1 Certified Wireless Network Professional :: CWNA-109 Student Guide for CWNA-109
2 Certified Wireless Network Professional :: CWNA-109 CWNA-109 Exam launched September 30, 2023 New courseware New study guide – in living color New practice exams
3 Certified Wireless Network Professional :: CWNA-109 CWNA-109 Knowledge Domains CWNA-109 CWNA-108
4 Certified Wireless Network Professional :: CWNA-109 Significant CWNA Changes Course rewritten from the ground up Covers the new DMG, TVHT and S1G PHYs Material is more integrated (no separation of HT topics) Site survey post-installation validation focused Less detail on security and analysis Dedicated section on troubleshooting basic Wi-Fi problems Newer solutions added older solutions removed
5 Certified Wireless Network Professional :: CWNA-109 Chapter 1: WLAN and Networking Industry Organizations Objectives Covered: 2.1 Explain the roles of WLAN and networking industry organizations 2.2 Explain the IEEE standard creation process including working groups, naming conventions, drafts and ratification
6 Certified Wireless Network Professional :: CWNA-109 Wi-Fi-Related Organizations IETF FCC and Regulatory Bodies IEEE Wi-Fi Alliance Certifies Products Set Local Regulations Creates Standards
7 Certified Wireless Network Professional :: CWNA-109 IETF Internet Engineering Task Force (IETF) Goal is to improve Internet functionality Develops and documents network technologies Request-for-Comment (RFC) documents
8 Certified Wireless Network Professional :: CWNA-109 IETF RFCs Other standards that Names of contributors add to this standard RFC Number Old versions of the standard Name of the standard
9 Certified Wireless Network Professional :: CWNA-109 Regulatory Domains Regulate radio communications in their region of the world: Available channels and frequencies Maximum transmit power Indoor/outdoor operation guidelines Accessory usage (antennas, connectors, amplifiers, etc.) Certify systems (equipment must be licensed for each domain) Examples of Regulatory domains: FCC – United States IC – Canada MIC – Japan CEPT / ECC / ETSI –Europe MIIC – China
10 Certified Wireless Network Professional :: CWNA-109 IEEE Engineering association Composed of individual members Develops LAN and MAN network standards 802.11 Specification Wireless LAN operation Data Link and Physical Layer
11 Certified Wireless Network Professional :: CWNA-109 IEEE Initial Standards Creation 802.11 Working Group • Committees • Task Groups • Ad Hoc groups Draft standard Ratified Standard
12 Certified Wireless Network Professional :: CWNA-109 IEEE Standards Lifecycle • Original Standards Specified Standards • New technologies developed Drafts • New technologies finalized as “amendments” Amendments • Original standard updated with amendments. Updated Standards
13 Certified Wireless Network Professional :: CWNA-109 IEEE Nomenclature UPPERCASE = a standard lowercase = an amendment
14 Certified Wireless Network Professional :: CWNA-109 IEEE 802.11 Timeline
15 Certified Wireless Network Professional :: CWNA-109 PHY Amendments 802.11a • Ratified in 1999 •OFDM modulation • 5 GHz frequency bands • 6-54 Mbps 802.11b • Ratified in 1999 • High-Rate DSSS (HR/DSSS) • 2.4 GHz frequency band • Backward compatible with DSSS (1 & 2 Mbps) • 5.5 and 11 Mbps 802.11g • Ratified in 2003 • Extended Rate Physical (ERP) • 2.4 GHz frequency band • Backward compatible with 802.11b (1-11 Mbps) • 6-54 Mbps 802.11n • Ratified in 2009 • Uses HT-OFDM • 2.4 & 5 GHz frequency bands • Backward compatible with 802.11a/b/g (1-54 Mbps) • Up to 600 Mbps
16 Certified Wireless Network Professional :: CWNA-109 PHY Amendments (ctd.) 802.11ad • Ratified in 2012 • 60 GHz frequency • Very High Throughput 60 GHz • Limited range • Video distribution is primary use case •Data rates 6.93Gbps 802.11ac • Ratified in 2013 • 5 GHz frequency only • Very High Throughput PHY • Backward compatible with 802.11a/n 5 GHz •Data rates 6.93Gbps 802.11af • Ratified in 2014 • 50-900 MHz frequencies • TV Whitespace • Broadband wireless applications
