1. MAC Throughput Enhancement by Dynamic dot11RTSThreshold
JULY 2003
MAC Throughput Enhancement by Dynamic dot11RTSThreshold
Woo-Yong Choi and Sok-Kyu Lee
Electronics and Telecommunications Research Institute
Woo-Yong Choi, ETRI

2. Contents Introduction Effects of RTS-CTS Frame Exchange
JULY 2003
Contents
Introduction
Effects of RTS-CTS Frame Exchange
Dynamic dot11RTSThreshold
Throughput Analysis
Conclusions
Woo-Yong Choi, ETRI

3. JULY 2003
Introduction
MAC protocol should be further enhanced to meet the target of HT SG
Parameter optimization can be one of methods to enhance the throughput
dot11RTSThreshold is one of parameters to have the great effect on MAC throughput
Objective
To enhance MAC throughput by the dynamic selection of dot11RTSThreshold value according to the load imposed on (Q)BSS
Woo-Yong Choi, ETRI

4. Effects of RTS-CTS Frame Exchange
JULY 2003
Effects of RTS-CTS Frame Exchange
Advantage
Solve the hidden node problem
Shortening the collision period
Great method in overload period in (Q)BSS
Disadvantage
Overhead transmission
Bad method in underload period in (Q)BSS
Woo-Yong Choi, ETRI

5. Dynamic dot11RTSThreshold
JULY 2003
Dynamic dot11RTSThreshold
dot11RTSThreslod can be selected independently by each (Q)STA
But, dot11RTSThreshold can have the effect on the throughput of the (Q)BSS
Worst case scenario: each (Q)STA use dot11RTSThreshold value of 0 in underload period or each (Q)STA use dot11RTSThreshold value of maximum in overload period
Woo-Yong Choi, ETRI

6. Dynamic dot11RTSThreshold
JULY 2003
Dynamic dot11RTSThreshold
We propose that the value of dot11RTSThreshold used by (Q)STAs in the (Q)BSS be broadcast via beacon frame
Considering the traffic load imposed on the (Q)BSS, dot11RTSThreshold value should be dynamically selected to have a good throughput performance
Woo-Yong Choi, ETRI

7. JULY 2003
Simulation Condition
n greedy STAs attempt to transmit data frames continuously using DCF protocol
The size of payloads in data frames is variable: uniform distribution in [0, 2312 bytes]
F: Distribution function of the payload size
No hidden STAs
Woo-Yong Choi, ETRI

8. JULY 2003
Throughput Analysis
Woo-Yong Choi, ETRI

9. JULY 2003
Throughput Analysis
Woo-Yong Choi, ETRI

10. Performance Improvements
JULY 2003
Performance Improvements
Average 17 % throughput improvement in IEEE a
Average 14 % throughput improvement in IEEE b
Throughput improvements become greater as the number of STAs increases
Woo-Yong Choi, ETRI

11. JULY 2003
Conclusions
Dynamic dot11RTSThreshold can improve MAC throughput performance
We propose that the value of dot11RTSThreshold used by (Q)STAs in the (Q)BSS be broadcast via beacon frame
Woo-Yong Choi, ETRI