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. Separate wireless cells can be provided and the
system supports roaming of individual mobile users from one cell to
another whilst maintaining the required communication set-up by the
crosspoint processor.