A method for Radio Network Controller (RNC) initiated Radio Access Bearer (RAB) negotiation or renegotiation/reconfiguration in a communication system that includes a core network and user equipment coupled to an RNC in a Universal Terrestrial Radio Access Network. When the core network establishes a service (e.g. voice call, web surfing session) with the user equipment, a RAB is set up for that service. The RAB includes certain parameters that effect the quality of the service. As the RNC monitors radio conditions, it may determine that one or more of the RAB parameters need to be modified. The RNC will initiate a RAB renegotiation/reconfiguration procedure by sending a RAB Modification Request Message to the CN specifying that a modification to the RAB is needed and the manner is which the modification should be affected. The CN may send a RAB Assignment Request Message informing the RNC whether the modification is acceptable.