Four Patrol Base Kits (sand or olive) within 5 metres of where you stand, on foot. A kit is a heavy case (three toolkits' worth); dropped kits and carried kits both count. ACE interact on a kit on the ground gives Pick up Patrol Base Kit.

[PICTURE: four kits dropped together]

1. Drop the kits.
2. ACE self-interact → Establish Patrol Base. It only appears once enough kits are down and fewer than three bases exist.
3. Name it in the popup (it suggests "Patrol Base N") and Confirm.

The kits are used up; a SatCom mast goes up as the beacon, a marker in your side's colour goes on the map, and everyone is told "name: Patrol base established." A staging zone and a teleport point come with it where the mission supports them.

[PICTURE: the finished base: mast, marker on the map]

Within 3 metres of the mast: scroll menu → Unbuild Patrol Base (recover kits). The kits are laid back out in a ring.

Zeus can drop kits with Drop Patrol Base Kits.