2.0 Networking Implementations
2.4 Wireless Standards and Technologies
802.11 Standards
a - 5 GHz, 54 mbps, 20 MHz bandwidth
b - 2.4 GHz, 11 mbps, 22 MHz bandwidth
g - 2.4 GHz, 54 mbps, 20 MHz bandwidth
n (WiFi 4) - 2.4 or 5 GHz, 150 mbps/channel, MIMO (Multi-In, Multi-Out), 4 streams
20, 40, 80 MHz bandwidth
ac (WiFi 5) - 5 GHz, 867 mbps/channel, channel bonding, Multi-user MIMO, 8 streams
20, 40, 80, 80+80, 160 MHz bandwidth
ax (WiFi 6) - 4 and 5 GHz, 1.2 gbps/channel, channel bonding, MU-MIMO, 8 streams
20, 40, 80, 80+80, 160 MHz bandwidth
Frequencies and range
2.4 GHz - 20 MHz channels: 1, 6, 11, between 2,412 - 2482 MHz bandwidth
5 GHz - 20, 40, 80, 160 MHz, many channels
Channels - Designated frequencies assigned by the IEEE
Regulatory Impacts - Legal restrictions on specific channels/frequencies
Channel Bonding - Combining channels together to create a wider frequency range.
Service Set Identifier (SSID) - Wireless broadcast connection name
Basic Service Set (BSSID) - Wireless Access Point (WAP) physical address (similar to MAC).
Extended Service Set (ESSID) - Multiple WAPs setup to extend the coverage of a wireless signal.
Independent Basic Service Set (Ad-hoc, IBSS) - Direct communication between devices without using a WAP, often used as an unplanned, temporary setup.
Roaming - Auto switching between WAPs to maintain network connectivity.
Antenna Types
Omni - Signal distributed evenly in each direction.
Directional - Signal focused towards a single direction.
Encryption Standards
WiFi Protected Access (WPA) - Legacy, transitional from WEP, RC4 cipher to be compatible with old hardware, introduced in 2002.
WPA2 Personal - Uses block mode of encryption known as CCMP (Counter Mode with Cipher Block Chaining Message Authentication Code Protocol), introduced in 2004.
Advanced Encryption Standard (AES) - Uses GMAC (Galois Message Authentication Code), introduced with WPA3 in 2018
Temporal Key Integrity Protocol (TKIP) - RC4 cipher, larger Initialization Vector (IV), encrypted hash communications being sent over network.
Cellular Technologies
Code-Division Multiple Access (CDMA) - Original 2G standard, Used a code to send and filter multiple streams of data at once (Verizon and Sprint).
Global System for Mobile Communications (GSM) - Original 2G standard, used multiplexing to send/receive multiple streams of data at once (EU, AT&T, T-Mobile).
Long-Term Evolution (LTE) - Merge standard used to converge previous standards into a single shared standard.
3G, 4G, 5G - Mobile network generations, continuously improved speeds, bandwidths, and connectivity.
Multiple Input, Multiple Output (MIMO) - Multiple wireless channels used together to support higher data transfer rates.
Multi-User MIMO (MU-MIMO) - MIMO available to multiple users at the same time.