1. Student : Sih-Han Chen Advisor : Ho-Ting Wu Date : 2008.5.6
IEEE WiMAX中頻寬 資源管理架構之研究 A Study of the Bandwidth Management Architecture over IEEE WiMAX
Student : Sih-Han Chen
Advisor : Ho-Ting Wu
Date :

2. Outline Introduction of IEEE802.16 and QoS
Proposed QoS System Architecture
Pairing Call Admission Control
Bandwidth Borrowing on CAC level
Two Stage Bandwidth Allocation
Mandatory Packet Scheduling Algorithm
Performance Evaluation
Conclusion and Future Work
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3. Worldwide Interoperability for Microwave Access(WiMAX)
Bandwidth
IEEE IEEE IEEE GPP
1 Gbps
High Speed
Wireless
PAN
Wi-Fi
802.11n
100 Mbps
WiMAX
802.16 (
& e)
Wi-Fi
802.11a/b/g
10 Mbps 4G 3G
2.5G
MAN Network
75Mbps 7 to 10KM
Max range 50km
微波存取全球互通
1 Mbps
Bluetooth
<1m m m Up to 50Km Up to 80Km
PAN
LAN
MAN
WAN
PAN: Personal area networks MAN: Metropolitan area networks
LAN: Local area networks Wide area networks
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4. IEEE Operation Mode
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5. MAC Common Part Sublayer
Defines multiple-access mechanism
Functions ：
connection establishment
connection maintenance
Call admission control
bandwidth request
bandwidth allocation
Packet shceduling
MAC Common Part Sublayer
(MPC)
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6. IEEE 802.16 TDD frame structure
TDM mode
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7. DL-MAP and UL-MAP 5/6/2008 ※Downlink subframe & uplink subframe
※BS send DL&UL MAP
※DL MAP
※UL MAP
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8. Media Acces Control (MAC)
Connection orienteded
Service Flow(SF)
Connection ID (CID)
Channel access:
UL-MAP
Defines uplink channel access
Defines uplink data burst profiles
DL-MAP
Defines downlink data burst profiles
UL-MAP and DL-MAP are both transmitted in the beginning of each downlink subframe (FDD and TDD).
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9. Bandwidth Request SSs may request bandwidth in 3 ways:
Contention-based bandwidth requests (Broadcast Polling or Multicast Group Pollng)
Contention-free bandwidth requests (Unicast Polling)
Piggyback a BW request message on a data packet
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10. Bandwidth Allocation BS grants/allocates bandwidth in one of two modes
Grant Per Subscriber Station (GPSS)
Grant Per Connection (GPC)
Decision based on requested BW, QoS parameters and available resources
Grants are realized through the UL-MAP
在BS中spec提供了2種 分配頻寬 的模式
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11. Service Classes Feature Application UGS Real Time Constant Bit Rate
(Unsolicited Grant Service)
Real Time
Constant Bit Rate
T1/E1
VoIP
rtPS
(Real-Time Polling Service)
Variable Bite Rate
MPEG video
nrtPS
(Non-Real-Time Polling Service)
Non-Real Time
FTP BE
(Best Effort)
No QoS guarantee
HTTP
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12. Service Flow The central concept of the MAC protocol
A service flow is a unidirectional flow of packets that is provided a particular QoS.
SS and BS provide this QoS according to the QoS parameter set.
Existing in both uplink and downlink and may exist without being activated.
Must have a 32bit SFID, besides admitted and active status also have a 16-bit CID
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13. Attributes of a Service Flow
Relationship of QoS Parameter Set
Service Flow ID
CID
ProvisionedQoSParamSet
AdmittedQoSParamSet
ActiveQoSParamSet
Authorization Module
ProvisionedQoSParamSet
(SFID)
AdmittedQoSParamSet
(SFID & CID)
ActiveQoSParamSet
(SFID & CID)
一個service flow 至少要有一個SFID和相關聯的方向，主要當作BS與SS間中眾多service flow的識別號碼
只有service flow 在admitted or active狀態時才會有CID存在
由網路管理系統提供的QoS參數，不在 標準規範內, A set of external QoS parameters provided to the MAC, For example by the nerwork management system.
BS也可能是SS會根據此參數來做頻寬的保留
根據此QoS參數集，來真正提供Service Flow傳輸服務，只有Active Service Flow可以傳送封包
是一個在BS內部的邏輯功能模組，主要用來判斷是否同意或是拒絕QoS參數的改變，也負責規定Admitted QoS Parameter Set 與 Active QoS Parameter Set可能的值。
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14. Dynamic Service Management
Dynamic Service Add (DSA)
Add a service flow
Dynamic Service Change (DSC)
Change an existing service flow
Dynamic Service Delete (DSD)
Delete a service flow
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15. Dynamic Service Establishment
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16. Outline Introduction of IEEE802.16 QoS
Proposed QoS System Architecture
Pairing Call Admission Control
Bandwidth Borrowing on CAC level
Two Stage Bandwidth Allocation
Mandatory Packet Scheduling Algorithm
Performance Evaluation
Conclusion and Future Work
5/6/2008