17 Certified Wireless Network Professional :: CWNA-109 802.11 Amendments • Operation in Additional Regulatory Domains 802.11d • Updates for compliance in some regions • Ratified in 2005 • Quality of Service (QoS) enhancements • Improves voice and video performance 802.11e • Ratified in 2003 • Dynamic Frequency Selection (DFS) • Transmit Power Control (TPC) 802.11h • Ratified in 2004 • Strong authentication with 802.1X and PSK • Strong encryption with CCMP / AES 802.11i
18 Certified Wireless Network Professional :: CWNA-109 802.11 Amendments (ctd.) • Ratified in 2004 • PHY and MAC enhancements for OFDM operation in Japan (4.9 – 5 GHz) 802.11j • Radio Resource Management • Ratified in 2008 • Radio and network measurements 802.11k • Wireless Access for Vehicular Environment • Ratified in 2012 • Aka - WAVE 802.11p • Ratified in 2008 • Fast secure roaming mechanisms, aka “Fast BSS Transition” 802.11r
19 Certified Wireless Network Professional :: CWNA-109 802.11 Amendments (ctd.) • Ratified in 2011 802.11s • Mesh networking • Ratified in 2011 • Interworking with external networks • Hotspot 2.0 enabler 802.11u • Ratified in 2011 • Wireless Network Management, using 802.11k information in client management 802.11v • Ratified in 2009 • Protected Management Frames, prevents some security vulnerabilities 802.11w
20 Certified Wireless Network Professional :: CWNA-109 Wi-Fi Alliance Device certifications Interoperability testing Whitepapers Specifications
21 Certified Wireless Network Professional :: CWNA-109 Wi-Fi Alliance Certifications Connectivity Security Access Applications and Services Optimization
22 Certified Wireless Network Professional :: CWNA-109 PoE (802.3) Ethernet cabling supplies data and power to end device Power source equipment supplies power to powered device IEEE 802.3 standard PoE Types: 802.3af (802.3-2015, Clause 33) 802.3at (802.3-2015, Clause 33)
23 Certified Wireless Network Professional :: CWNA-109 IEEE 802.1X Port-based access control: Framework for authentication of users connecting to a (W)LAN port Defines 3 Roles: Supplicant Authenticator Authentication Server Permits/denies traffic according to client’s authentication state
24 Certified Wireless Network Professional :: CWNA-109 EAP (Extensible Authentication Protocol) Flexible authentication framework Supports variety of authentication methods Many EAP protocols used in WLANs Common EAP methods: Protected EAP (PEAP) EAP-TLS EAP-FAST EAP-SIM
25 Certified Wireless Network Professional :: CWNA-109 RADIUS Remote Authentication Dial-In User Service Protocol that carries info between a network access server (AP or WLC) and authentication server to authenticate users AAA Protocol: Authentication Authorization Accounting
26 Certified Wireless Network Professional :: CWNA-109 Chapter 2: RF Characteristics and Behavior Objectives Covered: 1.1 Define and explain the basic characteristics of RF and RF behavior
27 Certified Wireless Network Professional :: CWNA-109 Electromagnetic Spectrum FM Radio Radar AM Radio Wi-Fi Light Bulb
28 Certified Wireless Network Professional :: CWNA-109 Sine Waves AMPLITUDE WAVELENGTH A B
29 Certified Wireless Network Professional :: CWNA-109 Wavelength Average physical wavelength at 2.4 GHz is 12.5 cm (4.9 in) and at 5 GHz the wavelength is 6 cm (2.36 in)
30 Certified Wireless Network Professional :: CWNA-109 Wavelength Calculation 2.4 GHz = 12.5 cm (4.92 inches) 5 GHz = 6 cm (2.36 inches) Formulas to calculate wavelength: λ (in.) = 11.811/Frequency (GHz) λ (cm) = 30/Frequency (GHz) 2.4 GHz 5 GHz
31 Certified Wireless Network Professional :: CWNA-109 Frequency LOW FREQUENCY HIGH FREQUENCY ■ Measured in Hertz (1 Hz = 1 cycle/second) 1 thousand Hz = KHz | 1 million Hz = MHz | 1 billion Hz = GHz
32 Certified Wireless Network Professional :: CWNA-109 Wavelength & Frequency Wavelength and frequency are inversely related f is frequency; is wavelength; c is the speed of light—~300,000 km/s LOW FREQUENCY LONG WAVELENGTH HIGH FREQUENCY SHORT WAVELENGTH
