IEEE 802.11, which is the main standard for WLAN products, can not provide QoS support by its MAC ( Media Access Control ) coordination function – DCF ( Distributed Coordination Function ) and PCF ( Point Coordination Function ). 目前无线局域网产品普遍采用传统的IEEE802.11标准,其MAC(媒质接入控制)层的协调功能DCF(分布式协调功能)和PCF(点协调功能)却不能提供QoS支持。
It introduces a new coordination function, called Hybrid Coordination Function ( HCF ). HCF contains two access mechanisms : the Enhanced Distributed Channel Access ( EDCA ) and Hybrid Coordination Function Controlled Channel Access ( HCCA ). 在这个新的协议中,它引入了混合协调功能(HCF),根据竞争介质的方式不同,混合协调功能包含了增强的分布式协调控制接入机制(EDCA)和混合协调点控制接入机制(HCCA)。
The basis of IEEE 802.11 wireless LAN Medium Access Control ( MAC ) is Distributed Coordination Function ( DCF ). IEEE802.11无线局域网的基本接入方式是分布式协调功能(DCF)。
As to contention access function, our research focused on the distributed coordination function ( DCF ) and enhanced distributed channel access ( EDCA ) of WLAN. 对竞争接入机制的研究主要集中于无线局域网的分布式协调方式(DCF)和增强型分布式协调方式(EDCA)。