Method and system for avoiding mid-air collisions and traffic control

A decentralized density control (DDC) airborne unit for placing onboard an aerial platform, the DDC airborne unit comprising:

• a processor configured, based on current location of the aerial platform obtained from one or a plurality of navigational or positioning sensors, and based on current locations of other aerial platforms, on speed and heading of the airborne unit, based on at least one air traffic rule relating to a predefined personal airspace of the aerial platform,
• to generate steering commands to one or more of other airborne units of said other airborne platforms with a lower priority level than a priority level of the aerial platform with the onboard airborne unit so as to reduce the number of the other aerial platforms in or about to enter the personal airspace of the aerial platform so as not to exceed the predetermined number of aerial platforms in a personal airspace, which is related to the aerial platform which according to an air traffic rule dictates that the personal airspace includes at any time no more than a predetermined number of aerial platforms, or
• to calculate an own evading maneuver and to cause the aerial platform to perform said own evading maneuver to reduce the number of aerial platforms in own personal airspace, in order to not exceed the predetermined number of aerial platforms in or about to enter the personal airspace.