以流量為基礎之 ieee 802.16e 睡眠排程機制 a load-based power saving and scheduling...
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以流量為基礎之 IEEE 802.16e 睡眠排程機制 A Load-based Power Saving and Scheduling Scheme in IEEE 802.16e. 國立暨南國際大學 資訊工程系 楊峻權 2010.05.04. Outline. Introduction Wireless Standards, IEEE 802.16e/m Power Saving Techniques IEEE 802.16e/m Power Saving Class Related Work Load-based Power Saving - PowerPoint PPT PresentationTRANSCRIPT
以流量為基礎之以流量為基礎之 IEEE 802.16eIEEE 802.16e 睡眠排程機睡眠排程機制制
A Load-based Power Saving and A Load-based Power Saving and Scheduling Scheme in IEEE 802.16e Scheduling Scheme in IEEE 802.16e
國立暨南國際大學國立暨南國際大學資訊工程系 楊峻權資訊工程系 楊峻權
2010.05.042010.05.04
2
Outline Introduction
Wireless Standards, IEEE 802.16e/m Power Saving Techniques IEEE 802.16e/m Power Saving Class Related Work
Load-based Power Saving LBPS-Aggr, LBPS-Split, LBPS-Merge
Performance Evaluation Conclusion
3
Wireless Standards
802.15.1Bluetooth
802.15.3802.15.4Zigbee
Personal Area Network (PAN)
802.11Wi-Fi
Local Area Network (LAN)
802.16/WiMaxFixed Wireless MAN
Metropolitan Area Network (MAN)
802.16e/mNomadic
802.20Mobile
802.21Handoff
802.22WRAN
2, 2.5, 3GCellular
Wide Area Network (WAN)
4
IEEE 802.16 Standards (1)
Standard 802.16 802.16a 802.16-2004 802.16e
應用模式 固定式應用(取代寬頻設備) 移動式應用
應用方向 Last Mile & Backhaul Mobile Device
頻段 10~66 GHz 2~11 GHz 2~6 GHz
傳輸條件 LOS NLOS NLOS
傳輸速率 32~134 Mbps 75 Mbps 15 Mbps
調變技術 QPSK, 16QAM,
64QAM
QPSK, 16QAM, 64QAM
(採 256 Subcarrier OFD
M)
QPSK, 16QAM, 64QAM
(採 257 Subcarrier OFDM
)
移動性 固定性 固定性 移動性
傳輸距離 1~3 Miles 4~6 Miles (Max 30 Miles) 1~3 Miles
5
IEEE 802.16 Standards (2)
6
IEEE 802.16e
Newly developed broadband wireless communication technology
MSS is battery-powered An effective power-saving strategy
is necessary for extending the operation time
Periodically turn off the transceiver to save power (Sleep Mode)
7
IEEE 802.16e MAC protocol Frequency division duplex (FDD) mode and
time division duplex (TDD) mode Downlink: from the BS to MSSs
Point-to-multipoint broadband wireless access Uplink
Multiple MSSs share one slotted uplink channel via TDD on a demand basis for voice, data, and multimedia traffic
The BS handles bandwidth allocation by assigning uplink slots based on requests from MSSs
8
IEEE 802.16e Service classes
Unsolicited Grant Service (UGS) Real-Time Polling Service (rtPS) Non-Real-Time Polling Service (nrtP
s) Best Effort (BE)
IEEE 802.16e IEEE 802.16m (1Gbps, 4G)
9
IEEE 802.16m Service classes
Real-time constant bit-rate (e.g., VoIP without silence suppression) Extended real-time variable bit-rate (e.g., VoIP with silence suppression) Real-time variable bit-rate (e.g., MPEG video) Non-real time variable bit-rate (e.g., FTP, HTTP) Best effort (e.g., E-mail)
RT-CBR ERT-VR RT-VRNRT-VR
BE
Data generated interval
Periodic Periodic PeriodicDynami
cDynami
c
Packet size FixedFixed/
dynamicDynami
cDynami
cDynami
c
Delay sensitivity
High High High Middle Low
10
Power Saving Techniques (1) Application layer
Load partitioning (computation performed at BS)
Reduce # of transmissions for operations (e.g. via data compression)
Transport layer Reduce # of retransmissions
Network layer Power efficient routing through a multi-hop
network
11
Power Saving Techniques (2) Data link layer
Reduce # of packet errors at a receiving node
Automatic Repeat Request (ARQ) and Forward Error Correction (FEC)
MAC layer Sleep scheduling protocols Cycle the radio between its on and off
power states
Physical layer Proper hardware design techniques
12
IEEE 802.16e Power Saving Three types of Power Saving Class (PSC)
Type I: MSS doubles its next sleep period if no packets are sent or received
Type II: MSS repeats the sleeping and listening periods in a round-robin fashion
Type III: MSS sleeps for the predefined period and then returns to normal operation
13
IEEE 802.16e Type I PSC
14
IEEE 802.16e Type II PSC
15
IEEE 802.16e Type III PSC
16
IEEE 802.16m Type IV PSC
17
IEEE 802.16m PSC
18
Related Work (1) Performance analysis (mainly PSC Type I)
