adviser: ho-ting wu speaker: lei yan 1. + introduction to ieee 802.16 and qos + proposed power...

Adviser: Ho-Ting WuSpeaker: Lei Yan

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+ Introduction to IEEE 802.16 and QoS+ Proposed power saving mechanism

– Motivation– Related works– Proposed bandwidth allocation algorithm– Proposed packet scheduling algorithms

+ Simulation results+ Conclusion and future works

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[1] IEEE 802.16d-2004 and IEEE 802.16e-2005 Std.[2]張致恩 . 無線都會網路系統與技術短期課程 . 中原大學電子系 .

2008[3] Min-Gom Kim, Minho Kang, and Jung Yul Choi, “Performance Evaluation

of the Sleep Mode Operation in the IEEE 802.16e MAC,” Advanced Communication Technology, The 9th International Conference. Publication Date: 12-14 Feb. 2007 Vol. 1, pp. 602-605

[4] Kwanghun Han and Sunghyun Choi, “Performance Analysis of Sleep Mode Operation in IEEE 802.16e Mobile Broadband Wireless Access Systems,” Vehicular Technology Conference, 2006. VTC 2006-Spring. IEEE 63rd Volume 3, 2006 Page(s):1141 – 1145

[5] Shengqing Zhu, Xiaoyu Ma, and Lujian Wang, “A Delay-aware Auto Sleep Mode Operation for Power Saving WiMAX,” Computer Communications and Networks, 2007. ICCCN 2007. Proceedings of 16th International Conference on 13-16 Aug. 2007 Page(s):997 - 1001

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[6] Yan Zhang, “Performance Modeling of Energy Management Mechanism in IEEE 802.16e Mobile WiMAX,” Wireless Communications and Networking Conference, 2007.WCNC 2007. IEEE 11-15 March 2007 Page(s):3205 - 3209

[7] Min-Gon Kim, JungYul Choi, and Minho Kang; “Adaptive power saving mechanism considering the request period of each initiation of awakening in the IEEE 802.16e system,”Communications Letters, IEEE Volume 12, Issue 2, February 2008 Page(s):106 - 108

[8] Sanghvi, K., Jain, P.K., Lele, A., and Das, D., “Adaptive waiting time threshold estimation algorithm for power saving in sleep mode of IEEE 802.16e,” Communication Systems Software and Middleware and Workshops, 2008. COMSWARE 2008. 3rd International Conference on 6-10 Jan. 2008 Page(s):334 - 340

[9]邱元甫 . 應用於 IEEE 802.16網路之整合性節能排程演算法 (IPSS: Integrated Power Saving Scheduling Algorithm for IEEE 802.16 PMP Networks). 國立成功大學電腦與通信工程研究所碩士論文 . July, 2008

[10] Shih-Chang Huang, Rong-Hong Jan, and Chien Chen, “Energy efficient scheduling with QoS guarantee for IEEE 802.16e broadband wireless access networks,” Proceedings of the 2007 international conference on Wireless communications and mobile computing, pp. 547-552

[11] Chia-Yen Lin and Hsi-Lu Chao, “Energy-saving scheduling in IEEE 802.16e networks,” 14-17 Oct. 2008 Page(s):130 - 135

[12] Chun-Hung Chen, Ho-Ting Wu, and Kai-Wei Ke, ”Predictive Credit Based Dynamic Bandwidth Allocation Mechanisms in Ethernet Passive Optical Network,”, TENCON 2006. 2006 IEEE Region 10 Conference, 14-17 Nov. 2006 Page(s):1 - 4

+ Introduction to IEEE 802.16 and QoS+ Proposed power saving mechanism

– Motivation– Related works– Proposed BWA algorithm– Proposed packet scheduling algorithms

+ Simulation results (Unfinished)+ Conclusion and future works

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+ Also called “WiMAX” (Worldwide Interoperability for Microwave Access)

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Wi-Fi802.11a/b/g

802.15.1Bluetooth

802.15.3High Speed

WirelessPAN Wi-Fi

802.11n

Bandwidth 1

Gbps

100 Mbps

10 Mbps

1 Mbps

PAN LAN MAN WAN<1m 10m 100m Up to 50Km Up to 80Km

WiMAX802.16

(802.16-2004 & 802.16e)

4G

3G

2.5G

IEEE 802.15 IEEE 802.11 IEEE 802.16 3GPP

PAN: Personal area networksMAN: Metropolitan area networks

LAN: Local area networks Wide area networks

+ PHY: S-OFDMA, MIMO, LDPC, and Space-Time Coding, etc+ Theoretical data rate and coverage: 75Mbps and 50km

