M ASTER : Long-Term Stable Routing and Scheduling in Low-Power - - PowerPoint PPT Presentation

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M ASTER : Long-Term Stable Routing and Scheduling in Low-Power - - PowerPoint PPT Presentation

M ASTER : Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks Oliver Harms 1,2 , Olaf Landsiedel 1,2 1 Kiel University, Germany 2 Chalmers University of Technology, Sweden International Conference on Distributed Computing in


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SLIDE 1

International Conference on Distributed Computing in Sensor Systems (DCOSS) 2020

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks

Oliver Harms1,2, Olaf Landsiedel1,2

1Kiel University, Germany 2Chalmers University of Technology, Sweden

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SLIDE 2

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 2

Industrial Internet of Things (IIoT)

  • Requirements:
  • High reliability
  • Low latency
  • Guaranteed

performance

  • Central Scheduling
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SLIDE 3

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 3

Contributions

  • MASTER: centralized router and scheduler
  • Targets IEEE 802.15.4 and TSCH MAC
  • Provides easy extendibility
  • Sliding Windows: transmission strategy
  • Enables flexible, stable, and reliable communication
  • Extensive testbed evaluation
  • Long-term stable schedule (24 hours)
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SLIDE 4

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 4

Outline

  • 1. Motivation
  • 2. Background
  • a. Time-Slotted Channel Hopping (TSCH)
  • b. Central Scheduling
  • 3. MASTER

a. Design

  • b. Transmission strategies: Sliding Windows
  • 4. Evaluation
  • 5. Conclusion
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SLIDE 5

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 5

Time-Slotted Channel Hopping (TSCH)

  • TDMA
  • FDMA (up to 16 channels)
  • Control information
  • Recurring Slotframes
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SLIDE 6

C-TSCH: A Centralized Scheduler for TSCH 6

Central Scheduling

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SLIDE 7

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 7

Outline

  • 1. Motivation
  • 2. Background
  • a. Time-Slotted Channel Hopping (TSCH)
  • b. Central Scheduling
  • 3. MASTER
  • a. Design
  • b. Transmission strategies: Sliding Windows
  • 4. Evaluation
  • 5. Conclusion
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SLIDE 8

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 8

MASTER

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MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 9

MASTER Overview

  • Central Scheduler
  • Routing Layer
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SLIDE 10

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 10

MASTER building blocks

Transmission Strategy Routing Scheduling

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SLIDE 11

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 11

Routing

  • Dijkstra’s shortest path algorithm
  • Metric: ETX, ETX2, or ETX3
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SLIDE 12

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 12

Transmission Strategies

  • No retransmissions
  • Slot-based retransmissions
  • Flow-based retransmissions
  • Sliding Windows
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SLIDE 13

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 13

Traditional approaches

  • No retransmissions
  • Slot-based retransmissions

A B C D

TX RX TX RX TX RX 1 2 3 A B C D TX RX TX RX TX RX TX RX TX RX TX RX 1 2 3 4 5 6 A B C D

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SLIDE 14

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 14

Sliding Windows

  • Flow-based retransmissions
  • Slot role: RX, TX, shared (RXTX)
  • Number transmissions
  • Fixed
  • 𝐹𝑈𝑌-based
  • 𝑜 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 𝑜 ∗ ∑ 𝐹𝑈𝑌!"#$

A B C D

TX RX TX RXTX RX TX RX RX RX TX TX TX RX 1 2 3 4 5 6 A B C D RXTX RXTX RXTX RXTX RXTX

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SLIDE 15

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 15

Sliding Windows in action

TX RX TX RX TX RX

A B C D

1 2 3 4 5 6 A B C D

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SLIDE 16

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 16

Sliding Windows in action

TX RX TX RX RX TX RX RX RX TX RX RX TX RX TX RX

A B C D

1 2 3 4 5 6 A B C D

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MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 17

Scheduling

  • R-LPF (Reverse Longest Path First)
  • Best-effort
  • Non deadline-based
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SLIDE 18

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 18

Outline

  • 1. Motivation
  • 2. Background
  • a. Time-Slotted Channel Hopping (TSCH)
  • b. Central Scheduling
  • 3. Master
  • a. Design
  • b. Transmission strategies: Sliding Windows
  • 4. Evaluation
  • 5. Conclusion
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SLIDE 19

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 19

Evaluation Setup

  • Testbed at Kiel University
  • 500 m2
  • 20 nodes
  • Platform: Zolertia Firefly
  • Evaluation configuration
  • 6 flows, 2-4 hops
  • 2 hours
  • 1 packet per second
  • 64 bytes payload + headers
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SLIDE 20
  • Baseline
  • Slot-based
  • 1 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 2 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 1 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 2 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 3 ∗ ∑ 𝐹𝑈𝑌!"#$

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 20

MASTER’s Transmission Strategies

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SLIDE 21

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 21

MASTER’s Transmission Strategies

  • Baseline
  • Slot-based
  • 1 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 2 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 1 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 2 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 3 ∗ ∑ 𝐹𝑈𝑌!"#$
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SLIDE 22

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 22

MASTER vs. Orchestra

  • 3 ∗ ∑ 𝐹𝑈𝑌!"#$

at night

  • 3 ∗ ∑ 𝐹𝑈𝑌!"#$

during daytime

  • Orchestra

at night

  • Orchestra

during daytime

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SLIDE 23

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 23

MASTER’s Long-Term Stability

  • 1 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 2 ∗ ∑ 𝐹𝑈𝑌!"#$
  • 3 ∗ ∑ 𝐹𝑈𝑌!"#$
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SLIDE 24

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 24

Conclusion

  • MASTER: centralized router and scheduler for TSCH
  • Sliding Windows: flexible and stable transmission strategy
  • Implementation available at

https://github.com/ds-kiel/master-scheduler

  • Long-term stable schedules
  • Outperforms Orchestra latency wise
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SLIDE 25

MASTER: Long-Term Stable Routing and Scheduling in Low-Power Wireless Networks – Oliver Harms 25

Thank you for your attention

https://github.com/ds-kiel/master-scheduler

  • ha@informatik.uni-kiel.de