802.11h - Spectrum and Power Management =========================================== .. toctree:: :maxdepth: 1 :hidden: :includehidden: 802_11h/802_11h 802_11h/mac_functions 802_11h/mac_timings 802_11h/packet_formats 802_11h/power_save 802_11h/interoperability 802_11h/physical_rates 802_11h/ppdu 802_11h/channels 802_11h/PHYs **IEEE 802.11h** enhances 5 GHz Wi-Fi with Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) to avoid interference and comply with regulatory requirements. .. list-table:: :widths: 20 60 20 :header-rows: 1 * - Category - Description - Use Case * - MAC Functions - Adds Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) to the MAC layer for improved spectrum management and interference avoidance. - Enables regulatory compliance and efficient use of spectrum in 5 GHz band deployments. * - MAC Timings - Defines timing mechanisms to support DFS channel switching and TPC adjustments without disrupting ongoing transmissions. - Ensures seamless operation while avoiding interference with radar systems and other critical services. * - Packet Formats - Introduces new management frames and information elements to convey DFS and TPC parameters between access points and clients. - Facilitates coordination for dynamic channel selection and power adjustments. * - Power Save - Integrates with legacy power save modes while managing power levels dynamically via TPC for energy-efficient transmissions. - Balances power savings with regulatory power limits and interference mitigation. * - Interoperability - Ensures coexistence with legacy 802.11a/b/g devices and compliance with regional regulatory requirements through DFS and TPC. - Enables smooth network operation in mixed device and regulatory environments. * - Physical Rates - Operates primarily in the 5 GHz band with data rates and modulation schemes similar to 802.11a but enhanced with spectrum management. - Supports reliable medium throughput with minimized interference. * - PPDU - Utilizes OFDM-based PPDU formats with added signaling for DFS and TPC compliance. - Supports robust physical layer communication with dynamic spectrum adaptation. * - Channels - Implements DFS to detect radar signals and dynamically switch channels to avoid interference. - Employs TPC to adjust transmit power within regulatory limits on 5 GHz channels. * - PHY Overview - Based on OFDM physical layer similar to 802.11a, augmented with spectrum sensing and power control features. - Enables efficient and regulatory-compliant use of 5 GHz spectrum in Wi-Fi networks. .. tab-set:: .. tab-item:: 802.11h Basics **Standard:** IEEE 802.11h (2003) **Main Features:** - Introduces Dynamic Frequency Selection (DFS) to avoid radar interference - Implements Transmit Power Control (TPC) for efficient power usage - Operates primarily in the 5 GHz band complying with regional regulations - Enhances coexistence with radar and other priority users in the spectrum - Improves network reliability by automatic channel switching - Supports regulatory compliance for global deployments **Use Cases:** - Wireless LAN deployments in regions with strict spectrum regulations - Environments where radar coexistence is mandatory (e.g., military, weather radar zones) - High-performance Wi-Fi in 5 GHz band with minimal interference - Enterprise and service provider networks requiring dynamic spectrum management **Related Concepts:** - Dynamic Frequency Selection (DFS) - Transmit Power Control (TPC) - Spectrum sensing and interference avoidance - Regulatory compliance mechanisms - Coexistence with radar systems and legacy Wi-Fi devices .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the foundational concepts of 802.11h:** * :ref:`Learnings in this section <802_11h_step1>` * :ref:`Terminology <802_11h_step2>` * :ref:`Version Info <802_11h_step3>` * :ref:`802_11h Version&IEEE Details <802_11h_step4>` * :ref:`802_11h Basic Setup on Ubuntu using IPv4 <802_11h_step5>` * :ref:`802_11h Basic Setup on Ubuntu using IPv6 <802_11h_step6>` * :ref:`Reference links <802_11h_step16>` .. button-link:: ./802_11h/802_11h.html :color: primary :shadow: :expand: Jump to "802.11h Basics" .. tab-set:: .. tab-item:: 802.11h MAC Functions **Standard:** IEEE 802.11h (2003) **Main Features:** - Implements mechanisms for Dynamic Frequency Selection (DFS) at MAC layer - Supports Transmit Power Control (TPC) commands to manage power levels dynamically - Integrates channel switching procedures triggered by radar detection or regulatory requirements - Coordinates with PHY layer to ensure interference avoidance and compliance - Handles MAC timing adjustments to support DFS and TPC operations - Ensures interoperability with legacy 802.11 devices while enforcing spectrum regulations **Use Cases:** - Managing radar coexistence and interference avoidance in 5 GHz Wi-Fi deployments - Regulatory compliance in regions requiring spectrum management - Enterprise and outdoor WLANs operating in DFS-enabled channels - Enabling dynamic channel selection to maintain network performance and stability **Related Functions:** - DFS state machines and channel availability checks - Power control message exchanges between stations and access points - MAC timers adapted for radar detection and channel switch announcements - Interworking with legacy 802.11 MAC functions for smooth operation .