Methods and messages for performing assignment and activation of voice
bearer channels for mobile stations (MSs) in an unlicensed mobile access
network (UMAN). URR (UMA radio resource) channel activation messages are
exchanged between an MS and a UMA network controller (UNC) operating in
the UMAN to assign a voice bearer channel to the MS and verify the
channel is available for uplink. The MS may access the UMAN via a
wireless access point (AP) that is communicatively coupled to the UNC via
an IP network. The URR channel activation messages are sent between the
MS and the UNC using an Up interface comprising a set of layered
protocols over an underlying IP transport.