Radio Frequency Fundamentals

This part of the CVD discusses Radio Frequency (RF) fundamentals that are necessary to understand before deploying a Wireless LAN network that is location and CMX ready. The chapter explains various RF concepts like spectrum bands, power level, signal strength, RSSI, etc. and provides a simple example using these concepts to illustrate how RF impacts a client and Access Point perceived signal strength level. These components include Cisco wireless LAN controllers (WLCs), Cisco Prime Infrastructure (PI), and the Cisco Mobility Services Engine (MSE). In addition, the configuration of CMX services, specifically CMX Analytics and CMX Visitor Connect, are discussed. A good WLAN deployment either in the 2.4 GHz spectrum or the 5 GHz spectrum is contingent on Radio Frequency Planning. As we noted, because WLAN technology operates in the unlicensed bands provided by the FCC, many other wireless technologies such as Bluetooth also use the same spectrum. It is important for WLAN deployments to consider RF characteristics, regulatory domains, maximum transmittable power by APs, and RF interference from other bands. This chapter explains the basic terminologies used in radio frequencies and how they tie into the WLAN deployment. General guidelines on designing a WLAN with RF in mind are covered in Chapter 14, “Pre-Deployment Radio Frequency Site Survey.”