Next Generation of Bluetooth and Wi-Fi

2Functional Overview of Wi-Fi

Wi-Fi-certified products in the commercial market, by general concept, utilize the physical layer and MAC layer protocols defined in the IEEE 802.11 standard. Note that Wi-Fi does not exactly equal IEEE 802.11, but instead is a commercial product name, or a certification, that is created through adopting multiple technologies specified in the 802.11 standard. Thus, it can be summarized that IEEE 802.11 is the standard that defines the procedures and algorithms, more specifically the protocols, that allows devices to use the specified wireless frequency for emission and reception of data (which we can generally refer as a form of communication) and use the set of communication to form a WLAN, whereas Wi-Fi, certification given by the Wi-Fi alliance, is a product which provides interoperability between all other Wi-Fi-certified devices based on IEEE 802.11. Therefore, not all devices based on IEEE 802.11 are Wi-Fi or must be Wi-Fi certified. However, Wi-Fi-certified products are based on subsets of technologies in the IEEE 802.11 standard. Therefore, when explaining the function details of Wi-Fi in this book, the majority of the explanations will be about the subsets of technologies within the IEEE 802.11 standard.

This chapter will introduce the basic functions of Wi-Fi’s physical layer and the medium access control layer. Note that the information in this chapter mostly concerns the fundamental functions and architecture of the legacy Wi-Fi or ...