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)
Calls from contacts or phone numbers added to the reject list are automatically ignored and the call is forwarded to voicemail. 1  The Call Block feature allows the user to prevent the device from responding to a call. 2  Call Block requires software version iOS7 or later. 3  From the Home screen, tap Phone (located in the lower-left).