Introduction

The primary advantage of wireless local area networks (WLANs) is their ability to communicate to the wired network or to other WLAN devices. Integrating both wired network and wireless LAN technologies into a single device allows you to have the best of both worlds. In addition to the radio technologies enabling WLANs, other technologies are employed to provide security, efficiency, and stability of the WLAN. Because WLAN radio devices use various aspects of radio technology, we first review radio frequency (RF) fundamentals. We define and explain the various RF apparatus as it pertains to the functionality of WLANs. This chapter provides an overview of WLANs to provide a knowledge base for more detailed wireless networking topics. We provide information concerning the underlying concepts and technologies used in wireless systems in order to enhance your ability to design, implement, and troubleshoot the various processes of a wireless system. You will be given the practical information necessary to understand the functionality of any WLAN radio device to include Cisco Aironet products. Because this subject matter represents such a broad range of topics and technologies, discussing them all in the course of one chapter is difficult at best. Instead, we give focus to the fundamentals and standards as they directly relate to WLANs. Next, we discuss current wireless technologies and the advantages and disadvantages of various wireless technology implementations, with greater attention given to the technology used by Cisco Aironet devices. Finally, we turn our attention to standards with respect to wireless...