Next Generation Wireless LANs: 802.11n and 802.11ac
If you've been searching for a way to get up to speed on IEEE 802.11n and 802.11ac WLAN standards without having to wade through the entire specification, then look no further. This comprehensive overview describes the underlying principles, implementation details and key enhancing features of 802.11n and 802.11ac. For many of these features the authors outline the motivation and history behind their adoption into the standard. A detailed discussion of key throughput, robustness, and reliability enhancing features (such as MIMO, multi-user MIMO, 40/80/160 MHz channels, transmit beamforming and packet aggregation) is given, plus clear summaries of issues surrounding legacy interoperability and coexistence. Now updated and significantly revised, this 2nd edition contains new material on 802.11ac throughput, including revised chapters on MAC and interoperability, plus new chapters on 802.11ac PHY and multi-user MIMO. An ideal reference for designers of WLAN equipment, network managers, and researchers in the field of wireless communications.
Why Read This Book
You will get a concise, engineering‑focused tour of the key PHY and MAC advances that made 802.11n and 802.11ac high‑throughput WLANs possible, with explanations of the motivations, algorithms and implementation tradeoffs. The book emphasizes how MIMO, OFDM, channel bonding, beamforming and aggregation interact to affect throughput and robustness, so you can connect DSP and system design decisions to real‑world Wi‑Fi performance.
Who Will Benefit
Practicing communications and DSP engineers (or advanced students) who need a practical, standards‑aware understanding of 802.11n/ac PHY and MAC mechanisms to design, simulate, or debug Wi‑Fi systems.
Level: Intermediate — Prerequisites: Basic digital communications and signal processing (OFDM fundamentals, modulation, SNR concepts), familiarity with linear algebra and basic probability/statistics.
Key Takeaways
- Explain the PHY building blocks of 802.11n/ac (OFDM numerology, modulation/coding, FFT usage) and how they affect spectral efficiency.
- Analyze MIMO and MU‑MIMO concepts including spatial streams, channel sounding, and practical beamforming strategies.
- Evaluate the throughput and coexistence tradeoffs introduced by channel bonding (40/80/160 MHz) and packet aggregation.
- Assess implementation issues such as backward compatibility, legacy coexistence, and real‑world RF/system constraints.
- Apply performance metrics and measurement considerations to estimate real WLAN capacity under different propagation and traffic scenarios.
Topics Covered
- Introduction and evolution of IEEE 802.11 standards
- WLAN system architecture and design goals
- PHY fundamentals: OFDM, subcarriers, cyclic prefix, and FFT
- Modulation, coding, and rate adaptation in 802.11n/ac
- MIMO fundamentals: spatial multiplexing, diversity and STBC
- Transmit beamforming and channel sounding techniques
- Multi‑user MIMO (MU‑MIMO) and scheduling implications
- Channel bonding and wideband operation (40/80/160 MHz)
- MAC enhancements: aggregation, block ACKs, and rate control
- Interoperability, legacy coexistence, and deployment issues
- Performance analysis and measurement methodology
- Implementation challenges, PHY/MAC tuning, and future directions
Languages, Platforms & Tools
How It Compares
More focused on the PHY/MAC advances of 802.11n/ac than Matthew Gast's general 802.11 guides; more accessible than the full IEEE spec while more technically detailed on MIMO/beamforming than broad WLAN overviews.
