1. A New Metric for Evaluating the Throughput of HEW
Month Year
doc.: IEEE /xxxxr0
March 2014
A New Metric for Evaluating the Throughput of HEW
Date:
Authors:
Yunzhou Li, Tsinghua Univ.
Yunzhou, Tsinghua

2. Mar 2013
Background
Yunzhou Li, Tsinghua Univ.

3. Inefficiencies of Current WLAN
September 2012
doc.: IEEE /xxxxr0
March 2014
Inefficiencies of Current WLAN
Assume all APs are blind, in other words, they know know nothing about STAs.
Strategies
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

4. Inefficiencies of Current WLAN
September 2012
doc.: IEEE /xxxxr0
March 2014
Inefficiencies of Current WLAN
Notorious Exposed Node Problem:
Strategies
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

5. Inefficiencies of Current WLAN
September 2012
doc.: IEEE /xxxxr0
March 2014
Inefficiencies of Current WLAN
MAC and PHY layers are blind to their upper layers.
Traffic Properties
Strategies
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

6. September 2013
HEW with Intelligence
Yunzhou Li, Tsinghua Univ.

7. Acquire Prior Knowledge of STAs
September 2012
doc.: IEEE /xxxxr0
March 2014
Acquire Prior Knowledge of STAs
STAs
1) often stay at some places for a long time;
2) try to access or once connected to different APs
Therefore:
APs can
learn some prior knowledge of STAs based on the previous measurements;
adjust transmission modes to reach High Efficiency.
Strategies
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

8. September 2012
doc.: IEEE /xxxxr0
March 2014
Key Idea
Besides the traditional per-BSS and per-STA throughput, We suggests a new metric named as throughput with learned knowledge.
large-scale channel state information (CSI);
positions of STAs relative to the APs;
statistical properties of different kinds of traffics (e.g., video and voice);
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

9. Large-scale CSI for Improving Efficiency
September 2012
doc.: IEEE /xxxxr0
March 2014
Large-scale CSI for Improving Efficiency
Full CSI are hard to be acquired by APs, because
Channel is varying;
Every AP can only estimate the CSIs of its own STAs.
But, large-scale fading coefficients (i.e. large-scale CSI) can be obtained easily, because
they could keep constant for a long time;
STAs could have connected to different APs previously.
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

10. Large-scale CSI for Improving Efficiency
September 2012
doc.: IEEE /xxxxr0
March 2014
Large-scale CSI for Improving Efficiency
. Power Allocation among APs based on Large-scale CSI
Virtual MIMO in Multi-Cell Distributed Antenna Systems: Coordinated Transmissions with Large-Scale CSIT, JSAC 2013
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

11. Spatial Information for Improving Efficiency
September 2012
doc.: IEEE /xxxxr0
March 2014
Spatial Information for Improving Efficiency
Solving the Exposed Node Problem:
Make AP1 and AP2 know the Spatial Positions of STA1 and STA2
Strategies
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

12. Traffic Properties for Improving Efficiency
September 2012
doc.: IEEE /xxxxr0
March 2014
Traffic Properties for Improving Efficiency
Cross-layer Design.
Traffic Properties (time sensitive or not, Error sensitive or not, etc.)
Strategies
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

13. Traffic Properties for Improving Efficiency
September 2012
doc.: IEEE /xxxxr0
March 2014
Traffic Properties for Improving Efficiency
Similar as WiFox[1], StreamBoost[2], WLAN could be optimized based on the statistical characteristics of data-traffics.
[1]
[2]
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

14. September 2012
doc.: IEEE /xxxxr0
March 2014
Proposal
Evaluate the throughput of HEW under some important prior knowledge of STAs;
IEEE 1588 & synchronization
Coordinated frequency band
Coordinated power and frequency band
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.

15. September 2012
doc.: IEEE /xxxxr0
March 2014
Summary
Some prior knowledge of STAs could be useful for improving the efficiency of HEW. They can be learnt by APs when APs are communicating with STAs.
Throughput of HEW should be re-evaluated under the prior knowledge of STAs.
IEEE 1588 & synchronization
Coordinated frequency band
Coordinated power and frequency band
Yunzhou Li, Tsinghua Univ.
Yasuhiko Inoue (NTT), et. al.