sensor failures
• Redundant Sensor Modules cover Module failures
• Redundant Routers cover router failures
• Redundant Coordinators/Gateways cover PAN formation

faults and Gateway faults

Module Fault Sensor Fault

X

TBD

WSN Development Team

• NASA Ames Code TI and TN development team

– Jeff Becker, Mark Foster, Thom Stone, Ray Gilstrap – John Ossenfort, Pete Wilson, Rick Alena

• Education Associates Program - Interns

– Jarren Baldwin (now at Stanford) – Adrienne Haynes (while at Norfolk State U.)

• NASA Stennis Space Center

– Fernando Figueroa

• Mobitrum Corp

– Ray Wang and Suman Gumandevelli – NASA SBIR Phase I and II

Questions?

mark.foster@nasa.gov go, Glory!

Aerosol Polarimetry Sensor for Earth climate study TaurusXL @ Vandenberg 