I don't PvP much, but it's obvious that there is no such think as "threat" in PvP. How do tanks go about grabbing the attention of opposing players gunning for the objective or healers?
AOE taunt. It reduced the damage done by all enemies in range by 30% for a period of time.
You cannot MAKE them focus on you, but you can do your best to reduce the damage they do to people.
And also guard your healers.