802.11n ==================== .. toctree:: :maxdepth: 1 :hidden: :includehidden: 802_11n/802_11n 802_11n/mac_functions 802_11n/mac_timings 802_11n/packet_formats 802_11n/power_save 802_11n/interoperability 802_11n/physical_rates 802_11n/ppdu 802_11n/channels 802_11n/PHYs IEEE 802.11n is a Wi-Fi standard that improves speed, range, and reliability by using MIMO (Multiple Input, Multiple Output) technology and channel bonding to achieve data rates up to 600 Mbps. .. list-table:: :widths: 20 60 20 :header-rows: 1 * - Category - Description - Use Case * - MAC Functions - Enhanced MAC layer with support for frame aggregation (A-MPDU, A-MSDU), Block ACK, and QoS improvements. - Efficient data handling and improved throughput in wireless networks * - MAC Timings - Includes refined timing for frame exchanges, Block ACK sessions, and channel access coordination. - Reducing overhead and improving efficiency in data-heavy applications * - Packet Formats - Defines updated frame structures to support aggregation and HT-specific information elements. - Supporting high-throughput (HT) operations and enhanced signaling * - Power Save - Includes legacy PSM and introduces Spatial Multiplexing Power Save (SMPS) to save power during MIMO operations. - Energy efficiency in mobile devices while using multiple antennas * - Interoperability - Ensures backward compatibility with 802.11a/b/g and coexistence via protection mechanisms. - Smooth integration with existing Wi-Fi networks and legacy devices * - Physical Rates - Supports MCS 0–31 with data rates up to 600 Mbps using 4 spatial streams and 40 MHz channels. - High-speed data transfer in dense wireless environments * - PPDU - Defines HT-PPDU format including HT-SIG, HT-STF, and HT-LTF for MIMO support. - Enabling reliable high-throughput communication using advanced PHY techniques * - Channels - Operates on 2.4 GHz and 5 GHz bands with 20 MHz and optional 40 MHz wide channels. - Flexible frequency use and channel bonding for higher throughput * - PHY Overview - MIMO-based Physical Layer using OFDM, multiple spatial streams, short GI, and channel bonding. - Achieving high throughput and robust wireless performance in multipath environments .. tab-set:: .. tab-item:: 802.11n Basics **Standard:** IEEE 802.11n (2009) **Main Features:** - Introduced MIMO (Multiple Input Multiple Output) for higher throughput - Operates in both 2.4 GHz and 5 GHz bands (dual-band) - Supports channel bonding (20/40 MHz) to double bandwidth - Improves signal reliability and range via spatial streams - Enables data rates up to 600 Mbps - Backward compatible with 802.11a/b/g **Use Cases:** - Home and enterprise wireless networking - High-speed internet access over Wi-Fi - Streaming media (HD video, VoIP, gaming) - Office and campus environments needing improved range and capacity **Related Concepts:** - MIMO antenna systems - Channel bonding and interference - Spatial multiplexing - Frame aggregation (A-MSDU, A-MPDU) - Backward compatibility handling .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the foundational concepts of 802.11n:** * :ref:`Learnings in this section <802_11n_step1>` * :ref:`Terminology <802_11n_step2>` * :ref:`Version Info <802_11n_step3>` * :ref:`802_11n Version&IEEE Details <802_11n_step4>` * :ref:`802_11n Basic Setup on Ubuntu using IPv4 <802_11n_step5>` * :ref:`802_11n Basic Setup on Ubuntu using IPv6 <802_11n_step6>` * :ref:`Reference links <802_11n_step16>` .. button-link:: ./802_11n/802_11n.html :color: primary :shadow: :expand: Jump to "802.11n Basics" .. tab-set:: .. tab-item:: 802.11n MAC Functions **Standard:** IEEE 802.11n (2009) **Main Features:** - Enhances MAC efficiency through frame aggregation (A-MSDU and A-MPDU) - Introduces Block Acknowledgment (Block ACK) for grouped frame acknowledgment - Supports QoS via Enhanced Distributed Channel Access (EDCA) - Enables high-throughput (HT) operations with optimized control signaling - Implements improved error recovery mechanisms for reliable delivery - Works in coordination with MIMO at PHY layer for performance optimization **Use Cases:** - Supporting high-throughput applications like HD video streaming and VoIP - Reducing overhead in dense WLAN deployments - Improving MAC efficiency for bursty and high-volume traffic patterns **Related Functions:** - A-MSDU and A-MPDU aggregation techniques - Block ACK setup, teardown, and operation - HT Control field and QoS control enhancements - Retry limit and backoff control mechanisms .