Patent ID: 7933608

Claim:
A method for maintaining and delivering presence information regarding telecommunications network subscribers, the method comprising: at a presence gateway separate from a presence server: (a) deriving presence information for a first set of telecommunications network subscribers based on telecommunications signaling messages relating to communications to or from members of the first set of subscribers, the first set of subscribers including at least one subscriber who is not currently subscribed to in a presence database, wherein each of the telecommunications signaling messages is a signaling system number 7 (SS7) message; (b) determining whether presence status associated with a first subscriber in the first set of subscribers has changed based on the presence information derived for the first subscriber; (c) in response to determining that the presence status associated with the first subscriber has changed, determining whether the first subscriber is a subscribed-to presentity; (d) in response to determining that the first subscriber is a subscribed-to presentity, notifying a presence server of the change in presence status of the first subscriber; and (e) in response to determining that the first subscriber is not a subscribed-to presentity, caching presence information for the first subscriber at the presence gateway.