10. An apparatus in a group manager of a central service node for enabling services or media in a communication network, comprising: a monitoring unit adapted to detect activities and conditions of communication devices in the network, a context collecting unit adapted to, for each of a plurality of entities, collect individual context data relating to the entity, the individual context data comprising a first data value corresponding to a first behavioral context parameter, and a second data value corresponding to a first environmental context parameter, wherein first behavioral context parameter is separate and distinct from the first environmental context parameter, a context vector unit adapted to, for each of the plurality of said entities, create an individual context vector for said entity from said collected individual context data related to said entity wherein each of said plurality of context vectors identifies a point in a logical, as opposed to a physical, N-dimensional space, where N is greater than or equal to two, the context vector unit further adapted to create a master context vector comprising a third data value corresponding to the first behavioral context parameter, and a fourth data value corresponding to the first environmental context parameter, wherein the master context vector identifies a centroid point in the logical N-dimensional space, a distance calculating unit adapted to determine, for each of the plurality of said individual context vectors, the distance between the centroid point and the point identified by said individual context vector, and a group defining unit adapted to define a group of correlated entities that are found to be correlated or similar with respect to one or more features or characteristics based on the collected individual context data by including an entity in the group in response to determining that the distance between the centroid point and the point identified by said individual context vector corresponding to said entity is less than a threshold.
10. An apparatus in a group manager of a central service node for enabling services or media in a communication network, comprising: a monitoring unit adapted to detect activities and conditions of communication devices in the network, a context collecting unit adapted to, for each of a plurality of entities, collect individual context data relating to the entity, the individual context data comprising a first data value corresponding to a first behavioral context parameter, and a second data value corresponding to a first environmental context parameter, wherein first behavioral context parameter is separate and distinct from the first environmental context parameter, a context vector unit adapted to, for each of the plurality of said entities, create an individual context vector for said entity from said collected individual context data related to said entity wherein each of said plurality of context vectors identifies a point in a logical, as opposed to a physical, N-dimensional space, where N is greater than or equal to two, the context vector unit further adapted to create a master context vector comprising a third data value corresponding to the first behavioral context parameter, and a fourth data value corresponding to the first environmental context parameter, wherein the master context vector identifies a centroid point in the logical N-dimensional space, a distance calculating unit adapted to determine, for each of the plurality of said individual context vectors, the distance between the centroid point and the point identified by said individual context vector, and a group defining unit adapted to define a group of correlated entities that are found to be correlated or similar with respect to one or more features or characteristics based on the collected individual context data by including an entity in the group in response to determining that the distance between the centroid point and the point identified by said individual context vector corresponding to said entity is less than a threshold. 13. The apparatus according to claim 10 , wherein updating the group includes changing the context parameters of relevance and/or the membership conditions.