802.11an
=============

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   802_11an/802_11an
   802_11an/mac_functions
   802_11an/mac_timings
   802_11an/packet_formats
   802_11an/power_save
   802_11an/interoperability
   802_11an/physical_rates
   802_11an/ppdu

IEEE 802.11an is an amendment to the Wi-Fi standard that extends 802.11a operation to wider 40 MHz channels in the 5 GHz band, enabling higher data rates up to 300 Mbps.

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   * - Category
     - Description
     - Use Case
   * - MAC Functions
     - Core MAC layer responsibilities like frame delimiting, addressing, error checking.
     - Managing wireless communication and reliable data delivery
   * - MAC Timings
     - Timing parameters like SIFS, DIFS, backoff timers controlling transmission.
     - Coordination of medium access and collision avoidance
   * - Packet Formats
     - Structure of 802.11an frames including header, payload, and control frames.
     - Frame parsing and network management
   * - Power Save
     - Power saving mechanisms allowing devices to enter low power modes.
     - Extending battery life while maintaining connectivity
   * - Interoperability
     - Mechanisms for compatibility with other 802.11 standards and vendors.
     - Seamless multi-vendor and multi-standard network operation
   * - Physical Rates
     - Supported data rates and modulation schemes of 802.11an, utilizing 40 MHz channels in 5 GHz.
     - Higher throughput and efficient spectrum use with wider channels
   * - PPDU
     - Physical Protocol Data Unit format including extended preamble and data fields for 40 MHz operation.
     - Synchronization and efficient data transmission over wider channels


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   .. tab-item:: 802.11an MAC Functions

      **Standard:** IEEE 802.11an (2007)

      **Main Features:**

      - Core MAC responsibilities including frame delimiting, addressing, and error detection
      - Ensures reliable wireless communication and handles retransmissions
      - Manages medium access control with CSMA/CA for 5 GHz band using 40 MHz channels
      - Controls acknowledgments (ACK) and fragmentation/reassembly of frames
      - Supports enhanced throughput with wider channels and efficient spectrum use
      - Integrates closely with Physical Layer features unique to 802.11an

      **Use Cases:**

      - Delivering high-speed Wi-Fi connectivity in 5 GHz band with 40 MHz channels
      - Managing medium access for increased throughput WLAN deployments
      - Supporting QoS, security, and robust wireless communication in dense environments

      **Related Functions:**

      - Frame control and addressing schemes
      - Sequence control to maintain packet order
      - Power management signaling to optimize device battery use
      - Error detection and recovery mechanisms using CRC and retransmissions

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         **Explore the details of 802.11an MAC Functions:**

         * :ref:`Learnings in this section <mac_functions_step1>`

         * :ref:`Terminology <mac_functions_step2>`

         * :ref:`Version Info <mac_functions_step3>`

         * :ref:`mac_functions Basic Setup on Ubuntu using IPv4 <mac_functions_step18>`

         * :ref:`Reference links <mac_functions_step17>`

      .. button-link:: ./802_11an/mac_functions.html
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   .. tab-item:: 802.11an MAC Timings

      **Standard:** IEEE 802.11an (2007)

      **Main Features:**

      - Defines timing parameters for frame transmission and acknowledgments over 40 MHz channels
      - Includes Interframe Spaces (SIFS, DIFS, PIFS, AIFS) to coordinate medium access
      - Specifies slot times and contention window sizes for CSMA/CA backoff in 5 GHz band
      - Ensures collision avoidance and fair access in high-throughput WLANs
      - Manages retransmission timing and acknowledgment intervals
      - Synchronizes MAC and PHY layers for efficient communication with wider channels

      **Use Cases:**

      - Coordinating transmission timing in 5 GHz WLANs using 40 MHz channels
      - Minimizing collisions and optimizing network throughput
      - Supporting QoS through prioritized timing and access control

      **Related Timing Parameters:**

      - Short Interframe Space (SIFS)
      - Distributed Interframe Space (DIFS)
      - Arbitration Interframe Space (AIFS)
      - Slot time and backoff timers

