中文摘要：

为了解决现有无线局域网中媒体访问控制层协议多播时效率较低的问题,在扩展隐式媒体访问控制层确认帧协议基础上,提出了一种无线局域网下的可靠多播差错控制协议——确定时间的随机扩展隐式媒体访问控制层确认帧协议.该协议通过引入领导者（Leader）和减少纠错时多播允许发送帧数量,降低了发送数据帧时所需占用信道的时间,提高了用于数据传输的实际时间开销占整个多播过程的时间比例.仿真实验结果表明,新协议有效地提高了多播的总体性能,显著增加了网络的实际吞吐量.

英文摘要：

In order to solve the problem that the existing medium access control（MAC） layer protocols in wireless local area networks（WLAN） are less efficient,a fixed time and random extended implicit MAC Acknowledgment protocol is proposed on basis of extended implicit MAC acknowledgment（EIA）.Since the proposed protocol brings in the leader and reduces the number of the multicast clear to send frames,the average channel holding time of transmitting data is reduced and the ratio of the real data transmission cost in entire multicast stage is increased.Simulations show that the proposed fixed time random extended implicit MAC acknwledgment protocol effectively improves the overall performance of multicast in WLAN and effectively increases the network goodput compared with EIA.