User plane QoS management functions maintain the signalling and user data traffic within certain limits, defined by specific QoS attributes. UMTS bearer services with different QoS attribute values shall be supported by the QoS management functions. These functions ensure the provision of the QoS negotiated for a UMTS bearer service. Mapping function provides each data unit with the specific marking required to receive the intended QoS at the transfer by a bearer service. Classification function assigns data units to the established services of a MT according to the related QoS attributes if the MT has multiple UMTS bearer services established. The appropriate UMTS bearer service is derived from the data unit header or from traffic characteristics of the data. Resource Manager distributes the available resources between all services sharing the same resource. The resource manager distributes the resources according to the required QoS. Example means for resource management are scheduling, bandwidth management and power control for the radio bearer. Traffic conditioner provides conformance between the negotiated QoS for a service and the data unit traffic. Traffic conditioning is performed by policing or by traffic shaping. The policing function compares the data unit traffic with the related QoS attributes. Data units not matching the relevant attributes will be dropped or marked as not matching, for preferential dropping in case of congestion. The traffic shaper forms the data unit traffic according to the QoS of the service. The reference algorithm for traffic conditioning is described in Annex B. This reference algorithm should not be interpreted as a required implementation algorithm.