Blum, N.N.BlumMagedanz, T.T.Magedanz2022-03-102022-03-102005https://publica.fraunhofer.de/handle/publica/34988910.1109/ISM.2005.932-s2.0-33846324047en004PTT + IMS = PTM - towards community/presence-based IMS multimedia servicesconference paper