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Wireless Sensor Networks. Kris Pister Founder & Chief Technologist, Dust Networks (Prof. EECS, UC Berkeley). Dust sells reliable, low power mesh networks to OEMs. OEMs. End Users. Evolving information flow in WSN. DB. Business logic. Custom APP. APP. Manager. LBR. IPv6,
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Wireless Sensor Networks Kris Pister Founder & Chief Technologist, Dust Networks (Prof. EECS, UC Berkeley)
Dust sells reliable, low power mesh networks to OEMs OEMs End Users
Evolving information flow in WSN DB Business logic Custom APP APP Manager LBR IPv6, native DB fmt. Proprietary network & data fmt. Network stack Network stack Oski (SPOT-lite)? Application Mote Serial API Sensor mP Sensor Application Sensor 3
Outline • Applications • Standards • Technology
Outline • Applications • Industrial Process Automation • Commercial Building Automation • Parking management • Smart Rail • Vibration monitoring • Smart Grid • Standards • Technology
Sampling of Wireless HART Products • Battery • Vibration • Battery • 4-20 mA loop • Solar • Battery • 4-20 mA loop • Thermal • Thousands of networks, dozens of countries, six continents • buildings, breweries, refineries, mines, city streets, chemical plants, deserts, trains, steel mills, data centers, pharmaceutical plants, offshore oil rigs…
WirelessHARTTM Adapters Siemens SITRANS AW200 ABB Adapter Emerson THUM MACTek BULLET
Wheeling-Pittsburg Steel Need to monitor temp, coolant, lubrication Hot slag defeated wired solutions 5% improvement in productivity (reduced maintenance) 10
Lime Kiln at Pulp & Paper Mill • Rotating lime kiln • Need to monitor temperature • 5% throughput improvement (reduced process time) 11
Wireless Sensors Grane Platform, North Sea • 22 pressure sensors • 90% reduction in installation cost 12
Shell Oil, Norway Wireless mesh network 2 km 1 km • GE Energy’s System 1 motor condition monitoring • 200 temperature and vibration sensors • No line power due to hazardous location rules
Richmond Refinery Wireless Umbrella • Next • Fence monitoring • H2S, VOC • Location 5 km2, 90% coverage 15
Smart Building: Federspiel Controls • HVAC optimization to conserve energy • CA Tax Board savings: 459,000 kWh/yr, $55,000/yr (1 yr payback) • No wires, no interruption to data center operations 16
Smart Cities: Streetline Networks Wireless sensor node 20
Smart Rail • TSCH WSN enables remote monitoring of freight cars • Multiple sensors per car, every car is a network • Requires a strict ‘no-wires’ solution, robust enough for moving railcars
Outline • Applications • Standards • TSMP • Zigbee • 802.15.4E • IETF • Technology
Time Synchronized Mesh Protocol (TSMP & TSCH) • Basis of several Industrial Automation Standards • IEC 62591 (WirelessHART) • ISA100.11A • WIA-PA (China) • MAC is standardized in 802.15.4E (TSCH) • Multiple network vendors: Dust, Nivis, STG, … • Best performance • Highest reliability • Lowest power • Lowest latency • Largest scalability • Accurate timestamps
Zigbee • The big three • Zigbee Pro / SE1.0 • Zigbee RF4CE • Home entertainment control • Guarantees that cell phones will have 15.4 radios • Zigbee IP / SE2.0 • http, TLS, DHCP, … • Zigbee Green Power • All use powered routers • LPR getting little traction • Interoperability • AODV • Provisioning
802.15.4E • A tale of four standards • PAR: “time synchronized channel hopping” “in support of industrial automation” • TSCH • LE • FA • DSME
IETF • 6LoWPAN • IPv6 adaptation layer • RoLL/RPL • Gradient routing • CoRE/CoAP • These are the building blocks • Zigbee IP / SE2.0 • Something with 802.15.4E?
Protocol Integration Application Presentation Session Transport Network Data-Link Physical HTTP, SSH, Telnet, FTP “other” CoAP, XML, IETF UDP ,TCP WSN RDP? RoLL RPL IPv6 IEEE802.3 IEEE802.11 6LoWPAN 802.15.4, 4e IEEE 802.15.4 Tomorrow’s Internet of Things Today’s Internet
Outline • Applications • Standards • Technology • TSMP • Oski • SPOT
TSMP Foundations • Time Synchronization • Reliability • Power • Scalability • Reliability • Frequency diversity • Multi-path fading, interference • Spatial diversity • True mesh (multiple paths at each hop) • Temporal diversity • Secure link-layer ACK • Power • Turning radios off is easy
Power-optimal communication A B A wakes up and listens B transmits B receives ACK A transmits ACK Worst case A/B clock skew • Assume all motes share a network-wide synchronized sense of time, accurate to ~1ms • For an optimally efficient network, mote A will only be awake when mote B needs to talk Expected packet start time
Packet transmission and acknowledgement Radio TX startup ACK RX Packet TX Radio TX/RX turnaround Mote Current (2011): 15 mC (2008): 50 mC Charge cost (2003): 300 mC
Idle listen (no packet exchanged) Empty receive Radio RX startup Mote Current (2011): 5 mC (2008): 27 mC Charge cost (2003): 70 mC
Mesh Networking • 802.15.4 PHY, 2.4 GHz • Time Synchronized for low power & scalability • All nodes run on batteries, for 5-10 years • Channel Hopping and full mesh for reliability • 99.999% “best effort” packet delivery IP Gateway IEEE 802.15.4 Mote Sensor
Relative time error • Simulated. 8 hops, low traffic Extreme temp 8 hops, high traffic Extreme temp 2 hops, low traffic Room temperature
Absolute time synch NTP Stratum 1 server PM or LM Mote • Relative error: 0.1ms avg., 1ms max • Absolute error on PM: • 0.3ms avg. ; 99.9% <1ms; 10ms worst case • 1us w/ 1588 42
Oski Future-proof horsepower 32 bit ARM Cortex M3 512kB flash, 72kB RAM Revolutionary radio & network IPv6 router < 20μA 10 years with an AA lithium battery Microsecond timestamps Location Fast application development Multi-protocol routing 6LoWPAN Zigbee SE 1, 2; Pro HART
Mote-on-chip current vs. sample date RX Current 0dBm TX Current Jennic CEL Ember Freescale Ember TI Jennic TI MSP430 +CC2420 Freescale Dust Networks Dust Networks
Location RTLS costs often dominated by infrastructure Power and/or data cabling for readers Barrier to initial deployment 47
SmartMesh SPOT Asset Management System & Location Engine Locn: Room 327, west wall Fixed Battery Powered Mote Network Manager 27.2m 22.5m 40.1m Mobile Mote 17.8m 23.2m Sensor 48 48
SmartMesh SPOT Advantages • No site survey • Field-proven, self-forming, self-healing TSCH mesh • No wires • Battery/scavenger-powered “peel-and-stick” infrastructure • …and a true IP network • Sensors: button, temp, shock, … • Outputs: displays, alarms, …
Theory only goes so far Dr. Lance Doherty Dust Networks’ System Architect Dr. Mark Lemkin Dust Networks’ Lead RF designer 50