doc.: ieee 802.11-14/0523r0 submission april 2014 imad jamil (orange)slide 1 mac simulation results...
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doc.: IEEE 802.11-14/0523r0
Submission
April 2014
Imad Jamil (Orange)Slide 1
MAC simulation results for Dynamic sensitivity control (DSC - CCA adaptation)
and transmit power control (TPC)
Date: 2014-04-17
Name Company Address Phone email Imad Jamil Orange 4 rue du clos Courtel
35512 Cesson Sévigné France
Laurent Cariou Orange 4 rue du clos Courtel 35512 Cesson Sévigné France
+33 299124350 [email protected]
Thomas Derham Orange 9F Keio Shinjuku Oiwake Bldg. Shinjuku 3-1-13, Tokyo, Japan
+81 3 5312 8563
Jean-Pierre Le Rouzic Orange 4 rue du Clos Courtel 35512 Cesson Sevigne
France
+33 299124893 [email protected]
Authors:
doc.: IEEE 802.11-14/0523r0
Submission
Context
• In dense environments, CSMA-CA parameters (especially CCA physical carrier sensing) as defined in the standard are quite conservative.
– reducing reuse between neighboring cells
• Several presentations have takled this problem:– adaptation of this CCA (dynamic sensitivity control)
– adaptation of transmit power
• In this presentation, we run a set of simulations to confirm/infirm first insights regarding these schemes
– MAC system simulator with simple PHY abstraction
April 2014
Imad Jamil (Orange)Slide 2
doc.: IEEE 802.11-14/0523r0
Submission
co-channel interference (CCI) from neighboring cells
• In scenarios where the useful receive power is always sufficiently higher than interference, reuse between neighboring cells is possible
– but currently prevented by CCA threshold
Noise floorCCA
Min SINR to receive MCSx(sensitivity)
CCI
Useful Rx power
CCI
Simultaneous transmission
AP
STA
Interfering AP
Co-Channel interference (CCI)
STA
April 2014
Imad Jamil (Orange)Slide 3
doc.: IEEE 802.11-14/0523r0
Submission
How to enable reuse
Noise floorCCA
CCI
Min SINR to receive MCSx(sensitivity)
Useful Rx Power
CCI
1: Transmit power control
AP
STA
Interfering AP
Co-Channel interference (CCI)
AP
STA
Interfering AP
Co-Channel interference (CCI)
2: CCA control (DSC)
Noise floor
Min SINR to receive MCSx(sensitivity)
Useful Rx Power
CCICCA
STA
Simultaneous transmission
STA
Simultaneous transmission
April 2014
Imad Jamil (Orange)Slide 4
doc.: IEEE 802.11-14/0523r0
Submission
Simulate simple algorithms
• DSC (CCA control):– each STA adjust CCA to CCA = Useful Rx Power – Margin
• TP control:• each receiver requests transmitter to adjust TP so that it receives the Useful Rx Power at
Margin dB above classical CCA (-82dBm)
• In each case, the margin has a strong relationship with the min SINR experienced by STAs
– we are not discussing any protocol in here
AP
STA tune CCA level (and receiver sensitivity)
AP
STA
tune TP
April 2014
Imad Jamil (Orange)Slide 5
tune CCA level
doc.: IEEE 802.11-14/0523r0
Submission
BSSBSS
ClusterCluster33
Simulation scenario
April 2014
Imad Jamil (Orange)Slide 6
doc.: IEEE 802.11-14/0523r0
Submission
Tx :15 dBmTx :15 dBm
Tx : 15 dBmTx : 15 dBm
[21 m][21 m]
Close to scenario 3
- First tier only (7 BSSs), 8 STAs per BSS, Single channel for reuse 3
Simulation scenarioApril 2014
Imad Jamil (Orange)Slide 7
[7 m][7 m]
doc.: IEEE 802.11-14/0523r0
Submission
ParametersPHYoIEEE 802.11noPath Loss: ITU UMi (23.3+36.7log10(d)+ 21log10(2400/900MHz))oBand: 5 GhzoChannel: 20 MHzoTx power: 15 dBm
TrafficoFull buffer UDP trafficoDL (AP->STA)oUL (STA->AP)
Simple metricAggregate throughput
Fixed MCS or rate adaptation AARF
Simulation scenarioApril 2014
Imad Jamil (Orange)Slide 8
doc.: IEEE 802.11-14/0523r0
Submission
Fixed MCS7 – DSC and TPC
No DSC DSC No TPC TPC
Different margin (10-15-20-25-30-35-40-50)
April 2014
Imad Jamil (Orange)Slide 9
doc.: IEEE 802.11-14/0523r0
Submission
Rate control – DSC and TPC
Different set of MCSs for rate control:-all MCSs, MCS 2-7, MCS 3-7, MCS 4-7, MCS 5-7, MCS 6-7
No DSC DSC No TPC TPC
April 2014
Imad Jamil (Orange)Slide 10
doc.: IEEE 802.11-14/0523r0
Submission
First observations
• CCA and TPC are strongly increasing reuse and aggregate throughput– Margin optimization
• Weak rate control algorithms make aggregate throughput collapse
• The margin gives an indication on min SINR– if used for suppression of MCS usage below this min SINR
– it leads to strong improvement of rate control efficiency and to aggregate throughput gains
April 2014
Imad Jamil (Orange)Slide 11
doc.: IEEE 802.11-14/0523r0
Submission
Impact of legacy devices
• mix of legacy (not implementing DSC or TPC) and DSC/TPC-capable STAs (implementing DSC or TPC)
– 1 legacy STA per BSS
April 2014
Imad Jamil (Orange)Slide 12
doc.: IEEE 802.11-14/0523r0
Submission
Rate control – DSC– mix with legacy devices
All DSC-capable STAs DSC-capable STAs + 7 legacy STAs
No DSC DSC No DSC DSC
April 2014
Imad Jamil (Orange)Slide 13
doc.: IEEE 802.11-14/0523r0
Submission
Rate control - TPC – mix with legacy devices
All TPC-capable STAs TPC-capable STAs + 7 legacy STAs
No TPC TPC No TPC TPC
April 2014
Imad Jamil (Orange)Slide 14
doc.: IEEE 802.11-14/0523r0
Submission
First observations for mix with legacy
• As expected, the impact of legacy devices on aggregate throughput is way stronger with TPC than with DSC
– with TPC, those legacy are disabling any reuse possibility
– with TPC, those legacy are also disturbing the relationship between the margin and the min SINR and cancels MCS suppression benefits in rate control algorithms
April 2014
Imad Jamil (Orange)Slide 15
doc.: IEEE 802.11-14/0523r0
Submission
Conclusion/next steps
• Preliminary results with MAC system simulator are showing – very good per user throughput gains both for TPC and DSC– additional benefit of the « margin » for rate adaptation
improvement through desabling the use of low MCSs– strong impact of legacy devices on TPC reuse efficiency
• Next steps– simulator evolution (calibrated)– different scenarios– analysis of potential starvation of legacy devices in case of DSC– analysis of RTS/CTS impact
April 2014
Imad Jamil (Orange)Slide 16