doc.: IEEE /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: Authors:

doc.: IEEE /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 /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 floor CCA 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 /0523r0 Submission How to enable reuse Noise floor CCA 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 CCI CCA STA Simultaneous transmission STA Simultaneous transmission April 2014 Imad Jamil (Orange)Slide 4

doc.: IEEE /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 /0523r0 Submission BSS Cluster3 Simulation scenario April 2014 Imad Jamil (Orange)Slide 6

doc.: IEEE /0523r0 Submission Tx :15 dBm [21 m] Close to scenario 3 - First tier only (7 BSSs), 8 STAs per BSS, Single channel for reuse 3 Simulation scenario April 2014 Imad Jamil (Orange)Slide 7 [7 m]

doc.: IEEE /0523r0 Submission Parameters PHY o IEEE n o Path Loss: ITU UMi ( log10(d)+ 21log10(2400/900MHz) ) o Band: 5 Ghz o Channel: 20 MHz o Tx power: 15 dBm Traffic o Full buffer UDP traffic o DL (AP->STA) o UL (STA->AP) Simple metric Aggregate throughput Fixed MCS or rate adaptation AARF Simulation scenario April 2014 Imad Jamil (Orange)Slide 8

doc.: IEEE /0523r0 Submission Fixed MCS7 – DSC and TPC No DSC DSC No TPC TPC Different margin ( ) April 2014 Imad Jamil (Orange)Slide 9

doc.: IEEE /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 /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 /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 /0523r0 Submission Rate control – DSC– mix with legacy devices All DSC-capable STAsDSC-capable STAs + 7 legacy STAs No DSCDSCNo DSCDSC April 2014 Imad Jamil (Orange)Slide 13

doc.: IEEE /0523r0 Submission Rate control - TPC – mix with legacy devices All TPC-capable STAsTPC-capable STAs + 7 legacy STAs No TPCTPCNo TPCTPC April 2014 Imad Jamil (Orange)Slide 14

doc.: IEEE /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 /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