A presence calculation method comprising receiving first presence subscription request for a composite service that comprises a service at the node and a plurality of discrete services at one or more child nodes, sending a second presence subscription request to one or more child nodes in response to the first subscription request, receiving one or more response messages that comprise a collection of presence state transition delays corresponding to the child nodes from the child nodes in response to the second subscription request, determining one or more communication delays between the node and the child nodes using the response messages, computing a presence state transition delay for the composite service using the collection of presence state transition delays and the communication delays; and determining a composite presence state using a mapping between the presence state transition delay for the composite service and the composite presence state.