Course Outline

Section 1: 802.11 Operational Overview

In this section, we will review the basic operation of an 802.11 wireless network, including network architecture, MAC, and physical layers. You’ll learn to use a network analyzer to verify 802.11 MAC layer functionality.

A. Wireless LAN Client Devices

B. Wireless Access Points

1. Root Mode
2. Repeater Mode
3. Bridge Mode

C. Service Set Identifier (SSID)

D. 802.11 MAC Layer

1. Management Frames
2. Control Frames
3. Data Frames

E. 802.11 Physical Layer

Section 2: Power over Ethernet (PoE)

In this section you will learn to test and troubleshoot IEEE 802.3af Power over Ethernet solutions, including power injectors, and Active Ethernet switches.

A. IEEE 802.3af Overview

B. DC Voltage Injectors

1. Passive
2. Fault-Protected

C. Voltage & Pinout Standards

Section 3: Design Considerations

In this section you will learn to use a variety of tools and methods to evaluate your wireless network design, including coverage and capacity modeling, as well as roaming and throughput requirements. You will analyze antenna options, and transmission power settings, in order to achieve the desired coverage.

A. Comprehensive Site Survey

1. Facility Analysis
2. Existing Network Infrastructure (wired and wireless)

B. Site Survey Tools

1. Windows Tools
2. Linux Tools
3. Commercial Tools

C. RF Survey

1. Spectrum Analyzer
2. - Intentional Interference
3. Unintentional Interference

D. Capacity Planning

E. AP Placement

1. Obstacle-Induced Signal Loss

F. Antenna Selection & Orientation

Section 4: RF Related Problems

In this section you will focus on tuning and troubleshooting issues which are specific and unique to RF-based systems. You’ll test the impact on performance of various forms of RF interference. You’ll learn how antenna diversity counters multipath fade.

A. RF Propagation Modeling & Measuring

1. Received Signal Strength Indication (RSSI)
2. Noise Level
3. Signal-to-Noise Ratio (SNR)

B. Repeater Mode

C. Channel Reuse

1. Co-Channel Interference
2. Adjacent Channel Interference
3. Bluetooth Interference

D. Multipath Fade

1. Antenna Diversity
   
   

Section 5: AP Configuration

In this section you will learn to configure your WiFi Access Point to best meet your coverage and performance requirements. You will explore the impact each configurable parameter has on performance, and when and where it makes sense to deviate from the default settings.

A. Beacon Interval

B. Near/Far

1. RTS/CTS

C. Hidden Node

1. RTS/CTS

D. Fragmentation Threshold

E. Transmit Signal Strength

F. Antenna Diversity

Section 6: Optimizing Performance

In this section you will learn to establish performance baselines. You will explore options for enhancing range and throughput, and also prioritizing real-time applications, such as voice over IP. You will configure multiple VLANs (Virtual Local Area Networks) per AP, with a separate SSID (Service Set Identifier) for each VLAN.

A. Performance Testing & Analysis

B. VLAN Tagging

C. RF Amplification

D. Roaming

Section 7: Bridge Mode

In this section, you will focus on using 802.11b over longer distances to bridge between locations. You’ll learn to convert milliwatts to decibels, calculate loss and gain from cables, connectors, and antennas, as well as free space loss. We will also discuss the Fresnel Zone, and various forms of environmental fade.

A. Power Budget

1. Free Space Loss
2. Fresnel Zone

B. dB Math

C. Environmental Fade

15 HANDS-ON LABS

You must bring your laptop to participate in the labs.

• Lab 1: Initial Setup and Configuration
• Lab 2: Packet Capture & Analysis - Capture 802.11 management, control, and data frames to verify authentication, association, and data transfer.
• Lab 3: IEEE 802.3af Power over Ethernet Testing - Test an 802.3af compliant DC power injector.
• Lab 4: Pre-Installation Site Survey - Perform a pre-installation site survey using both Linux and Windows-based tools. Discover and document existing 802.11 devices and networks.
• Lab 5: Spectrum Analysis Site Survey - Use a spectrum analyzer to detect sources of interference.
• Lab 6: AP Placement Site Survey - Use site survey tools to map areas of coverage and obstacle-induced signal loss.
• Lab 7: Directional Antennas -
• Use semi-directional and highly-directional antennas to shape coverage area.
• Lab 8: Baseline Performance Testing -
• Establish throughput performance baselines for 802.11b, 802.11g, and 802.11a
• Lab 9: Performance-Related Statistics Analysis - Explore and analyze the access point performance statistics.
• Lab 10: Co-Channel & Adjacent Channel Interference - Test the performance impact of both co-channel, and adjacent-channel interference.
• Lab 11: Bluetooth Interference - Test the performance impact of Bluetooth on 802.11a/b/g.
  
• Lab 12: Mixed-Mode Performance Testing - Measure the differences between 802.11g exclusive-mode versus mixed-mode.
  
• Lab 13: Performance Tuning & Troubleshooting - Explore all performance-related configurable parameters, and test a range of settings for each.
  
• Lab 14: VLAN Tagging - Configure per-SSID VLAN tagging.
  
• Lab 15: Power Budget Calculation - Convert milliwatts to dBm, and calculate cable & connector loss, antenna gain, and free space loss, for a multi-mile bridged connection.
  
  

Equipment used in this course: Cisco Aironet • Linksys 802.11b/g Wireless Access Point • Buffalo AirStation 802.11b/g Wireless Access Point • Proxim Orinoco 802.11a Wireless Access Point • ZoomAir 802.11b PC card NIC • Orinoco Classic Gold 802.11b PC card NIC • Proxim Harmony 802.11a/b PC card NIC • Buffalo 802.11g PC card NIC • Orinoco WaveLAN Silver 802.11b PC card NIC • Netgear 802.11b PC card NIC • Proxim RangeLAN 802.11 FHSS PC card NIC • Symbol 2.4 GHz Spectrum Analyzer• Cantenna• Ekahau(tm)