WOMEN project: Traffic Control in a mesh IEEE802'11 network

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WOMEN projectTraffic Control in a mesh
IEEE802.11 network
University of Rome La Sapienza Tiziano
Inzerilli 19/1/2007
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Contents

• Models and basic assumptions
• Approach for QoS provision
• traffic control scheduler design
• Statistics

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Contents
MODELS BASIC ASSUMPTIONS

• Models and basic assumptions
• Approach for QoS provision channel state
  dependent scheduling
• Statistics

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Network model

• MRs (mobile routers) APs (access points)
• quasi static nodes
• Point-to-multipoint transmission
• IEEE802.16/ IEEE802.11
• MC (mobile nodes)
• Fast moving
• Point-to-point transmission
• IEEE802.11

Link IEEE802.11
MR
AP
MC
channel
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Network model
Link IEEE 802.11
S4
MCN

• - AP bandwidth is
• contended
• among transmitting
• nodes, i.e. Servers
• S1, S2, .. SN and
• receiving nodes, i.e.
• mobile clients MC1,
• MC2 ...MCN
• Servers S1, S2, .. SN
• models traffic from
• distribution system,
• each node sends
• one IP flow

AP
Channel N
S3
MC2
Channel 2
S2
Channel 1
MC1
S1
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Link model
Errors in different Channels statistically
independent
Rec. Node 1
Trans. node

• Bandwidth allocation

C1,, BER1
Brec-1
Boff-1
Channel 1
Rec. Node 2
C2,, BER2
Boff-2
Brec-2
Channel 2
Rec. Node N

• Varibility due to
• channel impairments
• MAC IEEE_802.11

CN,, BERN
Boff-N
Brec-N
Channel N
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Channel model
Transmitting node
Receiving node
Boff
Btrans
Brec
Gilbert channel model
Traffic control portion
Bqueue-loss
Bchannel-loss
sink
sink
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Contents
APPROACH FOR QOS PROVISION traffic control
algorithm design

• Models and basic assumptions
• Approach for QoS provision channel state
  dependent scheduling
• Statistics

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Design of traffic control
Mean link Capacity over time
Flow Classification
C(t)
Regulation
Link monitoring
Scheduling
S(t)
Instantaneous channel state vector
MAC IEEE802.11 (DCF) with no QoS
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Other design options

• Assessment for channel estimation
• SNR/SIR, Monitoring ACK reception, RTS/CTS frame
  exchange, BER/BLER measured at destination,
  Ad-hoc probing frames,
• Regulation strategies
• Algorithms Dual leaky buckets, markers,
  droppers,
• Strategies never drop, drop after deadline,
  deadline only for real-time traffic,
• Scheduling strategies
• Algorithms Round robin, priority queuing,
  weighted fair schedulers, deadline-based
  schedulers
• SELECTION CRITERIAS
• Computational cost
• Optimize metrics delay, congestion loss, channel
  loss

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Contents
STATISTICS

• Models and basic assumptions
• Approach for QoS provision channel state
  dependent scheduling
• Statistics

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Scenario 1 no contention
voce
FTP
video
video
HTTP
Ethernet P2P
voce
Link IEEE 802.11
FTP

• HTTP MSS2048 byte, AW 10MSS
• FTP MSS2048 byte, AW 10MSS
• Video 500 Mbps, Packetlength 2048 byte
• Voce 64 kbps, Packetlength 262 byte
• Channel capacity 2 Mbps
• BER 10

HTTP
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Scenario 2 with contention
voce
FTP
video
video
HTTP
voce
FTP

• HTTP MSS2048 byte, AW 10MSS
• FTP MSS2048 byte, AW 10MSS
• Video 250 Mbps, Packetlength 2048 byte
• Voce 32 kbps, Packetlength 262 byte
• Channel capacity 2 Mbps
• BER 10

HTTP
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Scenario 1 and Scenario 2 delays
Scenario 2
Scenario 1
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Scenario 1 and Scenario 2 congestion loss
Scenario 2
Scenario 1
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Scenario 1 and Scenario 2 channel loss
Scenario 2
Scenario 1
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Contents
APPENDIX OMNET SIMULATION MODELS

• Models and basic assumptions
• Approach for QoS provision channel state
  dependent scheduling
• Statistics

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Omnet models 1
AP model 1
EDFPF model 1
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Omnet models 2
EDFPF model 2