Arena is an active protection system (APS) developed at Russia's Kolomna-based Engineering Design Bureau for the purpose of protecting armoured fighting vehicles from destruction by light anti-tank weapons, anti-tank guided missiles (ATGM), and flyover top attack missiles. It uses a Doppler radar to detect incoming warheads. Upon detection, a defensive rocket is fired that detonates near the inbound threat, destroying it before it hits the vehicle.

An active protection system (APS) is a system designed to actively prevent certain anti-tank weapons from destroying a vehicle.