Abstract
In some countries, unlicensed spectrum used by WiFi networks is shared with radar systems. WiFi networks that operate in such bands employ radar detection and avoidance. A WiFi transceiver spends a certain channel sojourn (dwell) time scanning a channel prior to starting communication on it. A full scan takes about seven seconds, a user-perceptible delay.
This disclosure describes techniques to reduce scan time by leveraging radar detection procedures that have already been completed by nearby access points. If a nearby access point has recently transmitted a frame or emits a wide-band transmission, it is an indication that the nearby access point has confirmed that the channel is clear of radar. Therefore, a device that is about to initiate a full scan can abbreviate its scan duration substantially. With implementation of the techniques of this disclosure, scan times drop from seven seconds to under two seconds.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Lee, Jiwoong, "Fast WiFi scanning", Technical Disclosure Commons, (December 19, 2018)
https://www.tdcommons.org/dpubs_series/1788