Main article: Multi-user MIMO. Recently, results of research on multi-user MIMO technology have been emerging. While full multi-user MIMO (or network MIMO) can have a higher potential, practically, the research on (partial) multi-user MIMO (or multi-user and multi-antenna MIMO) technology is more active.
There are two ways to decline a call on the iPhone. 1  By pressing the Sleep/Wake button. 2  By tapping the 'Decline' button onscreen (appears only when the phone is unlocked, as you've mentioned)
Call Rejection. Use Call Rejection when you want to block specific phone numbers. To do this, you create a list of the phone numbers that you want to reject. Then, anyone calling from a number on your list can't get through.