What is the meaning of this white arrow kind of thing in minimap?

What is the meaning of this white arrow kind of thing in minimap?

Map: Zavod 311

Game mode: Obliteration

Solution 1:

This is showing that a friendly Man-Portable Active Protection System (MP-APS) is active and the white area is showing the "protected" area. If the white line is blinking it means it is offline/recharging.

For an overview of how the MPAPS works, see this Battlefield 4 wiki page, however, it is a support gadget that works very similar to active protection. It will destory any tank shells/TOW missiles/LAV cannon that is fired at it, and although it has a limited use range, when use effectively it can reduce the amount of damage friendly armor can take hugely.