Start with simultaneous activity
Write down which activities must send data at the same time during a typical busy period. Separate optional tasks, such as a backup that can be rescheduled, from tasks that must remain usable, such as a work call or a camera upload. Count active uses rather than every device in the home. A device that is idle does not create the same planning question as a device actively sending video or files. This inventory is a planning aid, not a measurement of the connection.