I'm thinking the drone solution in the immediate future will be more drones. Absolutely loads of them saturating an area, be it tethered or auto land, charge, take off at designated charge stations. That way they'll always be x amount I'm the air. When they're destroyed, a new "order" is generated to replace to that area. They'll be connected like a MESH radio network to transmit silly long distance. All have thermal capabilities to identify enemy drones including fibre optic drones and designate them to be destroyed by hunter killer type drones that are auto launched.