17. Proposed QoS ArchitectureBS SS
Connection Request
Pair Call Admission Control
Bandwidth
Borrowing
Agent
Applications
Core Network
Connection Response
Uplink
Data Traffic
Downlink
Data Traffic
UGS
rtPS
nrtPS BE
UGS
rtPS
nrtPS BE
Two Stage
Bandwidth Allocation
Two Stage
Bandwidth Allocation
Down Stream
(DL/UL MAP)
Downlink Packet Scheduler
Uplink Packet Scheduler
Up Stream
(Bandwidth Request)
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18. Outline Introduction of IEEE802.16 QoS
Proposed QoS System Architecture
Pairing Call Admission Control
Bandwidth Borrowing on CAC level
Two Stage Bandwidth Allocation
Mandatory Packet Scheduling Algorithm
Performance Evaluation
Conclusion and Future Work
5/6/2008

19. Pairing Call Admission Control
Symbol
Definition
Total System Bandwidth Resource
Remaining Available System Bandwidth Resource
Connection Request
Peak Traffic Rate of Connection Request, ( X = DL or UL)
Average Traffic Rate of Connection Request, ( X = DL or UL)
Min Traffic Rate of Connection Request, ( X = DL or UL)
Reserved Bw for Connection, ( X = DL or UL)
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20. Pairing Call Admission Control
Each Pair
Connection
Request
Bavailable >= Y
Is UGS? Y N
Accept
Pair Call Y
Is rtPS? N N
Enable
Bandwidth
Borrowing ? Y Y
Is nrtPS? Go
Bandwidth Borrowing
Agent N N Y
Is BE?
Reject Call
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21. Outline Introduction of IEEE802.16 QoS
Proposed QoS System Architecture
Pairing Call Admission Control
Bandwidth Borrowing on CAC level
Two Stage Bandwidth Allocation
Mandatory Packet Scheduling Algorithm
Performance Evaluation
Conclusion and Future Work
5/6/2008

22. Bandwidth Borrowing Flow Chart
Pair Connection Request from CAC Module
Success
Borrow
from existing
BE Cons
Fail Y
Is UGS?
Reject
Accept N
Success
Success
Success
Borrow
from existing
BE Cons
Borrow
from existing
nrtPS Cons
Borrow
from existing
rtPS Cons
Fail
Fail
Fail Y
Is rtPS?
Reject
Accept N
Success
Success
Borrow
from existing
BE Cons
Borrow
from existing
nrtPS Cons
Fail
Fail Y
Reject
Is nrtPS? N Y
Is BE?
Reject
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23. Bandwidth Borrowing on CAC Level
Symbol
Definition
Total numbers of rtPS , nrtPS or BE connection in system(X = rtPS , nrtPS or BE)
The current reserved bandwidth for connection i
The low bound of reserved bandwidth for connection i.
Amount of bandwidth are needed to be borrowed from system.
In system, How many bandwidth can be borrowed from rtPS, nrtPS and BE individually.
(X = rtPS , nrtPS or BE )
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24. Range of Bandwidth Reservation
Rsv-nrtPS
Rsv-rtPS
Rsv-UGS
Rsv-BE
(Average+Min) /2
(Peak+Average) /2
Min/2
Average
Rate
Peak
Rate
Min
Rate
Rsv-nrtPS
Low Bound
Rsv-BE
Low Bound
Rsv-rtPS
Low Bound
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25. Operation of Bandwidth Borrowing
Amount of bandwidth are needed to be borrowed from system
In system, the bandwidth can be borrowed from rtPS, nrtPS and BE individually
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26. Operation of Bandwidth Borrowing
If , the bandwidth borrowing from each exiting BE connection：
Else, try to borrow bandwidth from nrtPS.
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27. Operation of Bandwidth Borrowing
If , the bandwidth borrowing from each exiting nrtPS connecion, after borrow from all ：
Else, try to borrow bandwidth from rtPS.
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28. Operation of Bandwidth Borrowing
If ,the bandwidth borrowing from each exiting rtPS connecion, after borrow from all and and ：
Else, Bandwidth Borrowing Fail ! Reject the connection request.
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29. Outline Introduction of IEEE802.16 QoS
Proposed QoS System Architecture
Pairing Call Admission Control
Bandwidth Borrowing on CAC level
Two Stage Bandwidth Allocation
Mandatory Packet Scheduling Algorithm
Performance Evaluation
Conclusion and Future Work
5/6/2008

