A Home Location Server (HLS) and method of processing an incoming real-time call to a Mobile Station (MS) in a hybrid radio telecommunications network having both second generation (2G) and third generation (3G) service nodes. When a request for location information for the called MS is received in the HLS from an interrogating switch where the incoming call originated, the HLS determines whether the called MS is located in a 2G Mobile Switching Center (MSC), or a 3G Call State Control Function (CSCF). If neither, the HLS concludes that the called MS is located in an Serving General Packet Radio Service (GPRS) Support Node (SGSN). A 3G flag, which is set in the subscriber profile when the MS registers with a 3G SGSN, is checked to determine whether the SGSN is a 2G SGSN or a 3G SGSN. If the SGSN is a 2G SGSN, the HLS informs the interrogating switch that the MS is not available for the real-time call. If the SGSN is a 3G SGSN, the HLS orders the SGSN to page the MS and determine whether the MS accepts the incoming call.