中文摘要：

目前无线局域网（WLAN）中使用最广的是IEEE 802．11协议，该协议定义了两种信道访问机制：分布式协调功能（DCF）和点协调功能（PCF）。其中，DCF采用基于竞争的信道访问机制，因此，多个连有传感器的站点采集数据在信道中传输就会出现碰撞和时延不可控的问题；而PCF采用轮询的方式来提供一种非竞争的访问机制，很好地解决时延不可控制的问题。针对这种情况，提出采用集中控制协议完成PCF访问机制，协议中定义超帧结构并将超帧划分为多个时隙，以此实现无竞争的信道访问机制。实验结果表明：整个网络中传感器采集数据最大接入时延控制在90ms以内。

英文摘要：

For wireless local area network（WEAN） ,the most popular protocol is IEEE 802.11 ,which defines two different channel access mechanisms, i. e. distributed coordination function（DCF） and point coordination function （PCF）. Specifically, DCF works based on the mechanism of competition, which may lead to collision and uncontrollable delay for the acquisition data by station connected with sensors while transmitting in channel. Nevertheless,PCF works as a non-competitive access mechanism using round enquiry way, which can control the delay efficiently. Aiming at this case, utilize centralized control protocol to achieve PCF access mechanism, structure of superframe is defined in the protocol and each superframe is divided into a plurality of time slots, so as to realize non-competitive channel access mechanism. Experimental results show that the maximum access delay is controlled within 90ms.