30. Two Stage Bandwidth Allocation
Stage One：
Give the guarantee reserved bandwidth at most.
Obtain fairness, guarantee each connection shares the bandwidth
Stage Two ：
Allocate the remaining bandwidth.
Partial fairness. Use weighting ( i.e. rtPS:nrtPS:BE = 2:1:1 ) to share the bandwidth.
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31. Two Stage Bandwidth Allocation
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32. Outline Introduction of IEEE802.16 QoS
Proposed QoS System Architecture
Pairing Call Admission Control
Bandwidth Borrowing on CAC level
Two Stage Bandwidth Allocation
Mandatory Packet Scheduling Algorithm
Performance Evaluatioin
Conclusion and Future Work
5/6/2008

33. Mandatory Packet Scheduling Algorithm
Scheduling Service
Mandatory Algorithm
UGS
First In First Out (FIFO)
rtPS
Earliest Deadline First (EDF)
nrtPS
Weighted Fair Queue (WFQ) BE
Round Robin (RR)
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34. Outline Introduction of IEEE802.16 QoS
Proposed QoS System Architecture
Pairing Call Admission Control
Bandwidth Borrowing on CAC level
Two Stage Bandwidth Allocation
Mandatory Packet Scheduling Algorithm
Performance Evaluation
Conclusion and Future Work
5/6/2008

