A Same-Priority Collision-Avoidance Algorithm Using RTS/CTS Frame in IEEE 802.11e EDCA under Network Congested Condition

The Enhanced Distributed Channel Access (EDCA) function of IEEE 802.11e standard defines contention window (CW) for different Access Category (AC) limits to support Quality-of-Service (QoS). However, it have been remained the problem that the collision probability of transmission is increasing in congested network. Several different solutions have been proposed but the collision occurs among same priority queue within the same station to compete the channel access. This paper presents an APCA (Advanced Priority Collision Avoidance) algorithm for EDCA that increases the throughput in saturated situation. The proposed algorithm use reserved field’s bits of FC(Frame Control) using IEEE 802.11e standard’s RTS/CTS (Request to Send / Clear to Send) mechanism to avoid data collision. The simulation results show that the proposed algorithm improves the performance of EDCA in packet loss. Using Jain’s fairness index formula, we also prove that the proposed APCA algorithm achieves the better fairness than EDCA method under network congested condition. 논문 14-39C-05-04 The Journal of Korea Information and Communications Society '14-05 Vol.39C No.05 http://dx.doi.org/10.7840/kics.2014.39C.5.425 425 First Author:Hanyang University, Department of Electronic and Computer Engineering, phylio@hanyang.ac.kr, 학생회원 ° Corresponding Author:Hanyang University, Department of Computer Engineering, bhrhee@hanyang.ac.kr, 정회원 논문번호:KICS2014-01-010 Received January 20, 2014; Revised April 30, 2014; Accepted May 15, 2014 The Journal of Korea Information and Communications Society '14-05 Vol.39C No.05