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WiFi operates at 2.4GHz band with bandwidths of 20MHz and 40MHz. WiFI can
generate both co-channel interference and adjacent channel interference to the
2.4GHz wireless link of a drone. Even if there is not a WiFi router is available for a WiFi
device (for example, WiFi of a phone) to connect with, a WiFi device periodically
transmits beacon/probe signals. So, when you operate a drone in the field with 2.4GHz
wireless link, it is important to turn off WiFi modem/hotspot of a phone, or a laptop. If
WiFi relay of the video from the ground station is desired, it is recommended to use a
5.8GHz WiFi modem.
Interference by Bluetooth device
Bluetooth operates on 2.4GHz in frequency hopping mode. So a Bluetooth mouse,
Bluetooth joystick, or any Bluetooth device that is actively working and next to ground
station will interfere the reception of downlink video. Please avoid using Bluetooth
device when operate a drone with 2.4GHz wireless link.
Interference by wireless device in co-existence
Another wireless device that operates on bands close to 2.4GHz and the device is
placed close to the drone’s 2.4GHz wireless module can interfere the drone’s wireless
link. For example, some drones have both LTE link and point-2-point wireless link.
Particularly, the LTE operating on 2.3GHz band can be a problem. If the antenna of the
LTE module is placed close to the antenna of the 2.4GHz point-2-point wireless
module, the receiver of 2.4GHz module can be saturated by the LTE signal when it is
transmitting. Thus, the range/performance of the 2.4GHz module will be significantly
degraded.
Interference by HDMI
When HDMI source/cable is close the antenna of 2.4GHz wireless modem, the HDMI
source/video will interfere the 2.4GHz wireless signal (including WiFi).
https://h30434.www3.hp.com/t5/Notebooks-Archive-Read-Only/HDMI-interfering-with-
WiFi-connectivity/td-p/4535026
