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

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

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

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

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

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

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

JULY 2003 Throughput Analysis Woo-Yong Choi, ETRI

JULY 2003 Throughput Analysis Woo-Yong Choi, ETRI

Performance Improvements JULY 2003 Performance Improvements Average 17 % throughput improvement in IEEE 802.11a Average 14 % throughput improvement in IEEE 802.11b Throughput improvements become greater as the number of STAs increases Woo-Yong Choi, ETRI

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