In MAG you get lots of signals and there's a howling siren to warn all forces playing that an area is secured, as a barrage of helicopters will rush in allowing your squad and team players to respawn in those helicopters before pushing forward so taking them out during an area takeover is anti-productive. 

GUIDES: MAG Walkthrough PS3, MAG Strategy Help Walkthrough, MAG FAQ Handbook

Further investigation of the battlefield and maps included in MAG reveal lots of desert and mountainous regions, tank battles, and of course the must have communication with teammates. During a battle good communication with both your location, what's going on and what they might need to overcome is always the best approach no matter what the objective.