Affiliations: Research Institute of Electrical Communication,
Graduate School of Information Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan. Tel.: +81 22 217 5454; E-mail:
{mostafa,deba,norio}@shiratori.riec.tohoku.ac.jp | School of Medicine, Tohoku University, 2-1
Seiryoumachi, Aoba-ku, Sendai, 980-8575, Japan. Tel.: +81 22 717 8024; E-mail:
nakamura@med.tohoku.ac.jp
Abstract: In recent years, wireless technologies and application received
great attention. The Medium Access Control (MAC) protocol is the main element
that determines the efficiency in sharing the limited communication bandwidth
of the wireless channel in wireless local area networks (WLANs). IEEE 802.11
introduced the optional RTS/CTS handshaking mechanism to address the hidden
terminal problem as well as to reduces the chance of collision in case of
higher node density and traffic. RTS Threshold (RT) determines when RTS/CTS
mechanism should be used and proved to be an important parameter for
performance characteristics in data transmission. We first investigate to find
a meaningful threshold value according to the network situation and determine
the impact of using or disengaging the RTS/CTS optional mechanism and
dynamically adjust the RTS Threshold to maximize data transmission. The results
show a significant improvement over existing CSMA/CA and RTS/CTS schemes. Our
adaptive scheme performed even better when data rate increases. We verify our
proposed scheme both analytically and with extensive network simulation using
ns-2.
