One method for joining a meet-me conference call includes establishing a communication channel, in response to a request to join a conference call; receiving, over the channel, information as to whether the conference call is still ongoing; and if the conference call is no longer ongoing, giving notification...http://www.google.fr/patents/US8024402?utm_source=gb-gplus-shareBrevet US8024402 - Call optimization in meet-me conference calls
