Silent Calls.

I have been receiving "silent" calls at different hours from an individual, (281-738-3845), who reminds of a previous caller from a name listed as "Back and Knee" (512-643-0189), who was also calling me from Texas.
I have never had communication with either of these two callers and have no idea why they are calling me in California for.  I would appreciate any help in this regard.
Thank you.