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Introduction
Chapter 1 RF Signals and Modulation 3 "Do I Know This Already?" Quiz 3 Foundation Topics 7 Comparing Wired and Wireless Networks 7 Understanding Basic Wireless Theory 7 Understanding Frequency 9 Understanding Phase 14 Measuring Wavelength 14 Understanding RF Power and dB 15 Important dB Laws to Remember 17 Comparing Power Against a Reference: dBm 19 Measuring Power Changes Along the Signal Path 20 Understanding Power Levels at the Receiver 23 Carrying Data Over an RF Signal 24 FHSS 26 DSSS 27 1-Mbps Data Rate 28 2-Mbps Data Rate 28
5.5-Mbps Data Rate 29 11-Mbps Data Rate 30 OFDM 30 Modulation Summary 32 Exam Preparation Tasks 34 Review All Key Topics 34 Key Terms 34
Chapter 2 RF Standards 37 "Do I Know This Already?" Quiz 37 Foundation Topics 41 Regulatory Bodies 41 ITU-R 41 FCC 42 ETSI 44 Other Regulatory Bodies 45 IEEE Standards Body 45
802.11 Channel Use 47 Channels in the
2.4-GHz ISM Band 47 Channels in the 5-GHz U-NII Bands 49 IEEE
802.11 Standards 50
802.11-1997 51
802.11b 51
802.11g 52
802.11a 53
802.11n 54 Channel Aggregation 55 Spatial Multiplexing 57 MAC Layer Efficiency 58 Transmit Beamforming 59 Maximal-Ratio Combining 60
802.11n Modulation and Coding Schemes 60
802.11ac 60 Robust Channel Aggregation 61 Dense Modulation 63 MAC Layer Efficiency 63 Explicit Transmit Beamforming 64 Scalable MIMO 64 Multi-user MIMO 64
802.11ac Implementation 65
802.11 in Other Frequency Bands 65 Wi-Fi Alliance 66 Exam Preparation Tasks 68 Review All Key Topics 68
802.11 Protocol Summary 68 Define Key Terms 69
Chapter 3 RF Signals in the Real World 71 "Do I Know This Already?" Quiz 71 Foundation Topics 74 Interference 74 Co-Channel Interference 74 Neighboring Channel Interference 75 Non-802.11 Interference 76 Free Space Path Loss 77 Mitigating the Effects of Free Space Path Loss 79 Effects of Physical Objects 80 Reflection 81 Absorption 82 Scattering 83 Refraction 83 Diffraction 84 Fresnel Zones 84 Exam Preparation Tasks 88 Review All Key Topics 88 Define Key Terms 88
Chapter 4 Understanding Antennas 91 "Do I Know This Already?" Quiz 91 Foundation Topics 94 Antenna Characteristics 94 Radiation Patterns 94 Gain 97 Beamwidth 97 Polarization 98 Antenna Types 99 Omnidirectional Antennas 99 Directional Antennas 103 Antenna Summary 107 Adding Antenna Accessories 107 Exam Preparation Tasks 109 Review All Key Topics 109 Define Key Terms 109
Chapter 5 Wireless LAN Topologies 111 "Do I Know This Already?" Quiz 111 Foundation Topics 114 Types of Wireless Networks 114 Wireless LAN Topologies 115 Basic Service Set 116 Distribution System 118 Extended Service Set 120 Independent Basic Service Set 122 Other Wireless Topologies 122 Repeater 122 Workgroup Bridge 123 Outdoor Bridge 124 Mesh Network 125 Exam Preparation Tasks 126 Review All Key Topics 126 Define Key Terms 126
Chapter 6 Understanding
802.11 Frame Types 129 "Do I Know This Already?" Quiz 129 Foundation Topics 132
802.11 Frame Format 132
802.11 Frame Addressing 134 Accessing the Wireless Medium 136 Carrier Sense 137 Collision Avoidance 137
802.11 Frame Types 140 Management Frames 140 Control Frames 141 Data Frames 142 Client Housekeeping 142 A Client Scans for APs 143 A Client Joins a BSS 144 A Client Leaves a BSS 145 A Client Moves Between BSSs 146 A Client Saves Power 147 Exam Preparation Tasks 151 Review All Key Topics 151 Define Key Terms 151
Chapter 7 Planning Coverage with Wireless APs 153 "Do I Know This Already?" Quiz 153 Foundation Topics 157 AP Cell Size 157 Tuning Cell Size with Transmit Power 157 Tuning Cell Size with Data Rates 159 Adding APs to an ESS 162 The Roaming Process 163 WLAN Channel Layout 165 Designing and Validating Coverage with Site Surveys 169 Applications and Their Requirements 169 Site Survey Types and Tools 171 Predictive or Planning Surveys 172