Colour-aware rate/coverage-controlled DS/CDMA downlink transmission for DiffServ

To improve the quality-of-service (QoS) support over cellular DS/CDMA systems with IP transport, rate/coverage-controlled downlink transmission schemes that utilise the QoS information from the IP layer of the differentiated services (DiffServ) architecture are proposed. The rate/coverage is controlled depending on the packet-drop precedence (packet colour) of the assured forwarding class in DiffServ and the traffic load at the base station. The out-of-profile packets are given less priority in the physical rate allocation or provided with less coverage compared with the in-profile packets. Simulations verify the advantages of the DiffServ-aware schemes and show that the coverage control scheme outperforms the rate control scheme.