broadband mobile wireless network lab quality of service scheduling for 802.16 broadband wireless...
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Broadband Mobile Wireless Network Lab
Quality of Service Scheduling for 802.16 Broadband Wireless Access Systems
Vehicular Technology Conference, 2006. VTC 2006-Spring. IEEE 63rd
Jonny SUN, Yanling YAO, Hongfei ZHU
Advanced System Technology Telecom Lab (Beijing)
STMicroelectronics
Beijing CHINA
Presenter ： Pao-Wei Hwang
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Abstract
IEEE 802.16 support heterogeneous classes of traffic with
differentiated Quality of Service (QoS).
In this paper, a new and efficient QoS scheduling strategy based on the hierarchical and distributed architecture is proposed for 802.16 Broadband Wireless Access (BWA) systems.
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Outline
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I. INTRODUCTION
II. IEEE 802.16 BWA SYSTEMS
III. QoS SCHEDULING FOR 802.16 SYSTEMS
IV. SIMULATION MODEL AND RESULT ANALYSIS
V. CONCLUSION
I. INTRODUCTION
Medium Access Control (MAC) bandwidth allocation mechanisms
• UGS : Constant Bit Rate ( CBR )
• real-time : Variable Bit Rate ( VBR )
• Nonreal-time : Nonreal-time VBR
• Best Effort
MAC protocol does not include a complete solution for how to efficiently schedule traffic to fulfill the QoS requirements.
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II. IEEE 802.16 BWA SYSTEMS
IEEE 802.16d point-to-multipoint (PMP)
• In downlink, from BS to SS– BS is the unique transmitter broadcasting to all the SSs
• In uplink,from SS to BS– BS is shared by all the SSs on a demand basis.
Mesh
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III. QoS SCHEDULING FOR 802.16 SYSTEMS
how to efficiently schedule different types? propose a QoS scheduling strategy based on the
hierarchical and distributed architecture.• A. QoS Scheduling Architecture for 802.16 Systems
• B. Scheduling Algorithm at BS
• C. Scheduling Algorithm at SS
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III. QoS SCHEDULING FOR 802.16 SYSTEMS
B. Scheduling Algorithm at BS
Define two types of queue Type (I) queue Type(II) queue
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A. QoS Scheduling Architecture for 802.16 Systems
Type I queue UGS
• Guarantee grants to be scheduled without interrupt
• First-in First-out (FIFO)
III. QoS SCHEDULING FOR 802.16 SYSTEMS
Type II queue rtPS ， nrtPS ， and BE
fair queuing algorithm that consists of two phases: minimum reserved bandwidth assurance excess bandwidth distribution.
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connection by the demandedcurrently bandwidth :
i connectionfor bandwidth reserved minimum the:
i queue connection toallocatedbandwidth reserved minimum :
(1) } , min{
BRBb
BRBb
i
MIN
i
MIN
i
i
MIN
i
MIN
i
III. QoS SCHEDULING FOR 802.16 SYSTEMS
Fairness to distributing excess bandwidth
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packet :k
i queue connection of weight the:
i queue connection toallocatedbandwidth excess ofamount the:
bandwidth excess the:
bandwidth available total the:
(3)
(2) -B
kw
BB
wB
B
th
i
EX
k
iEX
i
EX
b
wb
b
EX
i
k
EX
i
MIN
i
III. QoS SCHEDULING FOR 802.16 SYSTEMS
C. Scheduling Algorithm at SS Scheduling algorithm for UGS queues Scheduling algorithm for rtPS queues Scheduling algorithm for nrtPS queues Scheduling algorithm for BE queues
At SS Priority of scheduling service
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III. QoS SCHEDULING FOR 802.16 SYSTEMS
Scheduling algorithm for UGS queues Critical delay Critical delay jitter Firstly guarantee the bandwidth
Scheduling algorithm for rtPS queues Should meet tight delay bound Each packet of rtPS should be mark a deadline stamp
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flow serviceeach for Latency Maximum：
timearrival：
delaytolerated
t
delaytoleratedtStampDeadline
III. QoS SCHEDULING FOR 802.16 SYSTEMS
Scheduling algorithm for nrtPS queues Target at maintaining throughput Each packet with a virtual time stamp
Scheduling algorithm for BE queues There is no QoS guarantee required A simple FIFO mechanisms is applied
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IV. SIMULATION MODEL AND RESULT ANALYSIS
NS2 PMP MAC operation TDD-OFDM One BS and 20 SSs
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SS UGS rtPS nrtPS BE
First 1 1 1 1
Second 1 1 1 1
Third 1
Fourth 1
Fifth 1
Other 1
IV. SIMULATION MODEL AND RESULT ANALYSIS
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V. CONCLUSION
A new and efficient QoS scheduling strategy based on the hierarchical and distributed architecture is proposed to provide differentiated level of QoS guarantees to various application.
BS scheduler
Guarantee the minimum bandwidth for each service flow SS scheduler
provide differentiated and flexible QoS support for all of the four scheduling service types
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