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         **Explore the details of 802.11an MAC Timings:**

         * :ref:`Learnings in this section <mac_timings_step1>`

         * :ref:`Terminology <mac_timings_step2>`

         * :ref:`Version Info <mac_timings_step3>`

         * :ref:`mac_timings Basic Setup on Ubuntu using IPv4 <mac_timings_step18>`

         * :ref:`Reference links <mac_timings_step17>`

      .. button-link:: ./802_11an/mac_timings.html
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         Jump to "802.11an MAC Timings"


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   .. tab-item:: 802.11an Packet Formats

      **Standard:** IEEE 802.11an (2007)

      **Main Features:**

      - Defines the structure of MAC and PHY layer frames used in 802.11an
      - Includes Frame Control, Duration, Address fields, Sequence Control, and CRC
      - Supports data frames, management frames, and control frames
      - Uses OFDM symbols with 40 MHz channel width at the PHY layer for high-speed transmission
      - Frame formats support addressing, QoS, and security features
      - Allows fragmentation and reassembly for large packets

      **Use Cases:**

      - Structuring wireless packets for communication in 5 GHz WLANs with wider channels
      - Ensuring proper delivery, acknowledgment, and retransmission of data
      - Enabling interoperability between devices by standardized frame formats

      **Related Frame Types:**

      - Management frames (e.g., Beacon, Probe Request)
      - Control frames (e.g., ACK, RTS, CTS)
      - Data frames (with or without QoS)

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         **Explore the details of 802.11an Packet Formats:**

         * :ref:`Learnings in this section <packet_formats_step1>`

         * :ref:`Terminology <packet_formats_step2>`

         * :ref:`Version Info <packet_formats_step3>`

         * :ref:`packet_formats Basic Setup on Ubuntu using IPv4 <packet_formats_step18>`

         * :ref:`Reference links <packet_formats_step17>`

      .. button-link:: ./802_11an/packet_formats.html
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   .. tab-item:: 802.11an Power Saving Mechanisms

      **Standard:** IEEE 802.11an (2007)

      **Main Features:**

      - Supports Power Save Mode (PSM) to reduce energy consumption on client devices
      - Clients enter sleep state and wake periodically to receive buffered data
      - Access Point buffers frames for sleeping stations and signals buffered data in beacon frames
      - Uses Delivery Traffic Indication Message (DTIM) to inform clients about multicast/broadcast data
      - Enables efficient battery usage for mobile and portable Wi-Fi devices in 5 GHz band with 40 MHz channels
      - Works with MAC layer mechanisms to coordinate sleep and wake cycles effectively

      **Use Cases:**

      - Extending battery life of Wi-Fi enabled mobile devices operating in 5 GHz band
      - Reducing power consumption in IoT and embedded Wi-Fi devices
      - Balancing network performance with power efficiency in high-throughput WLANs

      **Related Mechanisms:**

      - Beacon frame scheduling
      - DTIM and TIM fields for power management
      - Client wake-up and sleep signaling

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         **Explore the details of 802.11an Power Saving mechanisms:**

         * :ref:`Learnings in this section <power_save_step1>`

         * :ref:`Terminology <power_save_step2>`

         * :ref:`Version Info <power_save_step3>`

         * :ref:`power_save Basic Setup on Ubuntu using IPv4 <power_save_step18>`

         * :ref:`Reference links <power_save_step17>`

      .. button-link:: ./802_11an/power_save.html
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   .. tab-item:: 802.11an Interoperability

      **Standard:** IEEE 802.11an (2007)

      **Main Features:**

      - Ensures compatibility between devices from different vendors operating in 5 GHz band with 40 MHz channels
      - Supports coexistence with other 802.11 standards through dual-band or multi-radio devices
      - Defines common frame formats, signaling, and channelization to enable seamless communication
      - Implements clear channel assessment (CCA) and CSMA/CA for medium access coordination
      - Uses standardized management and control frames for association, authentication, and roaming
      - Facilitates coexistence and reduces interference with other wireless technologies in overlapping frequency bands