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11h MAC Functions:** * :ref:`Reference links <802_11h_mac_functions_step17>` .. button-link:: ./802_11h/mac_functions.html :color: primary :shadow: :expand: Jump to "802.11h MAC Functions" .. tab-set:: .. tab-item:: 802.11h MAC Timings **Standard:** IEEE 802.11h (2003) **Main Features:** - Adds Dynamic Frequency Selection (DFS) to avoid interference with radar systems - Implements Transmit Power Control (TPC) to minimize interference and conserve power - Integrates regulatory compliance mechanisms for 5 GHz spectrum usage - Builds on legacy MAC timing with additional rules for DFS and TPC - Supports timing coordination for spectrum management and channel switching - Ensures coexistence with radar and other priority users in shared bands **Use Cases:** - Meeting regulatory requirements in 5 GHz bands for Europe and other regions - Avoiding interference with radar and weather systems in shared frequencies - Enhancing wireless network reliability and legal compliance **Related Timing Parameters:** - Channel Availability Check Time (CAC) - Dynamic Frequency Selection (DFS) timing intervals - Transmit Power Control (TPC) update intervals - Standard Interframe Space (SIFS), Distributed Interframe Space (DIFS) .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11h MAC Timings:** * :ref:`Reference links ` .. button-link:: ./802_11h/mac_timings.html :color: primary :shadow: :expand: Jump to "802.11h MAC Timings" .. tab-set:: .. tab-item:: 802.11h Packet Formats **Standard:** IEEE 802.11h (2003) **Main Features:** - Defines MAC and PHY frame structures adapted for DFS and TPC features - Includes additional fields and management frames for Dynamic Frequency Selection - Supports regulatory compliance signaling and channel switch announcements - Enables coexistence with radar and other priority users via specialized frame formats - Incorporates power control information within frame headers for Transmit Power Control - Maintains backward compatibility with legacy 802.11 protocols **Use Cases:** - Ensuring regulatory compliance in 5 GHz spectrum with radar avoidance - Efficient signaling of channel availability and power adjustments - Reliable communication in dynamic frequency environments **Related Frame Types:** - Channel Switch Announcement (CSA) frames - Measurement and radar detection frames - Power control-enabled data and management frames .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11h Packet Formats:** * :ref:`Reference links ` .. button-link:: ./802_11h/packet_formats.html :color: primary :shadow: :expand: Jump to "802.11h Packet Formats" .. tab-set:: .. tab-item:: 802.11h Power Saving Mechanisms **Standard:** IEEE 802.11h (2003) **Main Features:** - Incorporates power control strategies via Transmit Power Control (TPC) - Helps reduce interference and conserve battery power through adaptive power adjustments - Works alongside DFS to optimize channel usage and minimize transmission disruptions - Supports legacy power saving modes enhanced with regulatory-aware transmission limits - Enables network devices to comply with regional power restrictions while maintaining connectivity - Facilitates improved battery life for client devices in 5 GHz networks **Use Cases:** - Power-aware operation in regulatory-controlled frequency bands - Battery-efficient wireless operation for portable devices in DFS-enabled networks - Minimizing interference through dynamic power adjustments **Related Mechanisms:** - Transmit Power Control (TPC) algorithms and updates - Coordination with DFS timing for safe transmissions - Legacy Power Save Mode (PSM) compatibility .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11h Power Saving mechanisms:** * :ref:`Reference links ` .. button-link:: ./802_11h/power_save.html :color: primary :shadow: :expand: Jump to "802.11h Power Saving" .. tab-set:: .. tab-item:: 802.11h Interoperability **Standard:** IEEE 802.11h (2003) **Main Features:** - Ensures compatibility with legacy 802.11 devices while enforcing DFS and TPC requirements - Supports coexistence with radar systems and priority users in shared 5 GHz bands - Implements mechanisms for channel switch announcements to facilitate smooth transitions - Works with legacy power control and frequency selection protocols for seamless integration - Enables dynamic frequency adjustments without disrupting legacy communication - Supports regulatory compliance while maintaining interoperability with older Wi-Fi standards **Use Cases:** - Deploying 802.11h in mixed environments with legacy 802.11a/b/g devices - Ensuring smooth operation in regulatory-controlled 5 GHz bands with radar presence - Supporting gradual migration to DFS and TPC-enabled networks without service disruption **Related Mechanisms:** - Channel Switch Announcement (CSA) for coordination across devices - Transmit Power Control (TPC) coexistence with legacy power save modes - DFS detection and mitigation signaling compatible with non-802.11h devices .