View
212
Download
0
Category
Preview:
Citation preview
Advanced Mechanisms for Sleep Mode Optimization of VoIP Traffic over IEEE
802.16m
IEEE Globecom 2010
Ritesh K. Kalle, Maruti Gupta, Aran Bergman, Elad Levy, Shantidev Mohanty, Muthaiah Venkatachalam and Debabrata Das
Speaker: Wun-Cheng Li
Outline• Introduction• Goal• VoIP Specific Advanced Power Save Mechanisms
▫ Sub-frame level sleep operation▫ Discrete Listening Window Extension (DLWE)▫ Different sleep cycle configuration for active and inactive periods
• Simulation• Conclusion
2
Introduction• IEEE 802.16m standard provide VoIP traffic services over
WiMAX channels.
• VoIP traffic is uniquely characterized by small packets sent regularly at periodic.
3
Introduction• Power saving is a critical issue for mobile wireless devices
▫ Mobile devices are normally battery-operated
• In IEEE 802.16m, four power saving types are defined for different connections with the specific QoS requirement
4
Introduction• Three IEEE 802.16e/m power saving classes
5
…
TS_init
2 x TS_init TL
(TS_max)
TL TS
…
TS
normal operation
sleep windows
listening windows
Type I :
Type II :
Type III :
Introduction• Three IEEE 802.16m power saving classes
▫ Type IV
6
Introduction• A typical VoIP session is a two-way conversation
characterized by silence and talk periods.
8
A B
A B
A B
A B
Talks
Silent
Introduction• A typical VoIP session is a two-way conversation
characterized by silence and talk periods.▫ Let Pij represent the probability of transition from state i to state j.
9
Goal• The proposed VoIP Specific Advanced Power Saving
Mechanisms reduces the average power consumption
10
VOIP Specific Advanced Power Save Mechanisms
• Sub-frame level sleep operation▫ The MAP information is sent during every DL sub-frame▫ MS has to remain awake for the entire duration of DL sub-frames
11
DL Subframe
UL Subframe
DL Sleep
UL Sleep
DL MAP HARQ FB
Listening Window Sleeping Window
UL VoIP
DL:UL 4:4 subframes
VOIP Specific Advanced Power Save Mechanisms
• Sub-frame level sleep operation▫ Limiting the MS to remain awake sub-frames
MAP information elements (IEs) VoIP traffic HARQ control
12
HARQ FBDL MAP
UL VoIP
Listening Window Sleeping Window
DL:UL 4:4 subframes
DL Subframe
UL Subframe
DL Sleep
UL Sleep
VOIP Specific Advanced Power Save Mechanisms
• Discrete Listening Window Extension (DLWE)
13
DL MAP HARQ FB
UL VoIP
DL:UL 4:4 subframes
DL Subframe
UL Subframe
DL Sleep
UL Sleep
NAK + DL MAP
HARQ FB
ACK + DL MAP
UL HARQ Retx
VOIP Specific Advanced Power Save Mechanisms
• Different sleep cycle configuration for active and inactive periods▫ Persistent allocation to reduce scheduling overhead which would reduce
the activity period per frame to schedule the VoIP or SID packet.
14
Simulation• MATLAB
15
Parameter SettingsIEEE 802.16m Frame Time 5 msUL: DL ratio 5:3Max. no. of HARQ retransmissions (RTT =5 ms) 4VoIP codec AMRTotal number of VoIP users 200Length of AAI_SLP-REQ/ AAI_SLP-REQ 64/80 bitsLength of SCH/SCEH 24 bitsTotal simulation time 2000 s
Simulation
16
Simulation• Sleep Cycle
18
Simulation• Signaling Overhead
19
Conclusions• This paper proposed novel mechanisms to substantially
improve power savings for VoIP traffic in IEEE 802.16m.
• These mechanisms lead to power savings of up to 70% and can improve further with sleep cycle adaptation for mutual silence periods.
20
Thank you!
21
Recommended