UAV Communication
Wireless communication is mandatory for any kind of drone / UAV unless you want to fly those with long signal line attached between you and drone like flying a kite.
Even a super cheap toy drone as below use a wireless communication between the controller and the drone. Usually they would use analog communication in unlicensed band.

A little bit higher cost drone as shown below use wireless communication in most case with multiple communication link. Mainly using a link for drone control and another links to retrieve various data from drone (like video image). The communication technology between these links can be same or different. For example, they can use analog communication for drone control and digital communication (like WiFi) for data. Or they can use the same / similar communication for both. For example, analog communication for both controller and data, or digital communication (like WiFi) for both control and data.

One of the most complicated communication technology for UAV/drone would be something like military applicated as illustrated below. The numbered circle in the illustration indicates wireless link. In most case, in this case the radio link would be licensed or dedicated spectrum not open to public and the communication would be highly encrypted\

Source : Unmanned Aircraft Systems - A Lecture on UAS Basics by Unmanned Experts
YouTube
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- The Technology Behind....How The New DJI Spark Remote Control Works (Jun 2017)
- Wireless Communications with Unmanned Aerial Vehicles (Dec 2017)
- Wireless Communications with Unmanned Aerial Vehicles - Wireless @ Virginia Tech (Dec 2017)
- Drone Communication (Jan 2019)
- BEST DRONE RADIO FOR BEGINNERS - Frsky x9 lite review (Aug 2019)
- Beginner Series: Transmitter Explained - Drone Radio, Drone Controller, which to chose? (Mar 2020)
- Radio Knowledge for Drone Pilots - Part 1: Radio Theory (Feb 2021)
- Radio Knowledge for Drone Pilots - Part 2: When to Use a Radio (Feb 2021)
- Radio Knowledge for Drone Pilots - Part 3: Etiquette (Mar 2021)
- SmartAP AIRLink - The Most Advanced AI Drone Avionics (Apr 2021)
- IEEE VTS Webinar on AAM: Accessing from the Sky: UAV Communications for 5G & Beyond - IEEE VTS (2023)
Reference