802.11aj – the one made for China’s mmWave

IEEE Std 802.11aj-2018, Amendment 3 to the 2016 revision, was all about adapting Wi-Fi to fit **China’s specific millimeter-wave regulations**. no "Task Group aj" mentioned, but the result was a custom-tailored update to **802.11ad**, making it work cleanly in **China’s 60 GHz and 45 GHz bands**. this one didn’t reinvent the tech – it repackaged it for a regional rollout.

while 802.11ad (WiGig) already brought high-speed short-range wireless to the global stage, 802.11aj added support for **Chinese mmWave spectrum**, which differed slightly in terms of allocation and allowed frequencies. specifically, this amendment enabled operation in **both the 60 GHz and 45 GHz bands** within China – frequencies not globally standardized but locally important.

the amendment introduced two capability sets: - **CDMG (China Directional Multi-Gigabit)**, mirroring the directional features of DMG from 11ad, - **CMMG (Chinese Millimeter-wave Multi-Gigabit)**, offering tailored performance for the unique band conditions in China.

these came with updated **capability elements** to signal support during negotiation, ensuring interoperability between compliant devices in Chinese networks. all the core concepts from 11ad – beamforming, short-range high throughput, directional links – stayed intact, just adapted to fit national spectrum rules.

802.11aj was officially integrated into the **802.11-2020** revision, adding regional flexibility to an already powerful millimeter-wave standard.

802.11aj didn’t change what Wi-Fi could do – it changed **where** it could do it. high-speed wireless, now optimized for China’s spectrum map.