1. Submission doc.: IEEE 11-10/1511r0 Company Confidential November 2011 Chittabrata Ghosh, NokiaSlide 1 Fairness of DCF in 802.11ah Date: 2011-11-07 Authors:

2. Submission doc.: IEEE 11-10/1511r0 Company Confidential Abstract Study the fairness of DCF for 802.11ah depending on the traffic load with different DCF parameters Slide 2Chittabrata Ghosh, Nokia November 2011

3. Submission doc.: IEEE 11-10/1511r0 Company Confidential Simulation Scenarios Num of AP: 1 Num of Stations: 1000 Topology: Slide 3Chittabrata Ghosh, Nokia November 2011

4. Submission doc.: IEEE 11-10/1511r0 Company Confidential Simulation Parameters Slide 4Chittabrata Ghosh, Nokia November 2011 Channel Bandwidth2MHz and 1000 nodes Data Rate100bps[1] /500bps/1kbps TX Power20dBm Antenna Gains3dB Max Communication Range1012 Meters (-88dBm) Max Interference Range1293 Meters (-92dBm) Packet Size250Bytes DIFS256µs SIFS160µs Slot Time48µs CWmin15/63/127/255/511 CWmax1023/1023/1023/2047/4095 Simulation time160s MCSBPSK ½

5. Submission doc.: IEEE 11-10/1511r0 Company Confidential Simulation Parameters 2 Pathloss model Outdoor Macro [2]: PL(d) =8+37.6log10(d) Station to Station model [3]: PL(d)=16.90 + 42.4*log10(d) Traffic Model Simulation Time = 160 Seconds TX time for each packet is randomly selected in the 160 seconds Slide 5Zhong-Yi Jin, Nokia November 2011 160 seconds

6. Submission doc.: IEEE 11-10/1511r0 Company Confidential Fairness: throughput CDF (CWmin 15) Slide 6Chittabrata Ghosh, Nokia November 2011 RTS/CTSWithout RTS/CTS

7. Submission doc.: IEEE 11-10/1511r0 Company Confidential Fairness: STA with throughput zero (CWmin 15) Slide 7Chittabrata Ghosh, Nokia November 2011

8. Submission doc.: IEEE 11-10/1511r0 Company Confidential Effect of increasing load on througput with link adaptation (CWmin 15) Slide 8Chittabrata Ghosh, Nokia November 2011

9. Submission doc.: IEEE 11-10/1511r0 Company Confidential STA with zero throughput for varying CW Slide 9Chittabrata Ghosh, Nokia November 2011 Without RTS/CTSWith RTS/CTS

10. Submission doc.: IEEE 11-10/1511r0 Company Confidential Conclusions DCF is unfair and inefficient in terms of energy and throughput under heavy/bursty traffics Varying CW sizes does not solve the problem Slide 10Chittabrata Ghosh, Nokia November 2011

11. Submission doc.: IEEE 11-10/1511r0 Company Confidential References [1] 11-11-1229-r0 TGah 11ah M2M channel access performance [2] TGah channel model – proposed text, IEEE802.11- 11/0968r1 [3] STA-STA Pathloss Model, IEEE802.11-11/1263r4 Slide 11Chittabrata Ghosh, Nokia November 2011