Level 15

Total Experience Required 27,780

Level 100 progress: 0.41%

This is roughly the same as:

Killing 47 people in Warzone, or...
Killing 48 people in Execution, or...
Killing 40 people in Wingman, or...
Scoring 9,922 points in Guardian, or...
Scoring 30,196 points in Annex, or...
Scoring 18,277 points in Submission.

Horde (TU4)

Completing 70 waves on Casual, or...
Completing 47 waves on Normal, or...
Completing 35 waves on Hardcore, or...
Completing 28 waves on Insane.

Or a combination of the above. Have fun!