+ Fixed (802.16d) and mobile (802.16e) for SS+ Latest version: 802.16m

+ Opponents in last-mile: DSL/FTTB/FTTH+ Opponent in the 4G candidate: LTE

+ Pros: HI data rate (good for HQ multimedia services!) and robust to Doppler spread

+ Cons: LO indoor penetration 8

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• Responsible for multiple-access control

• Functions ：– Connection establishment– Connection maintenance– Connection deletion– Call admission control (CAC)– Bandwidth request– Bandwidth allocation (BWA)– Packet scheduling

MAC Common Part Sublayer

(MPC)

Frame n-1 Frame n Frame n+1

DL Subframe UL Subframe

Preamble FCH DL-Burst #1

DL-Burst #2-4

DL-Burst #5

DL-Burst #6

TTG

RTG

Initialranging

BWrequest

UL-Burst #1

UL-Burst #2

DLFP DL-MAP UL-MAP MAC messages, Mac PDUs

IEIE IE IE IE IE IE IE IE IE

Preamble FCH DL-Bursts#1-4 DL-Burst #5 DL-Burst #6 RangingOpportunity

BWrequest

UL-Burst #1

UL-Burst #2

Preamble(optional)

MACPDU

MACPDU

Pad Preamble(optional)

MACPDU

MACPDU

Midamble(optional)

MACPDU

MACPDU

Pad

每個UL-Burst內的資料，都必須來自同一台SS每個DL-Burst內的資料，有可能是要送給不同SS

IE IE

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+ DL-MAP: BS lists the allocation time and size granted to MSs

+ UL-MAP: BS lists the order and size for BW requests by MSs

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+ Phase 1: After ranging, according to the need of upper layers, MS uplinks a connection (call) request to BS, the BS accepts/rejects this call via CAC

+ Phase 2: Although BW request is calculated by connections, BS grants data in the aspect of MS (packets granted in a batch) via BWA

+ Phase 3: After the need ends, MS drops the call12

+ 1. Packet scheduling: The way for some purpose for BS to ADAPTIVELY arrange DL/UL orders for MS (but the de facto algorithm is not defined)

+ 2. Power saving function: The way for MS to ADAPTIVELY turn-off its RF devices (to “sleep”) at proper time (but the de facto algorithm is not defined)

+ However, packet scheduling (BS initiated) can ALSO achieve power saving function (such as our research)!! 14

+ Reasons for power saving:– MASSIVE use of multimedia services runs out

the battery fast– The Tx/Rx power STILL costs a lot even though

AMC is applied

+ Initiation of power saving mode:– BS initiated (research after 2008, including ours)– MS initiated (research before 2008)

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+ Same type, different names!!

Service type Packet scheduling

Power saving Proposes

UGS UGS UGS VoIP

ertPS ertPS ERTVR VoIP (silence suppression)

rtPS rtPS RTVR MPEG

nrtPS nrtPS NRTVR FTP

BE BE BE HTTP

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+ The MS operation hierarchy in Std.:

+ In later pages we will modify the above17

MS operation

Normal mode (RF device ON)

Sleep mode (RF device OFF)

Sleep interval (RF device OFF)

Listening interval (RF device ON)

+ Three types of sleeping:– PSC I (HI delay bound): NRTVR and BE– PSC II (LO delay bound): UGS and RTVR– PSC III (LO delay bound): ERTVR

+ Q: Why ERTVR is listed in PSC III?+ A: The silence suppression function keeps this call

sleep longer18

Sleep mode (PSC I to III) is shown below:

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• The physical sleep time for MS is the intersection among its ALL calls (very short!)

+ Introduction to IEEE 802.16 and QoS+ Proposed power saving mechanism (PSM)

– Related works– Motivation– Proposed BWA algorithm– Proposed packet scheduling algorithms


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Categorize from [3] to [11]:Sleep time adaption in MS (only “guess”) [3-8]: MS

predicts WHEN BS grants data, so there exists delays between predicted and actual time

Scheduler categorizes MS by real-time/non real-time [9]: So MS cannot have BOTH

UGS only [10] and lack of ertPS [11]

Without BWA (except for [9])21




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+ Our design features:– Five service types (novelty)– A traditional CAC algorithm – A BWA algorithm for BS to ADAPTIVELY grants data– Three packet scheduling algorithms for power saving

+ Q: Why we don’t use the “separated” power saving func. from Std.?+ A: From p.19, we thus need an integrated alm. to CENTRALLY arrange

calls to prolong the MS sleep time.

