RID: Radio Interference Detection in Wireless Sensor Networks

1
RID Radio Interference Detection in Wireless
Sensor Networks

• Gang Zhou, Tian He, John A. Stankovic, Tarek F.
  Abdelzaher
• Computer Science Department, University of
  Virginia
• March 2005

2
Outline

• Motivation, State of the Art, and Contributions
• Radio Interference Detection Protocols
• RID protocol
• RID-B protocol
• Using Radio Interference Detection in TDMA
  Designs
• Conclusions and Future Work

3
Motivation

• Use Communication Topology as the Basis of TDMA
  Designs
• One popular example
• Assume collision free by allowing one node,
  within two communication hops, to transmit
  packets at a time.
• Using Communication Topology is Misleading

How about K hops communication topology?
We Need to Detect Radio Interference!
K needs to be gt 2 !
K needs to be lt 2 !
4
State of the Art

• Communication Topology is Widely used as the
  Design Basis of TDMA Protocols
• In MANET NAMA protocol Bao and
  Garcia-Luna-aceves 2001
• In WSN TRAMA protocol Rajendran et al.
  2003
• Pervasive Existence and Complexity of Radio
  Interference are Reflected in Recent WSN
  Experiments
• Shadowing Phenomena Woo et al. 2004
• Radio irregularity Zhou et al. 2004
• Packet delivery performance Zhao and Govindan
  2003
• Reliable multihop routing Woo et al. 2003
• Connectivity assessment tool Cerpa et al. 2003

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Contributions

• To the best of our knowledge, our protocols, RID
  and RID-B, are the first to detect radio
  interference topology in runtime systems
• Apply radio interference detection in TDMA design
  (take NAMA as a case study)
• NAMA-RID-B keeps 100 packet delivery ratio
• In heavy load, NAMA can have packet loss up to
  60
• Analyze the application of radio interference
  detection in backoff algorithms.
• (See paper for detail)
• Study the relationship between communication
  range and interference range in MICA2 devices, in
  both strong link case and weak link case.
• (See paper for detail)

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RID Protocol

• RID Phases
• HD-ND Detection
• Information Sharing
• Interference Calculation

Range 1 As High Sending Power Communication
Range Range 2 As Normal Sending Power
Interference Range
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RID Protocol

• System wide solution
• Random back off

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RID Protocol

• System wide solution
• Random back off
• Add-on rule

Condition A Stable power level during
T1 Condition B Stable low power level
(background noise power) during T2
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RID Protocol

• System wide solution
• Random back off
• Add-on rule

Condition A Stable power level during
T1 Condition B Stable low power level
(background noise power) during T2
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RID Protocol

• System wide solution
• Random back off
• Add-on rule

Condition A Stable power level during
T1 Condition B Stable low power level
(background noise power) during T2
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RID Protocol

• System wide solution
• Random back off
• Add-on rule
• Multi-round Detections

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• RID Phases
• HD-ND Detection
• Information Sharing
• Interference Calculation

Interference_In Table
Interference_Out Table
Interference_HTP Table
ID1 Power1
ID2 Power2
ID3 Power3

ID10 Power10
ID11 Power11
ID12 Power12

ID21 Power21
ID22 Power22
ID23 Power23

This Phase generates two more tables
Record Who can interfere with one of my
neighbors and how much it is
Record Who can interfere with me and how much it
is
Record Who I can interfere with and how much it
is
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• RID Phases
• HD-ND Detection
• Information Sharing
• Interference Calculation

• Goal Figure out All Collision Cases by Local
  Calculation
• Basic Step
• Calculate possible interference cases at receiver
  D, when there are only two simultaneous
  transmitters

• (1) Node i1s signal can be disturbed by node
  i2s signal
• (2) Without interference, node i1s signal is
  able to be received by node D

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Interference Calculation --- Extension Step

• Extension How about k simultaneous transmitters?

• (1) Node i1 signal can be disturbed by the sum
  of node set i2, , ik
• (2) Without interference, node i1s signal is
  able to be received by node D
• (3) Any proper subset of node set i2, , ik
  can not generate enough interference

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Interference Calculation --- Properties

• Two interesting properties of

Has no Redundancy
Is complete
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RID-B Protocol

• Motivation of RID-B
• Future traffic information is needed to take full
  use of Nk(D) in RID.
• Very expensive, especially in WSN
• RID-Bs concern Detect nodes that can interrupt
  the receivers reception of the weakest packet
  from nodes within its communication neighborhood.

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RID-B Calculation

• How to achieve that?
• The same way to build Interference_In table
• Reorganize the Interference_In table
• Replace entry (transmitter ID, power level) with
  entry (transmitter ID) if the following condition
  is met
• Entry is removed, if the condition is not met

Weakest signal power level from Rs communication
neighbors (C here)
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Using RID-B in NAMA Protocol

• NAMA Protocol
• Scheduling is based on 2 hops communication
  topology.
• Each node makes local decision whether it can
  have the current time slot, based on IDs in two
  communication hops.
• Without communication, there comes a consensus.
  Only one node wins the time slot.
• NAMA-RID-B Protocol
• Scheduling is based on 2 hops of interference
  topology.
• Each node makes local decision whether it can
  have the current time slot, based on IDs in two
  interference hops.
• Without communication, there comes a consensus.
  Only one node wins the time slot.

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Simulation Configuration
Components Setting
Simulator GloMoSim
Terrain (144m X 144m) Square
Node Number 144
Node Placement Uniform
Payload Size 32 Bytes
Application Many-to-one CBR streams
Routing Protocol GF
MAC Protocol NAMA/NAMA-RID-B (ACK added, Max Retransmission is 8)
Radio Model RADIO-ACCNOISE
Radio Bandwidth 250Kb/s
Radio Range 25m (Adjust parameter values to set different interference range)
Confidence Intervals The 90 confidence intervals are shown in each figure
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Performance Evaluation
Performance with Different System Load
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Overhead
Performance with Different System Load
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Performance with Different ICR and SNR
(b) Performance with Different SNR Threshold
(a) Performance with Different ICR (ICRRI/Rc)
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Conclusions

• To the best of our knowledge, our protocols, RID
  and RID-B, are the first to detect radio
  interference topology in runtime systems
• Apply radio interference detection in TDMA
  design. It improves NAMAs packet delivery ratio
  from 40 to 100, in heavy load.
• Analyze the application of radio interference
  detection in backoff algorithms.
• Study the relationship between communication
  range and interference range in MICA2 devices, in
  both strong link case and weak link case.

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Future Work

• Predict future traffic information, and combine
  it with RID to design more bandwidth efficient
  TDMA
• Explore the use of RID-B in backoff algorithms in
  detail
• Analyze the combination of RID with topology
  control protocols
• Implement and evaluate radio interference
  detection in a large-scale sensor network system
• Explore the interaction between radio
  interference and radio irregularity

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Thanks to anonymous reviewers for their valuable
comments!
The End!