Thus, the signallist names shown on figure show which protocols each entity speak with each other. To make the specification possible to overcome, only signals relevant to Mobile Station Location has been included in the specification. Each of the interfaces between the entities has been named. These names are shown in small letters at each signalroute. As far as possible the names are consistent with the interface names used in GSM specifications.
Figure shows the definition of each of the signallist.
Call setup signalling As already mentioned, only the signalling relevant to MSL has been included in the specification. The setup of the radio interface and authentication procedures as seen in has therefore been let out. A tone signalling in the MS indicates that the phone is ringing in the other end. When this message arrives at the MS, the connection is established and the user at the MS can talk to the operator at the emergency call centre. MSL signalling In order to perform Mobile Station Location, a number of other messages are exchanged in the MSC in figure .