      **Use Cases:**

      - Enabling multi-vendor Wi-Fi deployments in enterprise and consumer networks using 802.11an
      - Supporting seamless handoff and roaming in heterogeneous Wi-Fi environments
      - Allowing mixed 802.11 standard networks to operate efficiently without interference

      **Related Mechanisms:**

      - Management frame interoperability
      - Frequency band and channel coordination
      - Standardized PHY and MAC layer procedures

      .. panels::
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         **Explore the details of 802.11an Interoperability mechanisms:**

         * :ref:`Learnings in this section <interoperability_step1>`

         * :ref:`Terminology <interoperability_step2>`

         * :ref:`Version Info <interoperability_step3>`

         * :ref:`interoperability Basic Setup on Ubuntu using IPv4 <interoperability_step18>`

         * :ref:`Reference links <interoperability_step17>`

      .. button-link:: ./802_11an/interoperability.html
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   .. tab-item:: 802.11an Physical Rates

      **Standard:** IEEE 802.11an (2007)

      **Main Features:**

      - Supports multiple physical layer data rates from 6 Mbps up to 300 Mbps
      - Utilizes Orthogonal Frequency Division Multiplexing (OFDM) modulation with 40 MHz channels
      - Provides selectable data rates: 6, 9, 12, 18, 24, 36, 48, 54, 72, 96, 108, 120, 144, 150, 180, 216, 240, 270, and 300 Mbps depending on MCS
      - Adapts rates dynamically based on signal quality and channel conditions
      - Uses 40 MHz wide channels in the 5 GHz frequency band to increase throughput
      - Enables higher data throughput and improved spectral efficiency compared to 802.11a

      **Use Cases:**

      - High-speed wireless networking in enterprise and home environments with wider bandwidth
      - Multimedia streaming, high-definition video, and low-latency applications over Wi-Fi
      - Wireless backhaul, bridging, and high-throughput WLAN deployments

      **Related Concepts:**

      - Rate adaptation algorithms
      - Modulation and coding schemes (MCS)
      - Channel bonding and spectrum management

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         **Explore the details of 802.11an Physical Rates:**

         * :ref:`Learnings in this section <physical_rates_step1>`

         * :ref:`Terminology <physical_rates_step2>`

         * :ref:`Version Info <physical_rates_step3>`

         * :ref:`physical_rates Basic Setup on Ubuntu using IPv4 <physical_rates_step18>`

         * :ref:`Reference links <physical_rates_step17>`

      .. button-link:: ./802_11an/physical_rates.html
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         Jump to "802.11an Physical Rates"


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   .. tab-item:: 802.11an PPDU

      **Standard:** IEEE 802.11an (2007)

      **Main Features:**

      - Defines the Physical Protocol Data Unit (PPDU) structure for 802.11an
      - Includes a preamble for synchronization, channel estimation, and MIMO training
      - Contains SIGNAL and HT-SIG fields specifying data rate, length, and MIMO parameters
      - Payload carries the MAC frame encoded with OFDM modulation using 40 MHz channels
      - Supports multiple spatial streams with adaptive modulation and coding
      - Enables high-throughput and reliable wireless data transmission in 5 GHz band

      **Use Cases:**

      - Ensuring proper encapsulation of data for transmission over 802.11an PHY
      - Synchronization and channel estimation for MIMO communication
      - Facilitating robust, high-speed wireless communication with multiple antennas

      **Related Concepts:**

      - OFDM and MIMO symbol structures
      - Service field, tail bits, and training sequences
      - Channel coding, interleaving, and spatial stream mapping

      .. panels::
         :container: container pb-4
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         :card: What You Will Learn in This Section

         **Explore the details of 802.11an PPDU:**

         * :ref:`Learnings in this section <ppdu_step1>`

         * :ref:`Terminology <ppdu_step2>`

         * :ref:`Version Info <ppdu_step3>`

         * :ref:`ppdu Basic Setup on Ubuntu using IPv4 <ppdu_step18>`

         * :ref:`Reference links <ppdu_step17>`

      .. button-link:: ./802_11an/ppdu.html
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         Jump to "802.11an PPDU"