Wireless Networks

Question 1

Wireless Frequencies

Answer 1

■ Refer to different frequency bands used to transmit and receive radio
waves in wireless networks
■ Each frequency band has specific characteristics related to speed,
coverage, and regulations to prevent interference

Question 2

2.4 GHz Band

Answer 2

■ Widely used since 1997
■ Long-range and better penetration through solid objects
■ Contains frequencies from 2.400 GHz to 2.495 GHz
■ Divided into channels with overlapping, causing interference
● Up to channel 11 to 14
● Channel
○ Physical medium through which wireless networks can
send and receive data

○ Channels that do not overlap that are advisable for use to
avoid interference:
■ Channel 1
■ Channel 6
■ Channel 11

Question 3

5 GHz Band

Answer 3

■ Offers faster data transfer speeds with shorter range compared to 2.4
GHz
■ Contains frequencies from 5.7 GHz to 5.875 GHz, providing up to 24
non-overlapping channels
■ Channel Bonding
● Creates a wider channel by merging two or more neighboring
channels into a single wider channel
● Increases bandwidth but becomes more susceptibility to
interference due to increased channel widths

Question 4

6 GHz Band

Answer 4

■ Newest spectrum for wireless networking, offering more channels and
bandwidth
■ Frequencies range from 5.925 GHz to 7.125 GHz, providing faster
connections with less congestion
■ Allows for channels of 20, 40, 80, or 160 MHz in width, accommodating
up to 59 channels.

Question 5

Important Exam Points (Wireless Networks)

Answer 5

Supported frequencies
● 2.4 GHz – b, g, n, and ax

● 5 GHz – a, n, ac, or ax

● 6 GHz – ax

■ Higher speeds often come with reduced coverage distances for a single
access point
■ Check considerations for compatibility and frequency bands in
troubleshooting scenarios
■ Caution against relying on marketing materials for exam answers
■ Stick to official standards

Question 6

Wireless ax (802.11ax/Wi-Fi 6)

Answer 6

■ Frequency band – 2.4 GHz, 5 GHz, and 6 GHz (Wi-Fi 6e)
■ Speed – up to 9.6 Gbps
■ Utilizes MU-MIMO technology for enhanced simultaneous user access
■ Fully backwards compatible with previous standards

Question 7

Wireless ac (802.11ac/Wi-Fi 5))

Answer 7

■ Frequency band – 5 GHz
■ Speed – up to 6.9 Gbps or more
■ Multiple-User Multiple-Input Multiple-Output (MU-MIMO)
● Multipath wireless communication technology that allows
multiple users to access the wireless network and access the
access point at the same time
● Acts like a switch

Question 8

■ Multiple-Input Multiple-Output (MIMO)

Answer 8

● Technology that allows access point to use multiple antennas to
send and receive data at faster speeds than it could with a single
antenna
● Acts like a hub

Question 9

Wireless n (802.11n/Wi-Fi 4)

Answer 9

■ Frequency band
● 5 GHz
○ Speed – up to 600 Mbps
○ Range – about 35 meters
● 2.4 GHz
○ Speed – up to 300 Mbps
○ Range – upt to 70 meters
■ Introduced to meet demands for faster networking speeds

Question 10

Wireless g (802.11g)

Answer 10

■ Frequency band – 2.4 GHz
■ Speed – up to 54 Mbps
■ Range – around 140 meters
■ Offers similar speed and range as Wireless a but utilizes cheaper
frequency bands

Question 11

Wireless b (802.11b)

Answer 11

■ Frequency band – 2.4 GHz
■ Speed – initially 11 Mbps
■ Range – about 140 meters
■ Developed to be cheaper and more accessible than Wireless a, leading to
widespread adoption

Question 12

IEEE 802.11 Standard

Answer 12

■ Defines technologies for wireless local area network (WLAN)
communication
■ Evolved over time to meet demands for faster data transfer speeds and
more reliable networks

Question 13

Key Tips for Exam

Answer 13

■ Open networks – no security measures
■ WEP – Initialization Vector (IV) vulnerabilities
■ WPA – linked with teacup and RC4 encryption
■ WPA2 – uses CCMP for integrity and AES for encryption
■ WPA3 – introduces SAE and dragonfly key exchange
■ WPS – involves push-button configuration but should be disabled for
security
■ Pre-shared key – personal mode authentication
■ Enterprise mode – individual user authentication via centralized server
(e.g., RADIUS with 802.1X)

Question 14

Wi-Fi Protected Access 2 (WPA2)

Answer 14

● Replaced WPA due to vulnerabilities, introduced in 2004 as part of
the 802.11i standard
● Offers stronger integrity checking, better encryption, and
improved authentication
● CCMP
○ Countermode with Cipher Blockchaining Message
Authentication Code Protocol for enhanced security
○ Combines message integrity checks with comprehensive
encryption protocols for confidentiality and integrity
assurance
● Advanced Encryption Standard (AES)
○ Replaced the less secure RC4 encryption algorithm
○ 128-bit
■ Most WPA2 networks use for security and
confidentiality
○ 192-bit
○ 256-bit
● Personal mode – with pre-shared key, common in home or small
office networks
● Enterprise mode – preferred for larger environments, utilizing
centralized authentication servers for user validation