Is there any way for a mobile carrier to trace "unknown calls" (i.e., no number shows up, just "unknown")?

This is driving me insane; someone keeps calling from an “unknown” number (no # shows up so I can’t do the reverse number lookup that a million webpages can “teach” me to do) and I hear absolutely nothing on the other end, not even a click. I’m wondering if it’s just a spammer, but this is really getting beyond annoying at this point. Would my cell phone carrier have any ability to trace this? Thanks.