802.11h - Basics ==================== .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is IEEE 802.11h?** IEEE 802.11h is an amendment to the IEEE 802.11 standard aimed at improving spectrum and transmit power management in the 5 GHz band to avoid interference with radar systems. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Why was IEEE 802.11h developed?** It was developed to meet regulatory requirements in Europe and other regions, primarily to avoid interference with radar systems operating in the 5 GHz band. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What key features does 802.11h introduce?** It introduces Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) to minimize interference with other users of the spectrum. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is Dynamic Frequency Selection (DFS)?** DFS is a mechanism that detects radar signals and switches the Wi-Fi device to a different channel to avoid interference. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is Transmit Power Control (TPC)?** TPC adjusts the transmit power of Wi-Fi devices to the minimum necessary to maintain communication, reducing interference with other systems. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **In which frequency band does 802.11h operate?** 802.11h operates primarily in the 5 GHz frequency band. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What regulatory issue does 802.11h address?** It addresses regulatory requirements for coexistence with radar and satellite systems in the 5 GHz spectrum. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does DFS improve Wi-Fi performance?** By avoiding channels used by radar, DFS reduces interference, improving overall Wi-Fi network stability and throughput. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is 802.11h mandatory in all countries?** No, it is mandatory in regions where regulatory bodies require radar detection and avoidance, such as Europe. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11h affect channel selection?** It forces Wi-Fi devices to scan for radar signals before using a channel and to switch channels if radar is detected. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the difference between DFS and TPC?** DFS handles channel switching to avoid radar, while TPC manages the transmit power level to reduce interference. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11h improve security?** No, 802.11h is focused on spectrum management and interference mitigation, not on security enhancements. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11h impact Wi-Fi deployment?** It requires compliant devices to support DFS and TPC to operate legally in certain bands, influencing device design and network planning. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11h be used with other Wi-Fi amendments?** Yes, 802.11h can be combined with other amendments like 802.11a, 802.11g, and 802.11n to provide enhanced features. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What happens if radar is detected on a channel?** Devices must stop transmissions on that channel and switch to a different channel where no radar is detected. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11h increase network latency?** It can cause slight delays during channel switching, but generally, the impact on latency is minimal. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What types of devices benefit most from 802.11h?** Devices operating in the 5 GHz band, especially in regulatory domains that require radar coexistence, benefit most. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is user intervention needed for DFS and TPC?** No, these functions operate automatically within compliant devices. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **When was IEEE 802.11h ratified?** It was ratified in 2003 as an amendment to the original 802.11 standard. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11h contribute to overall Wi-Fi ecosystem?** By ensuring regulatory compliance and reducing interference, it enables more reliable and wider deployment of 5 GHz Wi-Fi networks. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :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>` .. _802_11h_step1: .. tab-set:: .. tab-item:: Learnings in this section * In this section, you are going to learn .. _802_11h_step2: .. tab-set:: .. tab-item:: Terminology * Terminology .. _802_11h_step3: .. tab-set:: .. tab-item:: Version Info * Version Info .. _802_11h_step4: .. tab-set:: .. tab-item:: 802.11h Version&RFC Details * rfc details .. _802_11h_step5: .. tab-set:: .. tab-item:: 802.11h Basic Setup on Ubuntu using IPv4 * setup .. _802_11h_step6: .. tab-set:: .. tab-item:: 802.11h Basic Setup on Ubuntu using IPv6 * setup .. _802_11h_step16: .. tab-set:: .. tab-item:: Reference links * Reference links