In addition to sensor-based collision avoidance you would probably want some means of communication between the drones so they can choose non-colliding flight paths in advance.
In the altitude these drones will be flying most of the regular traffic probably is composed of helicopters. For those Amazon could easily provide some means of requesting a temporary drone no-flight zone.
In the altitude these drones will be flying most of the regular traffic probably is composed of helicopters. For those Amazon could easily provide some means of requesting a temporary drone no-flight zone.