A packet radio network for communicating internet packet data to and/or from a mobile user equipment, payload data of each of the internet data packets containing a plurality of different types of data, the packet radio network having a core network part and a radio network part, the core network including a gateway support node operable to provide an interface for communicating the data packets between the packet radio network and an external packet data network, a serving support node operable to control communication of the data packets between the gateway support node and the user mobile equipment via the radio network part, the radio network part providing radio access bearers for communicating the data packets to and/or from the mobile user equipment, wherein the core network is operable in response to a Packet Data Protocol context activation request from the mobile user equipment to establish a communications channel for communicating the internet data packets containing the different types of data to and/or from the user equipment via the packet radio network, the Packet Data Protocol context activation request data including at least one of a field specifying one of a plurality of data formats for communicating the internet data packets from the user equipment via the core network, and a field specifying one of a plurality of data formats for communicating the internet data packets to the user equipment via the core network, the internet packet data formats specifying an amount of data in each of the different data types of the payload, the communications channel established by the core network, including a bearer for communicating the internet packet data established for the communications channel between the gateway support node and a radio network controller via the serving support node, and for each of the different data types a radio access bearer having a different set of quality of service parameters for communicating the data packet to and/or from the mobile user equipment, and the radio network part includes the radio network controller, and the serving support node is operable to generate a Radio Access Bearer Sub-flow Combination Indicator providing an indication of the number of different types of data in the payload and the number of symbols in each different data type, the sub-flow indicator being generated in accordance with the field specifying the data format for communicating the data packets in the Packet Data Protocol context activation request for the communications channel, to form a transport frame for each internet data packet by combining the payload data and the header of each internet data packet with the sub-flow indicator, the transport frame being used to communicate each internet data packet via the bearer established for the communications channel between the gateway support node and the radio network controller via the serving support node, the data packets being communicated between the radio network controller and the user equipment by detecting the sub-flow indicator, and in accordance with the sub-flow indicator arranging for the data from each of the different data fields to be communicated via a different one of the radio access bearer providing different quality of service parameters appropriate for the different data type.