35. Traffic Generation and Simulation Environment
Values
Number of BS 1
Number of SS
Total Bandwidth
64 Mbps
Each SS Data Source
4 (UGS/rtPS/nrtPS/BE)
Total Simulation Time
1000 Seconds
Frame Duration
10 ms
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36. System Model of Simulation Experiment
Note : We assume that only SS can send the connection request to BS actively
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37. Traffic Generation and Simulation Environment
UGS
rtPS
nrtPS BE
Application
VoIP
Video Stream
FTP
Average Data Rate
64 Kbps
DL：387Kbps
UL：38.7Kbps
DL：320Kbps
UL：32Kbps
192 Kbps
Maximum Sustained Traffic Rate
DL：464.4Kbps
UL：46.44Kbps
DL：384Kbps
UL：38.4Kbps
230.4Kbps
Minimum Reserve Traffic Rate
DL：309.6Kbps
UL：30.96Kbps
DL：256Kbps
UL：25.6Kbps
153.6Kbps
Accept Call Criteria
Max Rate
64Kbps
(Max+Avg)/2
DL：425.7Kbps
UL：42.57Kbps
(Avg+Min)/2
DL：288Kbps
UL：28.8Kbps
Min / 2
76.8Kbps
Low Bound of Guarantee Bw
Avg Rate
Min Rate
Call Inter Arrival Time
9 Seconds
Exponential
37.5 Seconds
30 Seconds
4.5 Seconds
Call Duration
240 seconds
60 seconds
30 seconds
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38. Traffic Generation and Simulation Environment
UGS
rtPS
nrtPS BE
Maximum Latency
20 ms
40 ms
100 ms
200 ms
Schedule Scheme
FIFO
EDF
WFQ RR
Packet Size
160 Bytes
Fixed-Size
Bytes
Uniform
Packet Fragment
80 Bytes
240 Bytes
120 Bytes
Packet Inter Arrival Time
Fixed Period
DL : ms
UL : 163.5ms
DL：20 ms
UL：200ms
33ms
Reserve Bw
Per frame
(Non Bandwidth Borrowing)
DL： B
UL： B
DL：360 B
UL：36 B
96 Bytes
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39. Performance Metric Call Blocking Probability : Packet Drop Rate :
Packet Delay :
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40. NonPairing CAC vs Pairing CAC
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41. Definition of Pairing CAC
Accepted :
Reject :
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42. Definition of NonPairing CAC Accept Call
Round Trip Time of Downlink Connection Request (RTT)
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43. Definition of NonPairing CAC Reject Call
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44. Definition of NonPairing CAC
Default RTT of DL connection request
： 0.5 seconds
Accepted :
First Type of Connection Fail :
Second Type of Connection Fail :
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45. Call Blocking Probability NonPairing CAC vs Pairing CAC
RTT = 0.5s
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46. Call Blocking Probability- Pair vs NonPair (RTT=0.5)
UGS
rtPS
nrtPS BE
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47. Accept Calls - Pairing vs NonPairing (RTT= 5s, 10s)
UGS
rtPS
nrtPS BE
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48. In Pairing CAC Mode Non Bandwidth Borrowing (NonBB) vs Bandwidth Borrowing (BB)
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49. Bandwidth Borrowing Scheme
Service Type
Bandwidth Borrowing Scheme
UGS BE
rtPS
BE  nrtPS  rtPS
nrtPS
BE  nrtPS
Non
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50. Call Blocking Probability NonBB vs BB
NonBB mode
BB mode
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51. Call Blocking Probability- BB vs NonBB
UGS
rtPS
nrtPS BE
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52. Overall Packet Drop Rate NonBB vs BB
NonBB mode
BB mode
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53. NonBB Mode DL and UL Packet Drop Rate
Downlink
Packet Drop
NonBB Mode
Uplink
Packet Drop
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54. BB Mode DL and UL Packet Drop Rate
Downlink
Packet Drop
BB Mode
Uplink
Packet Drop
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55. Overall Packet Delay NonBB vs BB
BB mode
NonBB mode
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56. NonBB Mode DL and UL Packet Delay
Downlink
Packet Delay
NonBB Mode
Uplink
Packet Delay
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57. BB Mode DL and UL Delay BB Mode Downlink Packet Delay BB Mode Uplink
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58. Conclusion Proposed a novel QoS architecture over Wimax, including :
Pairing Call Admission Control (CAC)
Bandwidth Borrowing on CAC level
Two Stage Bandwidth Allocation
Both Downlink and Uplink dynamic bandwidth allocation.
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59. Thanks for your attention
Q&A
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60. Pairing Call Admission Control
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61. Future Works Design a dynamic packet fragment scheme
Provide a queuing algorithm for non-real time service (nrtPS and BE).
Cross-layer design for specific popular application (i.e. adjust VoIP or IPTV codex) .
Extend to Mobil WiMAX (IEEE e)
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62. Bandwidth Reservation Scheme
Basic Bandwidth Reserved Scheme
Analysis
Maximum Sustained Traffic Rate
( = Peak Rate)
每條被允入的連線都能達到100 %服務品質保證。
系統所允入的連線數目最少，且頻寬的使用率也是最低。
對於Variable Bit Rate類型的連線，有較嚴重的頻寬浪費。
適合用於Constant Bit Rate 類型的連線。
Average Traffic Rate
定義上，長期(Long term)時間內能滿足各連線的需求，但短期內無法達到100 % 的服務品質保證。
被允入的連線數目提高，且能提供一定品質的服務。
對於有時效性的連線封包，在突爆量時封包的丟棄率(Drop rate)會稍高。
Minimum Reserved Traffic Rate
( = Min Rate)
只能提供每條連線最小保留頻寬的服務。
被允入的連線數目最多，但每條連線都只享有最低的服務品質，可能造成過長的時間延遲問題。
較適合沒有時效性的連線。
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63. IEEE 802.16 QoS Provisioning Service Flow QoS Scheduling
Dynamic Service Establishment
Two-phase Activation
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