1 a flexible bandwidth management scheme in bluetooth chin-fu liu multimedia and communications...
TRANSCRIPT
1
A Flexible Bandwidth Management Scheme
in Bluetooth
Chin-Fu LiuMultimedia and Communications LaboratoryDepartment of Computer Science and Information EngineeringNational Chi Nan UniversityTaiwan, R.O.C.
Advisor : Chun-Chuan Yang
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Outline
Introduction Basic Version of Bandwidth-Based Polling
(BBP-bas) Scheme Extended Version (BBP-ext) Scheduling algorithm for BBP-ext Performance Evaluation Conclusion
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Introduction - Bluetooth
Low cost Low complexity In a small area Piconet
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Introduction
Time Division Duplex
Master based polling
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Introduction
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Introduction – QoS Support in BT.
Goals of bandwidth management1.Bandwidth satisfaction2.Fairness
Goal of Bandwidth-Based Polling (BBP) 1.Bandwidth management2.Minimal Control signaling3.Lower Jitter on SCO links
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BBP notation
QoS-slave SCO-slave BE-slave (best effort slaves)
BBP-bas
BBP-ext
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Bandwidth Based Polling Scheme - Basic version
Basic idea and slots allocation for QoS slaves
Framing structure of time slots Dynamic frame for flexibility Polling many times
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Bandwidth Based Polling Scheme - Basic version
Basic idea and slots allocation for QoS slaves
DH11 = DH5+DH5+DH1 DH5 > DH3 >> DH1 Maximum polling times
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Bandwidth Based Polling Scheme - Basic version
Basic idea and slots allocation for QoS slaves
Progressive bandwidth allocation
Negotiation process
MasterSlavei
(BwRqi)
PicoFrameSize & PicoFrameLimit
RequestSlot & Framelimit
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Bandwidth Based Polling Scheme - Basic version
QoS slave actions
#Bytesi = BwRQi * PicoFrameLimit * 625μs Payload type :
ByteCount >= #Bytesi or DH5*K
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Bandwidth Based Polling Scheme - Basic version
QoS slave actions
FrameLimiti=(RequestSloti Byte#)/(BwRQi*625μs)
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Bandwidth Based Polling Scheme - Basic version
Master actions
PicoFrameSize - by RequestSloti
PicoFrameLimit - by FrameLimiti
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Bandwidth Based Polling Scheme - Extended version
Support SCO-Slave
SCO link - Isochronous service by TSCO
HV3 TSCO=6 (64Kbps CBR service)
Adaptive TSCO
Ex:TSCO =16 (24Kbps) Soft SCO links - Jitters due to shifting
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Bandwidth Based Polling Scheme - Extended version
Support SCO-Slave
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Bandwidth Based Polling Scheme - Extended version
Support Best Effort Slave (BE-Slave)
Equilibrium state Unused Slots = PicoFrameLimit - PicoFrameSize Slots quantum = (PFL-PFS)/(# of BE-slaves)
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Bandwidth Based Polling Scheme - Extended version
Packet format in BBP-Ext
Original Packet
Master→QoS slave
QoS slave→Master
Master→BE slave
BE slave→Master
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Scheduling algorithm for BBP-ext
Scheduling all kinds of slaves
Round RobinS1=DH3 S2=DH8 S3=DH10 TSCO=10
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Scheduling algorithm for BBP-ext
Delay/Jitter analysis
Reasons for shifting:(1) Undividable packet
of QoS-slave (2) Other SCO-slaves
Maximum shift → 4+(N-1)*2 Slots Tsniff=TSCO
Nsniff-attempt=Maximum shift
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Performance Evaluation
Simulation Env & Performance Criteria
1 slot=625μs Bandwidth utilization Fairness and flexibility with QoS slaves Maximum shift in SCO links
(Kbps) Slave 1 Slave 2 Slave 3 Slave 4 Slave 5 Slave 6 Slave 7 Remarks
Test case 1 50 75 100 125 150 175 N/A 6 QoS
Test case 2 50 75 100 125 150 Tsco=10 N/A 5 QoS, 1 SCO
Test case 3 50 100 150 200 Tsco=10 BE N/A 4 QoS, 1 SCO, 1 BE
Test case 4 50(0 ~ 2s)
75(0 ~ 2s)
200(0 ~ 2s)
150(0 ~ 2s)
100(0 ~ 2s)
150(0 ~ 1s)
N/A Slave 6 leaves early
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Performance Evaluation
Simulation Result & DiscussionK=4 Req=150K
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Performance Evaluation – Case 1
Simulation Result & DiscussionK=1
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Performance Evaluation – Case 1
Simulation Result & DiscussionK=4
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Performance Evaluation - Case 2
Simulation Result & DiscussionK=4 TSCO=10
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Performance Evaluation – Case 3
Simulation Result & DiscussionK=4 TSCO=10
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Performance Evaluation – Case 4
Simulation Result & Discussion
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Performance Evaluation
Simulation Result & Discussion
K=1 K=2
K=4 K=8
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Conclusion
A dynamic framing structure Distributed Mechanism Minimal Control signaling Good performance and flexibility by BBP Future Work
Master’s request Admission controlBluetooth 2.0