WLAN Technology Basics
Rihai Wu, Xun Yang, Xia Zhou, Yibo Wang · 2021
This chapter begins with the basic concepts of wireless communication and key wireless local area network technologies before moving on to the evolution and version comparison of Institute of Electrical and Electronics Engineers 802.11 standards, and finishes with a discussion of the next-generation 802.11ax in terms of key technologies at the physical and Media Access Control (MAC) layers in addition to basic principles. In the case of bound channels, 802.11 standards stipulate that one will function as the primary channel and the other as the secondary channel. The carrier sense (CS) process involves monitoring a channel to determine whether the channel is busy or idle. In line with wireless channel characteristics, 802.11 standards proposed physical and virtual CS modes that run concurrently. To avoid collisions, 802.11 standards require that all STAs wait before transmitting frames at the MAC layer.