Abstract: A method for setting up a conference call where the subscribers are not only concentrated in one area but also more widely dispersed. The method allows both groups of subscribers to be contacted for a conference call with individuals close to the point of origination of the conference call being connected to a shared channel call and any members further out being connected to the conference call using individual channels. Members who initially started with an individual channel can move closer to the point of origin and automatically join the shared channel. This is of particular use to the emergency services where they may need to co-ordinate members arriving at the scene or performing related actions further away from the scene of the emergency.

Abstract: A system and method for performing location dependent addressing is provided suitable for use in GSM-R systems. A quadtree is used to store jurisdiction information as a function of location, for example GPS location. When a call is received that contains location information, it is processed by looking up the jurisdiction using the quadtree, and by then establishing a connection to the appropriate destination.

Abstract: A method for setting up a conference call where the subscribers are not only concentrated in one area but also more widely dispersed. The method allows both groups of subscribers to be contacted for a conference call with individuals close to the point of origination of the conference call being connected to a shared channel call and any members further out being connected to the conference call using individual channels. Members who initially started with an individual channel can move closer to the point of origin and automatically join the shared channel. This is of particular use to the emergency services where they may need to co-ordinate members arriving at the scene or performing related actions further away from the scene of the emergency.