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11n MAC Functions:** * :ref:`Reference links ` .. button-link:: ./802_11n/mac_functions.html :color: primary :shadow: :expand: Jump to "802.11n MAC Functions" .. tab-set:: .. tab-item:: 802.11n MAC Timings **Standard:** IEEE 802.11n (2009) **Main Features:** - Builds on legacy MAC timing mechanisms like SIFS and DIFS - Introduces support for Block Acknowledgments to reduce overhead - Enables frame aggregation (A-MPDU, A-MSDU) with optimized timing - Supports reduced interframe spacing (RIFS) to improve efficiency - Improves timing coordination in MIMO environments - Integrates with QoS enhancements through HCF and EDCA timing rules **Use Cases:** - Enhancing throughput by reducing timing gaps between frames - Supporting high-speed multimedia and VoIP over Wi-Fi - Improving transmission efficiency in dense or high-traffic networks **Related Timing Parameters:** - Short Interframe Space (SIFS) - Distributed Interframe Space (DIFS) - Reduced Interframe Space (RIFS) - Contention window and AIFS for QoS scheduling .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11n MAC Timings:** * :ref:`Reference links ` .. button-link:: ./802_11n/mac_timings.html :color: primary :shadow: :expand: Jump to "802.11n MAC Timings" .. tab-set:: .. tab-item:: 802.11n Packet Formats **Standard:** IEEE 802.11n (2009) **Main Features:** - Defines enhanced MAC and PHY layer frame structures to support high throughput - Includes standard 802.11 frame fields with additional support for QoS and HT Control - Supports frame aggregation (A-MSDU and A-MPDU) to reduce overhead - Uses High Throughput (HT) PHY format with added HT-SIG field - Introduces new control mechanisms for MIMO transmission and Block ACK - Enables compatibility with legacy 802.11a/b/g devices through dual-format operation **Use Cases:** - Efficient handling of large data transfers over WLANs - Reducing overhead for latency-sensitive applications like VoIP and streaming - Supporting higher throughput and better network utilization in enterprise environments **Related Frame Types:** - Aggregated MSDU (A-MSDU) and Aggregated MPDU (A-MPDU) - HT-specific control frames and extended Block ACK - QoS Data frames with prioritization support .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11n Packet Formats:** * :ref:`Reference links ` .. button-link:: ./802_11n/packet_formats.html :color: primary :shadow: :expand: Jump to "802.11n Packet Formats" .. tab-set:: .. tab-item:: 802.11n Power Saving Mechanisms **Standard:** IEEE 802.11n (2009) **Main Features:** - Enhances legacy Power Save Mode (PSM) with new features like Unscheduled Automatic Power Save Delivery (U-APSD) - Supports both Scheduled and Unscheduled power save delivery for improved efficiency - Introduces Power Save Multi-Poll (PSMP) for scheduled transmissions in QoS networks - AP buffers traffic and delivers during pre-negotiated Service Periods (SPs) - Optimized for high-throughput and low-latency environments using WMM-Power Save - Maintains backward compatibility with 802.11a/b/g power save modes **Use Cases:** - Battery-efficient high-speed Wi-Fi for smartphones and tablets - Power-aware multimedia streaming and VoIP - Improved sleep scheduling in enterprise and IoT Wi-Fi deployments **Related Mechanisms:** - U-APSD and PSMP protocols - Service Period scheduling and management - QoS-aware power save using WMM (Wi-Fi Multimedia) .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11n Power Saving mechanisms:** * :ref:`Reference links ` .. button-link:: ./802_11n/power_save.html :color: primary :shadow: :expand: Jump to "802.11n Power Saving" .. tab-set:: .. tab-item:: 802.11n Interoperability **Standard:** IEEE 802.11n (2009) **Main Features:** - Ensures backward compatibility with 802.11a/b/g devices using legacy modes - Supports operation in both 2.4 GHz and 5 GHz bands via dual-band capability - Mixed mode operation allows simultaneous use of HT (High Throughput) and legacy clients - Introduces protection mechanisms like RTS/CTS and dual CTS to prevent collisions with legacy devices - Maintains standardized MAC and PHY formats for consistent communication - Facilitates integration with existing Wi-Fi infrastructures and standards **Use Cases:** - Deploying 802.11n in environments with existing 802.11a/b/g networks - Smooth migration path from older Wi-Fi standards to high-throughput 802.11n - Supporting multi-generation devices in enterprise, public, and home Wi-Fi **Related Mechanisms:** - Legacy protection using RTS/CTS and CTS-to-Self - Use of 20/40 MHz coexistence mechanisms - Interworking via Beacon and Capability Information fields .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11n Interoperability mechanisms:** * :ref:`Reference links ` .. button-link:: ./802_11n/interoperability.html :color: primary :shadow: :expand: Jump to "802.11n Interoperability" .. tab-set:: .. tab-item:: 802.11n Physical Rates **Standard:** IEEE 802.11n (2009) **Main Features:** - Supports physical layer data rates from 6.5 Mbps up to 600 Mbps - Uses MIMO (Multiple Input, Multiple Output) technology to increase throughput - Employs OFDM modulation with 64 subcarriers over 20 MHz or 40 MHz channels - Supports up to 4 spatial streams (each adding throughput) - Utilizes Modulation and Coding Schemes (MCS index 0–31) for rate flexibility - Offers dynamic rate adaptation based on channel quality and client capability **Use Cases:** - High-throughput applications like HD video streaming and large file transfers - Enterprise-grade WLANs with high device density - Performance-demanding environments such as hospitals, schools, and offices **Related Concepts:** - MIMO and Spatial Multiplexing - MCS Index Table (Rate vs. Spatial Stream vs. Channel Width) - Short Guard Interval (SGI) to reduce inter-symbol interference - 20/40 MHz channel bonding for wider bandwidth and higher speed .