CAJ | 학술논문

为了提升无线网络的整体性能，通过IEEE 802.11 MAC(媒体访问控制)层DCF(分布式协调功能)在基本工作模式下所使用的二进制退避算法和CW(竞争窗口)的大小对网络整体性能的影响进行了分析。采用了增大初始 CW、取消信道从忙碌变为空闲后继续退避需要等待的DIFS (分布式帧间间隔)和设置一个中间值作为阀值使得节点发送失败或成功后采用不同的退避算法进行退避这3种措施来优化DCF方式下的退避机制。经 OPNET仿真验证，改进算法能够有效地降低网络接入时延并能提高网络吞吐量。
위료제승무선망락적정체성능，통과IEEE 802.11 MAC(매체방문공제)층DCF(분포식협조공능)재기본공작모식하소사용적이진제퇴피산법화CW(경쟁창구)적대소대망락정체성능적영향진행료분석。채용료증대초시 CW、취소신도종망록변위공한후계속퇴피수요등대적DIFS (분포식정간간격)화설치일개중간치작위벌치사득절점발송실패혹성공후채용불동적퇴피산법진행퇴피저3충조시래우화DCF방식하적퇴피궤제。경 OPNET방진험증，개진산법능구유효지강저망락접입시연병능제고망락탄토량。
In order to enhance the overall performances of wireless networks,this paper analyzes the influences of the binary back-off algorithm and the size of Contention Window (CW)used for the Distributed Coordination Function (DCF)of the Media Access Control (MAC)layer of IEEE802.11 wireless networks in the fundamental working mode.It then optimizes the back-off mechanism by increasing the initial CW,cancellthe Distributed InterFrame Space (DIFS)that busy channels need to wait for when they become idle but still have to be back-off and set up an intermediate value as a threshold so that different back-off algorithms are adopted when node transmission is a success or a failure.OPNET simulation results show that the im-proved algorithm can effectively reduce network access delay and improve the system throughput.