a randomized power management protocol with dynamic listen interval for wireless ad hoc networks

A Randomized Power Management Protocol with Dynamic Listen Interval for Wireless Ad Hoc Networks

Zi-Tsan Chou

Vehicular Technology Conference, 2006(VTC 2006)

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Outline Outline Introduction Randomized Power Management Protocol Simulation Result Conclusion

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Introduction- Introduction- IEEE 802.11 Power

Management

Beacon Frame

Beacon Interval Beacon Interval

Beacon IntervalBeacon Interval

ATIM Window

ATIM Window

ATIM Window

ATIM Window

Sleep

Sleep

Sleep

Sleep

Time

Time

•Fixed size•Power saving•Beacon frame

XX

YY

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Introduction- Introduction- IEEE 802.11 Power

Management

Beacon Frame

Beacon Interval

ATIM Window

Time

Time

XX

YY

ATIMframe

ATIMACK Data

DATAACK

ATIM Window

ATIM Window

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Motivation- Possible forever loss of ATIM frames

IntroductionIntroduction

TimeXXXX

YYTime

Offset (X,Y)=2

Lx=3 beacon intervals

BeaconInterval

ATIM Window

Dynamic Listen Interval

ATIMFrame

ATIMFrame

T1

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Motivation- Waste unnecessary ATIM frames

IntroductionIntroduction

TimeXXXX

YYTime

T2ATIM Window

ATIM

ATIMACK

Data Data-ACK

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Randomized Power Management Protocol

RPM Protocol Eliminate the above-mentioned problems

Possible loss of ATIM frames Waste unnecessary ATIM frames The neighbor maintenance problem

Offer network flexibility in trading energy, latency, and accuracy

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Randomized Power Management Protocol

RPM Protocol Structures of Beacon Intervals Randomized Neighbor Maintenance Data Transfer Procedure Listen Interval Adjustment Procedure

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RPM Protocol- RPM Protocol- Structures of Beacon Intervals

ATIM Window

BeaconWindow

Time

NotificationWindow

Normal beacon interval (NBI)

Sleep

BeaconWindow

BW-only beacon interval (BBI)

Sleep

Sleep beacon interval (SBI)

Sleep

Time

Time

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RPM Protocol-Randomized Neighbor

Maintenance

XX

YY

NBI NBI

NBI NBI

Lx=7 ; β(beacon window ratio)=β/L=4/7

Ly=7 ; β(beacon window ratio)=β/L=4/7

RBI=6

RBI=2

RBI (Remain Beacon Interval)

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RPM Protocol-Randomized Neighbor

Maintenance Birthday paradox

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RPM Protocol-Data Transfer Procedure

Cache neighbor table MAC address, Listen Interval, RBI, the last update ti

me(Tlast) If X has a cached record about the Y

X can thus predict when Y will wake up according to Ly and its RBI.

When X has data frames for Y, X waits for the coming of Y's Notification Window.

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RPM Protocol-Listen Interval Adjustment

Procedure According to battery power or Qos considerati

on Lx=15, βx=0.4, βmin=0.2, £=0.07

Sx=[1.986]=2

XX

Lx=3 beacon intervalLx=3 beacon interval

Lx=4 beacon interval

RBI=2LI=3

RBI=2LI=4

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Simulation Result Assumptions:

Ps stations:20 Channel data rate:11Mbps Beacon frame length:61 bytes Beacon interval:100ms ATIM Window:25ms Beacon Window:8 Notification Window:25

Power consumption Doze state to awake state:0.575 mJ

transmit receive listen doze

1.65W 1.4W 1.15W 0.045W

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Simulation Result

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Simulation Result

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Conclusion RPM Protocol

PS station adjusts its listen interval dynamically Offer the network flexibility

Trading energy,latency, and neighbor discovery probability

Achieve reduction in power consumption at the expense of only a little additional delay.