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11n Physical Rates:** * :ref:`802.11 n 5MHz ` * :ref:`802.11 n 10MHz ` * :ref:`802.11 n 20MHz - EQM - MCS 0-31 - Short Gaurd Interval ` * :ref:`802.11 n 20MHz - EQM - MCS 0-31 - Long Gaurd Interval ` * :ref:`802.11 n 20MHz - UEQM - MCS 32-76 - Short Gaurd Interval ` * :ref:`802.11 n 20MHz - UEQM - MCS 32-76 - Long Gaurd Interval ` * :ref:`802.11 n 40MHz - EQM - MCS 0-31 - Short Gaurd Interval ` * :ref:`802.11 n 40MHz - EQM - MCS 0-31 - Long Gaurd Interval ` * :ref:`802.11 n 40MHz - UEQM - MCS 32-76 - Short Gaurd Interval ` * :ref:`802.11 n 40MHz - UEQM - MCS 32-76 - Long Gaurd Interval ` * :ref:`Reference links ` .. button-link:: ./802_11n/physical_rates.html :color: primary :shadow: :expand: Jump to "802.11n Physical Rates" .. tab-set:: .. tab-item:: 802.11n PPDU **Standard:** IEEE 802.11n (2009) **Main Features:** - Defines the PPDU (Physical Protocol Data Unit) structure for 802.11n transmissions - Supports both Legacy (compatible with 802.11a/g) and HT (High Throughput) formats - HT-format includes HT-SIG, HT-STF, HT-LTF, and DATA fields - Enables MIMO transmission with multiple spatial streams - Uses channel bonding (20/40 MHz) for enhanced throughput - Incorporates short guard interval (SGI) and aggregation features **Use Cases:** - Efficient data encapsulation for high-throughput Wi-Fi communication - Synchronization and channel estimation in multi-antenna environments - Supporting backward compatibility and advanced features like MIMO **Related Concepts:** - Greenfield and Mixed PPDU formats - HT-SIG (High Throughput Signal) field - Aggregated MPDU (A-MPDU) support at PHY level - Preamble training sequences for MIMO decoding .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11n PPDU:** * :ref:`Reference links ` .. button-link:: ./802_11n/ppdu.html :color: primary :shadow: :expand: Jump to "802.11n PPDU" .. tab-set:: .. tab-item:: 802.11n Channels **Standard:** IEEE 802.11n (2009) **Main Features:** - Operates in both 2.4 GHz and 5 GHz bands (dual-band support) - Supports 20 MHz and optional 40 MHz wide channels for increased throughput - Up to 23 non-overlapping 20 MHz channels in 5 GHz (varies by region) - Channel bonding (40 MHz) can double the effective channel width - Uses both static and dynamic channel allocation with DFS and TPC (especially in 5 GHz) - Designed for high data rates with MIMO and spatial multiplexing **Use Cases:** - Deploying high-throughput Wi-Fi in both residential and enterprise networks - Enhancing throughput by using 40 MHz bonded channels in 5 GHz band - Supporting bandwidth-intensive applications (e.g., video streaming, conferencing) **Related Concepts:** - MIMO (Multiple Input Multiple Output) and Spatial Streams - Channel bonding (20/40 MHz) and its effect on interference - DFS (Dynamic Frequency Selection) and TPC (Transmit Power Control) - Compatibility with legacy 802.11a/b/g networks .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11n Channels:** * :ref:`List of channels ` * :ref:`List of channel widths ` * :ref:`List of Bands ` * :ref:`Reference links ` .. button-link:: ./802_11n/channels.html :color: primary :shadow: :expand: Jump to "802.11n Channels" .. tab-set:: .. tab-item:: 802.11n PHY **Standard:** IEEE 802.11n (2009) **Main Features:** - Introduces MIMO (Multiple Input Multiple Output) for spatial multiplexing - Supports data rates up to 600 Mbps (with 4 spatial streams and 40 MHz channels) - Operates in both 2.4 GHz and 5 GHz bands - Offers channel bonding: 20 MHz or 40 MHz channel widths - Uses OFDM with 64 subcarriers (same as 802.11a/g) - Employs convolutional coding, interleaving, and optional LDPC for error correction - Introduces Short Guard Interval (400 ns) for improved efficiency **Use Cases:** - High-throughput Wi-Fi for HD streaming, gaming, and large data transfers - Enterprise wireless deployments requiring stable and fast connections - Improved performance in environments with multipath interference **Related Concepts:** - MIMO, spatial streams, and antenna configurations - Channel bonding and its trade-offs - Short Guard Interval (SGI) and its impact on throughput - Frame aggregation (A-MPDU, A-MSDU) and PHY enhancements .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11n PHY:** * :ref:`Reference links ` .. button-link:: ./802_11n/PHYs.html :color: primary :shadow: :expand: Jump to "802.11n PHY"