For downlink traffic by semi-Markov chain (IEEE Comm. Mag. 2005)
For downlink & uplink by Poisson traffic pattern (IEEE Comm. Mag. 2006)
Hyper-Erlang distributed inter-arrival time (IEEE WCNC 2007)
Optimal selection of PSC I and II (IEEE WCNC 2007)
19
Related Work (2)
Adaptive power saving mechanisms Adjusting the waiting time before enterin
g the sleep mode Adjusting the initial and final sleep windo
ws (IEEE Globecom 2006) Delay-based sleep scheduling Latest enhancements (IEEE Trans. VT 2009, 2
010)
20
Load-based Power Saving Weakness of PSC I and PSC II
Exponential increase or constant pattern Traffic modeling and Measurement
Poisson arrival process (uplink & downlink) MSS’s load sleep cycle length
Data accumulation threshold (1 time frame) BS responsible for sleep schedule
21
LBPS in light load
22
LBPS in heavy load
23
LBPS-Aggr Protocol
24
LBPS Mathematics (1)
25
LBPS Mathematics (2)
Data_TH = one time frame of data
Prob_TH = 0.8 in the simulation
26
Problem with LBPS-Aggr Unrealistic assumption of synchronize
d sleep cycle for all MSSs Low utilization of mini-slots in a time f
rame Two enhancements
LBPS-Split LBPS-Merge
27
LBPS-Split Protocol (1)
28
LBPS-Split Protocol (2)
29
Features of LBPS-Split
Dividing MSSs to separate groups All MSSs with the same length (K*) of t
he sleep cycle Is it possible to use different value of
K* for different MSS? LBPS-Merge Schedulability for different K*
30
LBPS-Merge Protocol (1)
2
31
LBPS-Merge Protocol (2)
32
Simulation Study
# of MSS (one BS) 10, 20, 40, 80
# of mini-slots in a time frame 160
Value of Prob_TH 0.8
Packet size 1 mini-slot
Simulation time 1*107 time frames
Type I initial sleep interval 20 time frames
Type I maximal sleep interval 29 time frames
Length of listening window 1 time frame
Load distribution among MSS Equal, 8:2, Random
33
Performance Criteria
Power Saving Efficiency (PSE)
PSE = (K-1)/K
Access delay
K-1 time frames 1 time frame
K time frames
S A
S ASleep_window size Awake_window size
... ...
34
Power Saving Efficiency (1)
10 MSSs, Equal Load
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95Total load
Pow
er S
avin
g E
ffic
ienc
y
LBPS-Split LBPS-Merge LBPS-Aggr Standard Type I
35
Power Saving Efficiency (2)
10 MSSs , 8:2 Load
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95
Total load
Pow
er S
avin
g E
ffic
ienc
y
LBPS-Split LBPS-Merge LBPS-Aggr Standard Type I
36
Access Delay (1)10 MSSs, Equal Load
0
5
10
15
20
25
30
35
40
45
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95Total load
Del
ay (
time
fram
e)
LBPS-Split LBPS-Merge LBPS-Aggr Standard Type I
37
Access Delay (2)10 MSSs, 8:2 Load
0
5
10
15
20
25
30
35
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95Total load
Del
ay (
tim
e fr
ame)
LBPS-Split LBPS-Merge LBPS-Aggr Standard Type I
38
LBPS-Split: Impact of # MSS (1)
LBPS-Split, Equal Load
00.10.20.30.40.50.60.70.80.9
1
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95Total load
PS
E
10 MSSs 20 MSSs 40 MSSs 80 MSSs
39
LBPS-Split: Impact of # MSS (2)
LBPS-Split, 8:2 Load
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95Total load
PS
E
10 MSSs 20 MSSs 40 MSSs 80 MSSs
40
LBPS-Merge: Impact of # MSS (1)
LBPS-Merge, Equal Load
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95Total load
PSE
10 MSSs 20 MSSs 40 MSSs 80 0 MSSs
41
LBPS-Merge: Impact of # MSS (2)
LBPS-Merge, 8:2 Load
00.10.20.30.40.50.60.70.80.9
1
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95Total load
PSE
10 MSSs 20 MSSs 40 MSSs 80 MSSs
42
Impact of load distribution (1)
LBPS-Split, 10MSSs
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95Total load
PS
E
Equal Load 8:2 Load Random
43
Impact of load distribution (2)
LBPS-Merge, 10MSSs
00.10.20.30.40.50.60.70.80.9
1
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.95Total load
PS
E
Equal Load 8:2 Load Random
44
Conclusion & Future Work
Load-Based Power Saving Traffic Modeling & Measurement LBPS-Aggr, LBPS-Split, LBPS-Merge Better power saving efficiency
Future work Integrated real-time and non-real-time More general traffic modeling