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11h Interoperability mechanisms:** * :ref:`Reference links ` .. button-link:: ./802_11h/interoperability.html :color: primary :shadow: :expand: Jump to "802.11h Interoperability" .. tab-set:: .. tab-item:: 802.11h Physical Rates **Standard:** IEEE 802.11h (2003) **Main Features:** - Defines physical layer data rates compliant with regulatory requirements in 5 GHz bands - Supports rate adaptation with Transmit Power Control (TPC) and Dynamic Frequency Selection (DFS) - Ensures operation without interfering with radar and other priority users - Uses OFDM modulation consistent with 802.11a PHY while enforcing power and channel restrictions - Enables dynamic adjustment of rates based on environment and regulatory constraints - Maintains reliable wireless performance within regional transmission limits **Use Cases:** - Compliant high-rate transmissions in DFS-enabled 5 GHz frequency bands - Supporting roaming and operation in regulatory-controlled wireless environments - Enterprise and public Wi-Fi deployments adhering to regional physical rate rules **Related Concepts:** - Transmit Power Control (TPC) mechanisms affecting physical rates - DFS-triggered rate adaptation and channel management - OFDM physical modulation under regulatory constraints .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11h Physical Rates:** * :ref:`Physical Rates in 802.11h ` * :ref:`Reference links ` .. button-link:: ./802_11h/physical_rates.html :color: primary :shadow: :expand: Jump to "802.11h Physical Rates" .. tab-set:: .. tab-item:: 802.11h PPDU **Standard:** IEEE 802.11h (2003) **Main Features:** - Defines PPDU structure aligned with 802.11a PHY using DFS and TPC compliance - Supports OFDM modulation in the 5 GHz band with regulatory adaptations - Integrates mechanisms for Transmit Power Control (TPC) within PHY layer signaling - Incorporates channel availability checks and dynamic frequency selection (DFS) signaling - Maintains compatibility with legacy 802.11a PPDUs while enforcing 802.11h constraints - Enables reliable and compliant wireless transmission in regulated frequency bands **Use Cases:** - Ensuring lawful physical layer transmissions in DFS-enabled 5 GHz bands - Supporting regulatory compliance for power and frequency in PPDU format - Reliable communications in radar-sensitive environments **Related Concepts:** - OFDM PHY format with 802.11h adaptations - TPC and DFS signaling embedded in PHY - PPDU timing and power control coordination .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11h PPDU:** * :ref:`Reference links ` .. button-link:: ./802_11h/ppdu.html :color: primary :shadow: :expand: Jump to "802.11h PPDU" .. tab-set:: .. tab-item:: 802.11h Channels **Standard:** IEEE 802.11h (2003) **Main Features:** - Manages channel usage dynamically in the 5 GHz band to comply with regional regulations - Implements Dynamic Frequency Selection (DFS) to detect and avoid radar interference - Supports Transmit Power Control (TPC) to limit output power according to regulatory limits - Uses Channel Availability Check (CAC) timers before switching to a new channel - Communicates channel changes via Channel Switch Announcement (CSA) frames to clients - Ensures coexistence with radar systems and priority users in shared frequency bands **Use Cases:** - Enabling legal and efficient operation in 5 GHz Wi-Fi bands with radar coexistence - Dynamically selecting channels to avoid interference and comply with regulations - Facilitating seamless channel switching in enterprise and public Wi-Fi networks **Related Concepts:** - Dynamic Frequency Selection (DFS) mechanisms and timing - Channel Availability Check (CAC) intervals - Transmit Power Control (TPC) algorithms and limits - Channel Switch Announcement (CSA) management frames .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11h Channels:** * :ref:`List of channels ` * :ref:`List of channel widths ` * :ref:`List of Bands ` * :ref:`Reference links ` .. button-link:: ./802_11h/channels.html :color: primary :shadow: :expand: Jump to "802.11h Channels" .. tab-set:: .. tab-item:: 802.11h PHY **Standard:** IEEE 802.11h (2003) **Main Features:** - Implements OFDM PHY compliant with DFS and TPC regulations in 5 GHz bands - Supports dynamic frequency selection to avoid interference with radar systems - Enables transmit power control for regulatory compliance and interference mitigation - Operates exclusively in the 5 GHz band with strict spectrum usage rules - Uses 64 subcarrier OFDM modulation, similar to 802.11a PHY - Supports robust error correction with convolutional coding and interleaving - Ensures coexistence with other wireless systems through channel management **Use Cases:** - Regulatory-compliant wireless deployments in radar-sensitive 5 GHz bands - Maintaining reliable communications in dynamic spectrum environments - Enterprise and public Wi-Fi networks adhering to regional regulations **Related Concepts:** - Dynamic Frequency Selection (DFS) mechanisms - Transmit Power Control (TPC) in PHY layer - OFDM modulation with regulatory constraints .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11h PHY:** * :ref:`Reference links ` .. button-link:: ./802_11h/PHYs.html :color: primary :shadow: :expand: Jump to "802.11h PHY"