Abstract: A digital wireless intercom system provides voice communications between selected mobile user stations via allocated radio channels. All communications flow via channels between the mobile stations and the base station. The base station includes a crosspoint processor for setting up desired communication links between users. A data store contains data identifying the preferences of each user, including the other users with whom communication links are to be set up. On receipt of a user ID from a mobile station, a correlator in the base station correlates the particular user with the channel being used by the mobile station of the user, so that the crosspoint processor can identify the channels in use for setting up the required communication links. The correlator dynamically updates the channel allocations as channels used by any particular user change. In this way, the crosspoint processor seamlessly follows channel changes, maintaining the required communication links with particular users.