Smart Merging Strategy for Configuring Power Saving Parameters in IEEE Mobile WMANs Shiann-Tsong Sheu, Chih-Cheng Yang, Shao-Jung Lu Department of Communication Engineering National Central University Hsu Wu-Hsiao Department of Computer Science & Information Engineering Ming Chuan University Youn-Tai Lee Networks & Multimedia Research Institute Institute for Information Industry ACM Mobility Conference 2008 (30.8% )

Outline Introduction Goal Parameter Mechanism Strategy (PMS) Simulations Conclusions

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

Power Saving Mechanism in IEEE e-2005 Power Saving Type I(NRT-VR,BE) Power Saving Type II(UGS,RT-VR,ERT-VR) Power Saving Type III ISWSFLW Introduction Normal Window Listening Window Sleeping Window XXXXX … ISW LW SF DL/UL Data exchange … DL/UL Data exchange LWSF X Y MS 2XX4X8X FSW ISW LW SF DL/UL Data exchange …

Introduction Multi-connections of MS Merging Strategy to Multiple PS Type Connections in Standard(802.16e-2005) Type I Connetion A Type II Connetion B Type II Connetion C Overall Power Saving Behavior

Related Work Some papers were proposed to how to set the proper parameters according to the traffic behavior Energy saving mechanism in the IEEE e wireless MAN IEEE Communications Letters Y. Xiao Adaptive Power Saving Strategies for IEEE e Mobile Broadband Wireless Access”, Proc. APCC 2006, Aug Jaehyuk Jang; Kwanghun Han; Sunghyun Choi

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 = = 1 = 8 = 4 Standard PMS 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 = Standard PMS = 3 = (1 x 3/3 + 2 x 3/4) = 2.5 = 3 = 5 MS

Merging power saving Type I and Type II connections Parameters Merging Strategy TypeII TypeI 1 TypeII

Standard = 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 ParametersValue Frame size Number of frames are observed Number of simulation run Time period of each simulation run 5ms s Simulation modelConnections PS Type ABCDABCD 2 Type I 6 Type I 1 Type I + 1Type II 2 Type II

Model A Simulations … … … Standard ISW=2 FSW=4 × 8 LW=1 SF=1 … PMS Conn 1 Conn 2

Model A Simulations

Model B Simulations … … … Standard ISW=2 FSW=4 × 8 LW=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=6 LW=1 SF=1 … PMS Conn 1 Conn 2 6 7

Simulations Model C 5

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.