Title :
A new constrained-send mechanism to enhance the performance of IEEE 802.11 DCF
Author :
Wang, Guo ; Zhong, Xiaofeng ; Mei, Shunliang ; Wang, Jing
Author_Institution :
Dept. of Electron. Eng., Tsinghua Univ., Beijing, China
Abstract :
In this paper, we proposed a modified access mechanism named Constrained-send DCF (CDCF) to improve the performance of IEEE 802.11 DCF protocol. We find that, in DCF, the transmission probability is higher than the reasonable value when the node number is greater than 4 under basic access scheme or than 17 under RTS/CTS scheme, and it results in serious collision. To constrain stations´ transmission, we introduced a constrained-send probability at the end of each backoff procedure. We analyzed the performance of this mechanism based on a 2-Dimension Markov analytical model, after that we derived the optimum constrained-send probability. Numerical results show that the CDCF mechanism has much better performance than DCF with respect to both throughput and average packet delay. And under RTS/CTS scheme, although CDCF slightly improve the throughput performance (due to the natural good throughput performance of RTS/CTS-scheme DCF), it leads to a much better average packet delay performance compared to DCF. The CDCF keeps all the features of the IEEE 802.11 DCF protocol and is quite easy to implement.
Keywords :
Markov processes; probability; protocols; wireless LAN; 2-dimension Markov analytical model; CDCF mechanism; IEEE 802.11 DCF protocol; RTS-CTS scheme; average-packet delay performance; constrain station transmission; constrained-send DCF; modified-access mechanism; node number; optimum constrained-send probability; transmission probability; Delay; Equations; IEEE 802.11 Standards; Markov processes; Mathematical model; Protocols; Throughput; DCF; average packet delay; constrained-send probability; throughput;
Conference_Titel :
Communications and Networking in China (CHINACOM), 2011 6th International ICST Conference on
Conference_Location :
Harbin
Print_ISBN :
978-1-4577-0100-9
DOI :
10.1109/ChinaCom.2011.6158196