Abstract: Drawbacks of known methods of location determination are that the location can be determined only when the mobile station is setting up a call and during the call. The invention utilises that characteristic feature of mobile telephone systems that the location of the terminal is always known to the system with location area precision and that the geographical network topology is known to the network planning system. The tracing system includes three functional parts: a first part provides the mobile telephone system with the connection number of the traced terminal as an enquiry input, and in response to the input it receives information on where the subscriber's location area should be enquired for. The second functional part asks for the subscriber's location area and receives in response a location area code, which identifies the location area unambiguously.

Abstract: Procedure and system for optimizing the route of a telecommunication connection to be set up in a telecommunication system that includes a mobile switching center (MSC), a service switching point (SSP), a service control point (SCP), a gateway (GW), and a subscriber register (HLR). The service switching point is connected to the service control point and the gateway is connected to the service control point and to the subscriber register. The telecommunication connection to be set up is directed via the service switching point to the service control point. A database query is sent from the service control point, via the gateway, to the subscriber register. In response, the subscriber register returns routing information, on the basis of which an optimal route to the mobile switching center under which the B-subscriber is currently located is determined.