PowerPoint Presentationiot-summit.org/English/Archives/201203/Presentations/Thomas_Watt… · Title: PowerPoint Presentation Author: ISQED03 Created Date: 4/4/2012 12:01:31 PM

4/4/2012

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SensorsCon 2012 March 21, Santa Clara

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Standards-Based Reliable Wireless Sensor Networking

Thomas Watteyne, PhD Senior Networking Design Engineer Linear Technology/Dust Networks


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Pioneer of reliable, ultra-low power embedded wireless sensor networks (WSN)

Low power wireless SOC and networking technology leader

Acquired by Linear Technology, Dec 2011

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M2M 100

Dust Networks Overview

Over 10,000 networks in 120 countries Data centers, oil refineries, museums, mines, chemical plants, city streets, trains,

steel mills, pharma plants…and more

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CoAP

UDP

6LoWPAN

IEEE802.15.4e

The Internet of Things Stack

IEEE802.15.4

web-like interaction

Internet Integration

Low-power reliability

simple hardware


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IEEE802.11 (Wi-Fi)

IEEE802.15.1 (Bluetooth)

IEEE802.15.4

First Challenge: External Interference

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IEEE802.11b/g/n

IEEE802.11a/n

868 MHz

433 MHz

2.4 GHz 5 GHz

IEEE802.15.4

First Challenge: External Interference


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Second Challenge: Multipath Fading

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ch.11



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ch.11 ch.12

0% reliability 100% reliability


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ch.11

ch.13

ch.15

ch.17

ch.12

ch.14

ch.16

ch.18

ch.19

ch.21

ch.23

ch.25

ch.20

ch.22

ch.24

ch.26



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A B

Channel Hopping

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IEEE802.15 Task Group 4e

- Amendment to enhance and add functionality to the 802.15.4-2006 MAC to better support the industrial markets

Time Synchronized Channel Hopping

- Nodes are synchronized on a common sense of time

- Nodes send successive packets on different frequencies using a pseudo-random hopping pattern

IEEE802.15.4e - Time Synchronized Channel Hopping


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16 c

hannel offsets

e.g. 31 time slots (310ms)

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B C

D E

F G

H

I

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A super-frame repeats over time

- Number of slots in a superframe is tunable

- Each cell can be assigned to a pair of motes, in a given direction

IEEE802.15.4e - Slotted Structure

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16 c

hannel offsets


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B C

D E

F G

H

I

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IEEE802.15.4e - Slotted Structure

• Cells are assigned according to application requirements


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2.120ms

2ms

< 4.256ms 0.800ms 0.400ms

2.400ms

9.976ms

IEEE802.15.4e - A Slot

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16 c

hannel offsets


A

B C

D E

F G

H

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…and energy consumption

IEEE802.15.4e - Trade-Off


• Tunable trade-off between – packets/second


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16 c

hannel offsets


A

B C

D E

F G

H

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– latency …and energy consumption


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16 c

hannel offsets


A

B C

D E

F G

H

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– latency

– robustness

…and energy consumption



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2.120ms

2ms

< 4.256ms 0.800ms 0.400ms

2.400ms

9.976ms

Type of slot Transmitter Receiver

“OFF” - -

transmission w. ACK 6.856ms 7.656ms

Transmission w.o. ACK 4.256ms 5.256ms

Listening w.o. reception - 2.000ms

IEEE802.15.4e - Energy Consumption

“atomic” operations

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Dust Networks DN6000 – “Mote-on-chip”

TX @ +8dBm 9.7 mA

TX @ 0dBm 5.4 mA

RX 4.5 mA

Cortex-M3 @ 7.4MHz

2.4 mA

Doze mode 1.2 uA

ARM Cortex-M3 32-bit uC

IEEE802.15.4 radio


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Internet

Wireless

mesh


gateway

Example 1: “leaf” node

Activity:

- Data publication

- 80B data payload

- Published every 30s

- 80% stability paths to parents

Consumption:

- 11uA average

- 22 years lifetime (2200mAh AA)

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Internet

Wireless

mesh


gateway

Example 2: router node, with one child

Activity:

- Data publication

- Provisioning for routing

- Advertisement sent every 2sec

- Listening for join requests

- Forwarding data from child

Consumption:

- 31uA average

- 8 years lifetime (2200mAh AA)


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IEEE802.15.4e - Reliability

Doherty, Lindsay, Simon. “Channel-Specific Wireless Sensor Network Path Data”, ICCCN 2007.

44 nodes, 26 days

Printing Facility

>99.999% end-to-end reliability

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Why Standardize?

The Internet


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Interoperation - IPSO

“IP for Smart Objects”

Alliance of companies

Promote the use of IP in Smart Objects

Not a standardization body

White Papers, interop events…

www.ipso-alliance.org

http://www.ipso-alliance.org/



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Interoperation - IEEE802.15.4e


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Standards-Based Reliable Wireless Sensor Networking

Thomas Watteyne, PhD Senior Networking Design Engineer Linear Technology/Dust Networks

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Abstract

The Internet of Things revolution is quietly coming, and with it an epochal turnpoint in wireless network design. Major standardization bodies have been looking at how wireless multi-hop networks should operate reliably (WirelessHART, IEEE 802.15.4E, IETF RPL) and how they can integrate within the Internet (IETF 6LoWPAN, CoAP).

This talk will highlight the challenges faced by wireless multi-hop networks, before showing how communication protocols and standards can address these. Numerous use cases, examples and lessons learnt will be taken from open-source and commercial implementations.


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Speaker’s Biography

Thomas Watteyne is a Senior Networking Design Engineer at Dust Networks, a company specializing in ultra-low power and highly reliable Wireless Sensor Networking. He designs networking solutions based on a variety of M2M standards and promotes the use of highly reliable standards such as IEEE802.15.4e. In 2009 and 2010, he was a postdoctoral researcher at the University of California, Berkeley, working with Prof. Kristofer Pister. He created Berkeley’s OpenWSN project, an open-source initiative to promote the use of fully standards-based protocol stacks in M2M applications. He obtained his PhD in Computer Science (2008) and MSc in Telecommunications (2005) from INSA Lyon, France.

Documents

PowerPoint Presentationiot-summit.org/English/Archives/201203/Presentations/Thomas_Watt… · Title: PowerPoint Presentation Author: ISQED03 Created Date: 4/4/2012 12:01:31 PM