What's "reviving"?

You need to equip Second Chance Pro. For the opportunity to purchase the Pro variant you need to equip Second Chance and complete these three challenges.

• Kills – Get 10 kills while in Second Chance.
• Revenge – While in Second Chance, kill the enemy who downed you 5 times.
• Headshot – Get 1 headshot kill while in Second Chance.

The ability of your team mates to revive you does not depend on their perk setup. Second Chance Pro will also let you stay "downed" for longer.

If you have Second Chance Pro, then when you go down and pull out your pistol, ANY OTHER PLAYER can come and 'revive' you. Basically, it's like Gears of War, where when you 'die' your team mate has to get to you and help you back up so you can continue fighting.

Keep in mind that once you unlock Second Chance Pro, you still have to buy the perk in order to use it!