Motivation:

Have you ever tried to get several busy people to participate in the same meeting?
After checking with several personal assistants and outlook calendars, emailing individuals for preferred meeting time… you realize you have to wait two weeks before you can find a suitable time for everyone...
Don’t you wish there was a service, which could automatically detect people’s availability, and when all attendants were available, launch a meeting request via wireline phone, mobile phone or computer, and initiate the conference?

The feature:

SIP Application Server can subscribe to a Presence Server, in order to receive automatic presence notification when all users are online. Then upon receiving this notification it will call each participant, will call a conference/media server and will connect all users to the bridge.

How this can be accomplished:

Figure 1 below illustrates how this can be accomplished.