+ Q: What is the benefit for above?+ A: Reduction of frequent state transitions (overshoot at MS start-up)

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+ We modify the Std.-defined hierarchy into only 2 states: ON-state (RF device ON) and OFF-state (RF device OFF)

MS operation

ON-state (RF device ON)

Sleep mode (RF device OFF)

OFF-state (RF device OFF)

Listening interval (RF device ON)

+ Because data is allowed to be scheduled across frames in our design, we need to lower packet delay for each call, thus we have to estimate the ON-state time by estimating grant size

+ Our scheduling algorithm allocates time for BR and BWA for the next scheduling cycle (>frame duration)

ON-state time for call A

ON-state time for call A

BR

MS

BS

timeScheduling cycle (determined by scheduling algoirithm)

BWA->grant

OFF-state for call AOFF-

state for call A

OFF-state for call A

+ Modified from [12], we wish to get a proper grant_size (Gk) at kth scheduling based on past experiences

+ Parameters:– Scheduling cycle (obtained from scheduling alm.)– buffer_size: Size in BS and requested by MS– grant_size: Size granted by BS– CAC_BW: The BW that this call requested in CAC– Credit: Used to fine-tune the grant_size– Estimated arrival rate during previous scheduling cycle 27

+ The BS sometimes NOT always grant sizes that a call exactly wants (so we use credit to +/- the grant size)

+ Formula (1): Credit (+/-) is obtained by estimating the arrival rate (BW) for previous scheduling cycle, under the case that BS has known all data sizes it should grant next time (we can transform it into the current scheduling cycle duration)

+ Formula (2): If the difference between buffer size is minus (the traffic flow is slowed down), then credit is minus

+ For rtPS/nrtPS/BE, the above criterions are applied

+ For UGS/ertPS in a scheduling cycle, the BWA grants size of 64kbps*scheduling_cycle_duration

+ Due to the constant transmission rate for UGS/ertPS, we can predict the scheduling cycle length much more precise than rtPS/nrtPS/BE




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+ Design criterion (MS-based):– Merge DL/UL time (for BR/BWA) to MS in ON-state– Frame overflow is allowed– No violation to the traffic delay bound– The OFF-state time is the sleep time for MS

+ Goal of the algorithms:– Simply “ON-state time” and “OFF-state time”– No drastic packet dropping rate– Prevent frequent ON-OFF switching (overshooting)– Efficiently utilize DL/UL resource

+ Delay bound by service type (ms):– DUGS– DertPS– DrtPS– DnrtPS– DBE

+ TSi is the sleep time of MSi+ Scheduling cycle: 屬於MS的某個 call其兩次排程間的間隔 ,依其型態而假設如下 :– [traffic]-cycle <= D[traffic]– For example, R-cycle<=DrtPS for rtPS traffics

Traffic 2Traffic

1

Frame duration

……

+ For any traffic, a call that firstly performs BR should be scheduled directly without computation of credits.

+ Criterion 1: Split time into U-cycles (with delay bound of DUGS). Always allocate UGS/ertPS calls in the front

+ Criterion 2: Allocate rtPS->nrtPS->BE for MS i into the remainder of U-cycle

+ Criterion 3: Once we can’t allocate data size inside one frame duration, allocate the rest at next frame (see p.33)

+ Criterion 4: As long as no violation for delay bound occurs, the remained data can be allocated in the next U-cycle

+ Criterion 5: Drop the rest if the scheduling exceeds the traffic delay bound

+ Periodic UGSi/ertPSi (mandatory)+ Guarantee no delay for UGSi/ertPSi+ Concentrate rtPSi/nrtPSi/BEi for MSi+ Packets after delay bound should be dropped

…U1-UM

N1 B1U1-UM

R1 N2 B2

U-cycle

… U1-UM

RM

U-cycle

U1-UM

RM N1

U-cycleN-cycle for MS1

U-cycle

R-cycle for MS1

B1E1-EM

R2E1-EM

R1E1-EM

Delay D <= U-cycleDelay D <= U-cycle

TS1 TS1

E1-EM




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+ Our novel research includes: 5 traffic types + CAC + BWA + Packet scheduling algorithms, which is more realistic than related works

+ Our BWA adaptively and smartly helps BS grant

+ The efficiency comparison among algorithms will be soon evaluated (packet dropping rate and sleep ratio, etc)

+ Really appreciate for your great comments!!

adviser: ho-ting wu speaker: lei yan 1. + introduction to ieee 802.16 and qos + proposed power...

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