33 Certified Wireless Network Professional :: CWNA-109 Amplitude (Power Level) Common Units of Amplitude: Watts Milliwatts (mW) Decibels to milliwatt (dBm) Amplitude = Power Amplitude is the amount of signal energy. It is the strength or power of the signal
34 Certified Wireless Network Professional :: CWNA-109 Phase 0° 90° 180° 270° 360° 90 ° out of phase (destructive) 180 ° out of phase (cancels) In-phase (gain) Out of phase (destructive)
35 Certified Wireless Network Professional :: CWNA-109 RF Gain AMPLITUDE FREQUENCY Peak amplitude after gain Peak amplitude before gain * As viewed by oscilloscope * As viewed by spectrum analyzer Gain is the increase of RF signal strength or amplitude Active Gain: increasing power from the transmitter Passive Gain: shaping or focusing power from antenna
36 Certified Wireless Network Professional :: CWNA-109 RF Loss AMPLITUDE FREQUENCY Peak amplitude before loss Peak amplitude after loss * As viewed by oscilloscope * As viewed by spectrum analyzer Loss is a decrease in signal amplitude often due to external interference or path loss. RF Loss is caused by attenuation, absorption, and reflection
37 Certified Wireless Network Professional :: CWNA-109 Frequency Effect on Attenuation 2.4 Ghz 5 Ghz Higher frequency signals attenuate more rapidly than lower frequency signals.
38 Certified Wireless Network Professional :: CWNA-109 Reflection Reflections occur when an RF signal bounces off a smooth, non-absorptive surface, changing the direction of the signal. Reflective environments cause “multipath” Causes: Steel and metal beams, shelving, roofing, walls, furniture
39 Certified Wireless Network Professional :: CWNA-109 Refraction Refraction occurs when the RF signal passes through a medium of different density than the original medium. Refraction causes the primary wave changes direction
40 Certified Wireless Network Professional :: CWNA-109 Diffraction Diffraction is a change in the direction (bending) of RF waves after passing by or through an obstacle RF Shadow Diffracted Path Rooftop Aerial View
41 Certified Wireless Network Professional :: CWNA-109 Scattering Scattering is a type of reflection caused by uneven surfaces and increases echoes and multipath. Causes: Steel and metal beams, shelving, roofing, walls, furniture
42 Certified Wireless Network Professional :: CWNA-109 Absorption Dense materials absorb RF energy as the signal passes through, decreasing amplitude. Causes: Brick and concrete, drywall, windows, doors, people, water, etc. Weaker signal results from absorption RF is absorbed
43 Certified Wireless Network Professional :: CWNA-109 Heatmap Showing Absorption Signal is absorbed by the walls
44 Certified Wireless Network Professional :: CWNA-109 Multipath and Delay Spread Wall
45 Certified Wireless Network Professional :: CWNA-109 Interference (Corruption) Interference is anything that corrupts or modifies the original signal (usually destructive) such as nonWi-Fi transmitters, Multipath fading, co-channel and adjacent-channel Wi-Fi devices. Wave 1 Wave 2 Combined
46 Certified Wireless Network Professional :: CWNA-109 RF Propagation Waves move away from the source. Similar to the waves created by a rock being thrown into a calm lake Objects in the waves path (trees, buildings, hills) affect the wave As the wave moves away from the source: It becomes broader It becomes weaker Newton’s Inverse Square Law Change in power = 1 divided by the square of the change in distance Free Space Path Loss (FSPL)
47 Certified Wireless Network Professional :: CWNA-109 Free Space Path Loss (FSPL) FSPL Free Space Path Loss is a measure of how much signal remains with increasing distance in free space (approximately same as air)
48 Certified Wireless Network Professional :: CWNA-109 RF in the Time Domain
49 Certified Wireless Network Professional :: CWNA-109 RF in the Frequency Domain
50 Certified Wireless Network Professional :: CWNA-109 Spread Spectrum FREQUENCY AMPLITUDE Spread Spectrum Narrowband FREQUENCY AMPLITUDE Frequency Hopping Spread Spectrum (FHSS) Direct Sequence Spread Spectrum (DSSS) Spreads an RF signal across more bandwidth than is necessary for the amount of the data. Resists narrowband interference