RID: Radio Interference Detection in Wireless Sensor Networks

Gang Zhou, Tian He, John A. Stankovic, Tarek AbdelzaherDepartment of Computer Sceince University of Virginia

INFOCOM 2005

Outline

Introduction Experiments on radio interference RID Simulation Conclusion

Introduction

Interference-connectivity

A

B

C

Introduction

B

A

C

Introduction

Interference-connectivity Connectivity-interference

B AC

Introduction

B

A

C

Experiments on radio interference ~Setup

Weak link from T to R 16.2 feet 80% packet delivery

ratio

Strong link from T to R 8.5 feet 100% packet delivery

ratio

Experiments on radio interference ~one direction

Radio Interference for a Weak Link Radio Interference for a Strong Link

Experiments on radio interference ~diff.

directions

Interference Pattern Measured for a Weak Link

Interference Pattern Measured for a Strong Link

RID: Radio Interference Detection Protocol

HD-ND Detection Information sharing Interference calculation

HD-ND Detection HD packet (with a high sending power)

ID information (2 bytes) Packet type (1 byte) To minimize the packet length and to save transmission energy

TR

HD packet

HD-ND Detection ND packet (with the normal sending power)

The ND packet’s length is fixed in order that the receiver is able to estimate when the ND packet’s transmission will end once it starts to be sensed.

TR

ND packet

Rules the receiver uses The power level sensed in T1 is as low as that

of the background noise

On the contrary, receiver thinks this data is useful and records the (transmitter ID ,power level) pair for later use

Extremely weak, and doesn’t record any information

Add-on rule for receiver to detect disturbance

The power level sensed during time period T1, is stable

The power level sensed during time period T2, is always as low as that of the background noise.

Add-on rule for receiver to detect disturbance

The power level sensed during time period T1, is stable

Variable Sensed Power Level During T1

Add-on rule for receiver to detect disturbance

The power level sensed during time period T2, is always as low as that of the background noise.

Variable Sensed Power Level During T2

Add-on rule for receiver to detect disturbance

Stable Sensed Power Level During T1 and T2

Information Sharing

T1

RT2

T3

HDND

T1 P1

Interference_In table

Information Sharing

T1

RT2

T3

HDND

T1 P1

Information Sharing

T1 P1

T3 P3

T1

RT2

T3

HDND

T1 P1

Information Sharing

T1 P1

T3 P3

A PAR PR

T1

RT2

T3T3 P3

Interference_In table

Interference_Out table

Interference_HTP table

Interference Calculation N2(D) = {(i1,i2)|(Pi1D>receiver_sensitivity) ^ <SNR}

i1 : sender i2 : jammer D : receiver

Di2(jammer)

i1

idleDi

Di

PP

P

2

1

OK

Interference Calculation N2(D) = {(i1,i2)|(Pi1D>receiver_sensitivity) ^ < SNR }

i1 : sender i2 : jammer D : receiver

Di2(jammer)

i1

Interference

Pi1D

Pi2D+Pidl

e

Interference Calculation The composite of multiple negligible jammers is not

necessarily negligible

All collision Scenarios in System

N : the number of sensor devices actually deployed{Di} : the set consisting of all nodes in the system

D1 D2 . . . . . . . . . . Dk

N2(D1)={_,_} N2(D2) N2(Dk)

N3(D1)={_,_,_} N3(D2) .

{_, _,_} . . . . . . . .

. . .

Nk(D1) Nk(D2) Nk(Dk)

RID-B : Lightweight Radio Interference Detection Protocol

T1 P1

T3 P3

T1

RT2

T3

RID-B : Lightweight Radio Interference Detection Protocol

RID-B does not take into consideration the interference cases when multiple transmitters get involved

There is no interference calculation phase in RID-B

Simulation GlomoSim

Loss Ratio

Simulation

#Retransmission

Simulation

#Control Packets

Transmission Time

Energy Consumption

Simulation

Conclusion

Our work is the first to detect radio interference relations among nodes in run-time systems

The traditional TDMA protocol, NAMA, can have up to 60% packet loss in heavy load, while the RID-B supported TDMA, NAMA-RID-B, can maintain 100% packet delivery