Wireless networking enables devices to connect and communicate over radio frequencies without physical cables, forming the backbone of modern mobile connectivity in homes, enterprises, and public spaces. Built on the IEEE 802.11 family of standards and operating primarily in the 2.4 GHz, 5 GHz, and 6 GHz bands, Wi-Fi has evolved from basic 11 Mbps connections (802.11b) to multi-gigabit speeds exceeding 30 Gbps (Wi-Fi 7). Understanding wireless networking requires balancing three competing priorities: coverage area, throughput capacity, and interference management—because radio spectrum is a shared, finite resource where every transmitted frame consumes airtime that cannot be reused by nearby devices. The key mental model: think of wireless as a half-duplex shared medium where hidden nodes, co-channel contention, and signal attenuation create challenges that wired networks never face.
What This Cheat Sheet Covers
This topic spans 13 focused tables and 111 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
Table 1: Wi-Fi Standards (802.11 Amendments)
The 802.11 family is a sprawling alphabet of amendments, and they fall into two camps worth keeping straight: the data-rate generations everyone markets as Wi-Fi 4 through 7 (n, ac, ax, be), and the quieter letter amendments (r, k, v, w, h, s) that add roaming, frame protection, and spectrum-sharing behavior on top. Knowing which standard introduced which capability—MIMO, OFDMA, 320 MHz channels—tells you what a given access point can actually do.
| Standard | Example | Description |
|---|---|---|
Max 9.6 Gbps, 2.4/5/6 GHz | • Adds OFDMA, MU-MIMO downlink/uplink, BSS coloring, TWT for dense environments • 6E variant includes 6 GHz band access | |
Max 30+ Gbps, 320 MHz channels | Introduces 4096-QAM, Multi-Link Operation (MLO), preamble puncturing for ultra-high throughput and low latency. | |
Max 6.9 Gbps, 5 GHz only | • First standard with 160 MHz channels, 256-QAM, up to 8 spatial streams • backward compatible with 802.11n devices | |
Max 600 Mbps, 2.4/5 GHz | • Introduced MIMO (up to 4x4), 40 MHz channels, frame aggregation • first dual-band standard with significant speed improvements | |
Max 54 Mbps, 2.4 GHz | • Uses OFDM modulation in 2.4 GHz • backward compatible with 802.11b but suffers performance degradation in mixed environments | |
<50ms roaming handoff | • Enables pre-authentication with target AP before roaming • reduces handoff time from 200-400ms to under 50ms for VoIP/video | |
Radio resource measurement | Provides neighboring AP information to clients for intelligent roaming decisions without excessive scanning. |