A presence server for determining presence of a mobile station in a mobile network, including structure and/or function to: receive a request for a presence indication that the mobile station is active; send a first query into the mobile network based on the request; receive a response to the first query; and, if the response indicates the mobile station is active then: provide the presence indication; if the response indicates the mobile station is not active then: send a second query into the mobile network for establishing a notification trigger; receive a second query response based on the notification trigger; the second query response including the presence indication and being based on short message service (“SMS”); and provide the presence indication based on the second query response.