Who called from 8015143029

Called my cell, left no message.

Called my cell just now, left no message

I receive a phone call a few times a month from this or a similar number. When I pick up that is dead air for around ten seconds then it hangs up.

Called me on my Verizon wireless line at 11AM EST.  I picked up the phone but did not speak.  The person or computer at the other end was silent and eventually ended the call.

I received a phone call from this at 10:25 AM. When I pick up that is silent for around ten seconds then it hangs up...

Interestingly, 2 minutes later I received a silent call from 203-580-3521.