2. The mobile face-to-face interaction monitoring device according to claim 1 , wherein the conversation group detector comprises: a voice detector for detecting sound signals, and an interactant manager for storing mobile device addresses and forming the conversation group when the mobile devices having the addresses are scanned.
2. The mobile face-to-face interaction monitoring device according to claim 1 , wherein the conversation group detector comprises: a voice detector for detecting sound signals, and an interactant manager for storing mobile device addresses and forming the conversation group when the mobile devices having the addresses are scanned. 3. The mobile face-to-face interaction monitoring device according to claim 2 , wherein the conversation group detector further comprises a subgroup detector for determining subgroup formation by analyzing overlapping speech pattern in the sound signals.