Knowledge of Wi-Fi standards

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I was working on openwrt some time ago, and I am interested in the wifi speed and mode. I am also a person with a strong thirst for knowledge. All of them are here to learn and make progress together under the popularization of science. Please forgive me if there are any mistakes.

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Wi-Fi

Wireless Local Area Network Based on IEEE 802.11 Standard

Wi-Fi (pronounced: /ˈwaɪfaɪ/ [[1]]( https://zh.m.wikipedia.org/wiki/Wi-Fi#cite_note-1) [[2]]( https://zh.m .wikipedia.org/wiki/Wi-Fi#cite_note-2) [[3]]( https://zh.m.wikipedia.org/wiki/Wi-Fi#cite_note-3) ), also known as “Wireless Hotspot ” or “Wireless Network”, is a trademark of the Wi-Fi Alliance, a wireless local area network technology based on the IEEE 802.11 standard. “Wi-Fi” is often written as “WiFi” or “Wifi,” but these spellings are not endorsed by the Wi-Fi Alliance.

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Wi-Fi products are rigorously tested by an independent authorized test laboratory of the Wi-Fi Alliance. After the products successfully pass the test, manufacturers or sellers are authorized to use the Wi-Fi logo, Wi-Fi CERTIFIED logo and related trademarks, Wi-Fi The Alliance uses the term “Wi-Fi CERTIFIED” to refer to such certified products. Certification means that the product is interoperable with other Wi-Fi CERTIFIED devices operating in the same frequency band.

IEEE 802.11

Media Access Control and Physical Layer Specification Set 请输入图片描述

IEEE 802.11 is a wireless local area network working group [1] under the IEEE 802 Standards Committee (IEEE 802 LAN/MAN Standards Committee), and also refers to the wireless local area network standards formulated by this organization.

Typically used in conjunction with IEEE 802.2, this protocol is designed for seamless interoperability with Ethernet, and is often used to carry IP traffic.

While the IEEE 802.11 specification lists the channels that may be used, the allowed use of the radio spectrum varies widely by regulatory domain.

Overview

The IEEE 802.11 standard defines a media access control (MAC) and several physical layer (PHY) specifications to provide wireless connectivity for fixed, portable, and transportable terminals (STAs) within a local area, and the standard also provides a standardized approach for regulators , to manage one or more frequency bands for LAN communication [[2]]( https://zh.m.wikipedia.org/wiki/IEEE_802.11#cite_note-2) .

Wi-Fi standard

已发布标准

The picture above is a table of published standards, including non-main standards. Below, we will list the main standards.

常见标准

The above picture can basically be regarded as a brief history of the development of the Wi-Fi standard

Wi-Fi Generation Names

Wi-Fi is based on IEEE 802.11. The Wi-Fi Alliance launched the “Generational Wi-Fi” marketing project in 2018. Based on the main Wi-Fi technology (PHY) version, it introduced “Wi-Fi” which is easier for consumers to understand. Wi-Fi generation names” in the format “Wi-Fi” followed by an integer, and encourages adoption of generation names as industry terms. Generation names do not affect previous certification program names, and for previous certification programs (such as Wi-Fi CERTIFIED ac or earlier), continue to use the original certification program name. The Wi-Fi Alliance did not assign new names to Wi-Fi generations prior to Wi-Fi 4.

  • The first generation is based on the original IEEE 802.11 standard, the working frequency band is 2.4GHz, and the maximum rate is half-duplex 2 Mbit/s.
  • The second generation is based on IEEE 802.11b, the working frequency band is 2.4GHz, the maximum rate is 11 Mbit/s half-duplex, and the certification project is “Wi-Fi CERTIFIED b”.
  • The third generation is based on IEEE 802.11a, the working frequency band is 5GHz, the maximum rate is 54 Mbit/s, and the certification project is “Wi-Fi CERTIFIED a”. Based on IEEE_802.11g, 2.4GHz working frequency band, the highest rate half-duplex 54 Mbit/s, the certification project is “Wi-Fi CERTIFIED g”.
  • The fourth generation, based on IEEE 802.11n, the generation name is “Wi-Fi 4”, the channel width is 20MHz, 40MHz, the working frequency band is 2.4GHz and 5GHz, the maximum 4 spatial streams, the maximum subcarrier modulation 64-QAM, the maximum The rate is half-duplex 600 Mbit/s, and the certification project is “Wi-Fi CERTIFIED n”.
  • The fifth generation, based on IEEE 802.11ac, the generation name is “Wi-Fi 5”, the channel width is 20MHz, 40MHz, 80MHz, 80+ 80MHz, 160MHz, the working frequency band is 5GHz, the maximum 8 spatial streams, the maximum subcarrier modulation 256-QAM, the highest rate is 6.9 Gbit/s half-duplex, and the certification project is “Wi-Fi CERTIFIED ac”.
  • The sixth generation, based on IEEE 802.11ax, the generation name is “Wi-Fi 6”, the channel width is 20MHz, 40MHz, 80MHz, 80+ 80MHz, 160MHz, the working frequency band is 2.4GHz and 5GHz, the maximum 8 spatial streams, the maximum Subcarrier modulation 1024-QAM, the highest rate half duplex 269.6 Gbit/s, the certification project is “Wi-Fi CERTIFIED 6”.
WiFi standard The internet
WiFi 1 802.11b
WiFi 2 802.11a
WiFi 3 802.11g
WiFi 4 802.11n
WiFi 5 802.11ac
WIFI 6 802.11ax

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