Call of Duty DMZ White Lotus "NIGHT OPERATION" IR Beacon #1 Location:

Find your way up the north tower, accessible from the ground via the elevator shaft. You slide up the cables you'll find there, in the heart of the ground floor of the construction site below the tower.

Once you arrive at the top of the elevator shaft cable, you're too high up. Walk down the stairs to the concrete platform level and find your way to the pillar facing the bridge in AlMazrah, at heading 285 (see video). You'll be prompted to plant the beacon with your interact key/button.