Wireless Flashcards
The standard channel size for 2.4 GHz and 5 GHz wireless networks?
20 MHz channel size
Channel Bonding
Allows for the creation of a wider wireless channel by merging neighboring channels into one.
Channel
A virtual medium through which wireless networks can send and receive data
Which wireless channels should be used to avoid overlapping frequencies in the 2.4 GHz band?
1, 6, and 11
What is the standard size for wireless channels in 2.4 and 5 GHz networks?
20 MHz
Multipl-Input and Multiple-Output (MIMO)
Uses multiple antennas to send and receive more data than it could with a single antenna
Multiple User Multipl-Input and Multiple-Output (MU-MIMO)
Allows multiple users to access the wireless network and access point at the same time
Goefencing
Uses GPS or RFID to define real-world boundaries where barrier can be active or passive
Rogue Access Point
A fake ap set up to lure legitimate users to connect and capture all the packets going through
Evil Twin
War Driving
Occurs when users perform reconnaissance looking for unsecured wireless networks
802.11a
5 GHz
54 Mbps
80211.b
2.4 GHz
11 Mbps
802.11g
2.4 GHz
54 Mbps
802.11n
2.4 and 5 GHz
150 Mbps / 600 Mbps (MIMO)
(Wi-Fi 4)
802.11ac
5 GHz
6.9 Gbps (MU-MIMO)
(Wi-Fi 5)
802.11ax
2.4, 5, and 6 GHz
9.6 Gbps
(Wi-Fi 6)
Support 2.4 GHz
802.11b
802.11g
802.11n
802.11ax
Support 5 GHz
802.11a
802.11n
802.11ac
802.11ax
Dual band standards
802.11n
802.11ax
Open
No security or protection
WEP
Initialization vector, flaw in WEP
Weak don’t use
WPA
*TKIP
*RC4 encryption
*Weak don’t use
WPA2
CCMP
AES encryption
Received Signal Strength Indicator (RSSI)
Signal strength as measured at the receiver, using either decibel units or an index value.
Direct-Sequence Spread Spectrum (DSSS)
Frequency-Hopping Spread Spectrum (FHSS)
Orthogonal Frequency Division Multiplexing (OFDM)
Quadrature Amplitude Modulation (QAM)
Quadrature Phase-shift keying (PSK).
Methods of wireless modulation
Sprea Spectrum
Orthogonal
Quadrature
Received Signal Strength Indication (RSSI)
Estimated measure of the power level that a radio frequency client device is receiving from a wireless access point or wireless router
Effective Equivalent Isotropic Radiated Power (EIRP)
Maximum power radiated from an ideal isotropic antenna, given its antenna gain, and the transmitter power of the radio frequency system
Vertical Antenna
Radio frequency waves extend outward in all directions away from the antenna and the wireless access point at an equal power level
Dipole Antenna
Produces radio frequency waves extending outward in two directions
Yagi Antenna
A unidirectional antenna that sends the radio frequency waves in only one direction
Parabolic Grid Antenna
Allows the radio waves to be transmitted in only one direction over a longer distance than a Yagi antenna
Polarization
The orientation of the electric field (or transmission) from the antenna
Channel Utilization
A statistic or measure of the amount of airtime utilization for a particular frequency or channel
Clear Channel Assessment (CCA)
Listens to see if another device is actively transmitting on the channel before attempting to send frames on the channel
Site Survey
Process of planning and designing a wireless network to provide the required wireless solution
Multipath Reception
Occurs when the transmitted signal bounces off walls and other physical objects and then is redirected to the receiver
HTTP Redirect
Redirects all traffic to a web server which then redirects them to a captive portal using a 302 HTTP status code
5G comes in three bands. Low, Mid, and High. Higher is faster but smaller range.
5G comes in three bands. Low, Mid, and High. Higher is faster but smaller range.
Code-Division Multiple Access
A cellular technology that uses code division to split up the channel.
Global System for Mobile Communications
A cellular technology that takes the voice during a call then converts it to digital data.
Microwave/Worldwide Interoperability for Microwave Access (WiMax)
Uses a beam of radio waves in the microwave frequency range to transmit information between two fixed location.
Ad-Hoc Mode
Each wireless device communicates directly to another, without the need of a centralized access point.
Infrastructure Mode
All wireless devices communicate through a centralized access point or router.
Mesh Topology
Uses a combination of different wireless networks such as Wi-Fi, microwave, cellular, and more.
Range Extender
Specialized device that overcomes distance limitation of wireless networks.
2.4 GHz
- Better at propagating through solid surfaces, longer signal range.
- Does not support high number of channels
- Often congested, by other Wi-Fi and other wireless technology
- Increased risk of interference,
- Data rates typically lower than 5 GHz.
5 GHz
- Less effective at penetrating solid surfaces and doesn’t support the max ranges achieved with 2.4 GHz
- Supports more channels
- Suffers less from congestion and interference
- Higher data rates at shorter ranges.
- 25 non-overlapping channels
3G
- GPRS/EDGE (General Packet Radio Services/Enhanced Data Rates for GSM Evolution)
- HSPA+ (Evolved High Speed Packet Access)
- EV-DO (CDMA2000/Evolution Data Optimized)
4G
- LTE Long Term Evolution
- LTE-A LTE Advanced
NFC (Near Field Communication)
- Communication protocols between two devices at 4 cm or less
- Used with payment systems like Apple Pay
- Supports two-way communication
- Low-speed connection with a simple setup that can bootstrap more capable wireless connections.
Bluetooth
- Sshort-range wireless technology standard
- Used for exchanging data between fixed and mobile devices over short distances
- Use UHF radio waves in the ISM band from 2.402 GHz to 2.48 GHz
- Used to create peer-to-peer connections between two devices for a distance of up to 10 meters
