CWNA: Certified Wireless Network Administrator Official Study Guide

1. Radio Frequency (RF) Technologies
RF Fundamentals
RF Mathematics
RF Signal and Antenna Concepts
RF Antenna Accessories
2. IEEE 802.11 Regulations and Standards
Spread Spectrum Technologies
IEEE 802.11-2007 Standard
IEEE 802.11 Industry Organizations and Their Roles
3. IEEE 802.11 Protocol and Devices
IEEE 802.11 Protocol Architecture
IEEE 802.11 MAC and PHY Layer Technologies
WLAN Infrastructure and Client Devices
4. IEEE 802.11 Network Implementation
IEEE 802.11 Network Design, Implementation, and Management
IEEE 802.11 Network Troubleshooting
Power over Ethernet (P0E)
WLAN Architectures
5. IEEE 802.11 Network Security
IEEE 802.11 Network Security Architecture
IEEE 802.11 Network Security Analysis, Performance Analysis, and Troubleshooting
IEEE 802.11 Network Security Policy Basics
6. IEEE 802.11 RF Site Surveying
IEEE 802.11 Network Site Survey Fundamentals
IEEE 802.11 Network Site Survey Systems and Devices

5GHz vs. 2.4GHz Spectrum

Today there are two primary 802.11 standards used in the enterprise:
  • 802.11b/g operating in the 2.4GHz radio spectrum
  • 802.11a operating in the 5GHz radio spectrum
Consider the following when deciding on deploying 5GHz, 2.4GHz, or both:

5GHz2.4GHzAdvantage Defined
Bandwidth54/300Mbps54/300MbpsBoth choices support up to 54Mbps of bandwidth today and up to 300Mbps when the new 802.11n standard is deployed.
Channels243Restrictions in the 2.4GHz band limit the number of simultaneously channels to 3, while the 5GHz band offers up to 24.
Capacity3.45Gbps 450MbpsThe 24 channels available with 5GHz far exceed the capacity of 2.4GHz.
802.11a = 1.24Gbps / 802.11n = 3.45Gbps (5GHz)
802.11g = 162Mbps / 802.11n = 450Mbps (2.4GHz)
InterferenceLowHighWi-Fi in 2.4GHz competes with microwaves, Bluetooth, wireless phones, etc. resulting in a very noisy environment. The 5GHz band is considerably cleaner.
Channel PlanningFlexibleRestrictedWith 8 times the number of channels to chose from in the 5GHz band, planning is far simpler than the 2.4GHz band.
Triple Play SupportOptimalLimitedOnly 5GHz supports the bandwidth, capacity, and throughput required for enterprise quality voice, video, and data applications.
802.11nOptimalLimitedAlthough 802.11n supports both bands, the available channels, bandwidth, and client capacity makes the 5GHz band the obvious choice.
RangeGoodBetterEven though the 2.4GHz band has greater range than 5GHz, proper deployment using directional antennas can eliminate any issue.
By integrating 4, 8, or 16 802.11a/b/g radios and a high-gain directional antenna system with an onboard Gigabyte Switch, Wi-Fi Controller, Wi-Fi Firewall, and dedicated Wi-Fi Threat Sensor into a single device.