I was surprised to learn about Zenith AeroTech which shared a booth with Zenith Firearms. They manufacture tethered aerial systems.
There are two models of tethered drones, the Quad-L can carry up to 8 lbs of payload while the Quad-L will carry a 20 lbs payload aloft. Flight duration is based upon power provided by the ground power unit which also serves as a conduit for the data being collected by the drone. Below you can see the controller.
Units and agencies can procure products seen at Warrior East by contacting ADS, Inc.