Use Do not disturb mode to reject calls, and silence audible alerts and notifications, but still keep a data connection available.
Go to Settings, and then tap
Sound & notification.
Tap the Do not disturb
On/Off switch to turn it on and off.
Do not disturb to set when you want Do not disturb to turn off, or to allow the
Clock app alarm and timer sounds to play when Do not disturb is on.
The Do not disturb icon
will appear in the notifications area of the status bar. Even when Do not disturb mode is on, you'll still see notification icons in the status bar to alert you of missed calls, new messages, calendar events, alarms, and other notifications.