Smart Merging Strategy for Configuring Power Saving Parameters in IEEE 802.16 Mobile

WMANs

Shiann-Tsong Sheu, Chih-Cheng Yang, Shao-Jung LuDepartment of Communication Engineering

National Central University

Hsu Wu-HsiaoDepartment of Computer Science & Information Engineering

Ming Chuan University

Youn-Tai LeeNetworks & Multimedia Research Institute

Institute for Information Industry

ACM Mobility Conference 2008 (30.8% )

Outline

Introduction Goal Parameter Mechanism Strategy (PMS) Simulations Conclusions

Introduction

IEEE 802.16e-2005 cops with Mobile environment Mobile Station(MS) : Using batteries as their power sources How to reduce power consumption to prolong the battery life

IEEE 802.16e-2005 defines the Power Saving Mechanism which allows an MS to stay in sleep mode for saving its power.

Power Saving Mechanism in IEEE 802.16e-2005 Power Saving Type I(NRT-VR,BE)

Power Saving Type II(UGS,RT-VR,ERT-VR)

Power Saving Type III

Introduction

Normal Window Listening Window Sleeping Window

X XX X X …

ISW LWSF DL/UL Data exchange

SFFSWEFSWB 2

X Y

MS

MS

MS

2XX 4X 8X FSW

FSWEFSWB 2ISW LWSF DL/UL Data exchange

…

Introduction

Multi-connections of MS Merging Strategy to Multiple PS Type Connections in Standard(802.16e-2005)

Type IConnetion A

Type IIConnetion B

Type IIConnetion C

Overall PowerSaving Behavior

Goal

Hope to provide a smart merging strategy to

moderate the parameters of each power saving types and synchronize the sleep behavior of all connections

In order to achieve better power saving efficiency and less access delay

Parameters Merging Strategy (PMS)

Merging power saving Type I connections Merging power saving Type II connections Merging power saving Type I and Type II connections

Power Saving Type I Connection1

Power Saving Type II Connection i

…

Merging power saving Type I connections

System model

Power Saving Type I Connection 1( )

Power Saving Type I Connection 2( )

…Power Saving Type I Connection 3( )

Merging power saving Type I connections Parameters Merging Strategy

Minimal initial latency

Enough frames to listen

Minimize the maximum latency

Shorten the delay of entering sleep mode

Merging power saving Type I connections Parameters Merging Strategy

= <ISW=1 , LW=1 , FSWB=4 , FSWE=1 , SF=4>

= <ISW=2 , LW=1 , FSWB=4 , FSWE=1 , SF=6>

= 1 = 1 = 8 = 4

Standard

PMS

MS

MS

Merging power saving Type II connections

System model

Type II Connection 1( )

Type II Connection 2( )

…Type II Connection 3( )

Merging power saving Type II connections Parameters Merging Strategy

Minimal initial latency

Enough frames for all connections to exchange data

Shorten the delay of entering sleep mode

ratio

Merging power saving Type II connections Parameters Merging Strategy

= <ISW=3 , LW=1 , SF=5 >

= <ISW=4 , LW=2 , SF=5 >

Standard

PMS

= 3 = (1 x 3/3 + 2 x 3/4) = 2.5 = 3

= 5

MS

MS

Merging power saving Type I and Type II connections Parameters Merging Strategy

TypeII

TypeI

}),(,min{

}2,2min{

jXFSWBISW

FSWBpreeSWSWIj

IIMerged

FSWEIMerged

IMerged

1

TypeII

Standard

= <ISW=3 , LW=1 , SF=5 >

= <ISW=5 , LW=2 , SF=3 >

= <ISW=1 , LW=1 , FSWB=4 , FSWE=1 , SF=4>

= <ISW=2 , LW=1 , FSWB=4 , FSWE=1 , SF=6>

<ISW=3 , LW=3 , SF=3 >

<ISW=3 , LW=3 ,FSWB=3,FSWE=0, SF=3 >

PMS

Merging power saving Type I and Type II connections

Flow chart of configuring parameters

Merging power saving Type I and Type II connections

Simulations

Parameters ValueFrame size

Number of frames are observed

Number of simulation run

Time period of each simulation run

5ms

1000

1000

5s

Simulation model Connections PS TypeA

B

C

D

2 Type I

6 Type I

1 Type I + 1Type II

2 Type II

Model A

Simulations

…

…

…Standard

ISW=2 FSW=4×8LW=1 SF=1

…PMS

Conn 1

Conn 2

Model A

Simulations

Model B

Simulations

…

…

…

Standard

ISW=2 FSW=4×8LW=1 SF=1

…

…PMS

…

…

Conn 1

Conn 6

Conn 5

Conn 4

Conn 3

Conn 2

Simulations

Model B

Model C

Simulations

…

…

…Standard

ISW=6 FSW=6LW=1 SF=1

…PMS

Conn 1

Conn 2

6

7

Simulations

Model C5

Simulations

Model D

Conclusions

A smart parameter merging strategy (PMS) for merging the parameters of power saving Type I and/or Type II as single parameter set in order to maximize sleeping periods and synchronize the sleep behavior of all connections.

The proposed PMS outperforms the standard method in terms of power consumption and access delay.