When I was growing up, the phone always rang on Christmas morning and it would be an Uncle or some other relative calling to see if we were up and wishing us Merry Christmas.
Also when I got married and started raising my own family, the phone would ring and we would know family was thinking of us.
My parents spent every Christmas with us, spending the night Christmas Eve but now they are both deceased so we really feel their absence.
But it's most important to enjoy the family that is with you and not dwell on the deceased loved ones for they surely would not want to cause grief on such joyous time.
So we focus on who is with us and not on who isn't with us.