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)
The party you are calling does not accept blocked calls. If you are calling from a blocked number, please hang up, pick up the receiver, press *87 and redial the phone number. When you do this, your name and number will appear for this call only. In many areas Anonymous Call Rejection comes with Caller ID.