Effectiveness and fairness tradeoff for TCP using cross-layer design in UMTS system

In W-CDMA (Wideband Code Division Multiple Access)/UMTS (Universal Mobile Telecommunications System), multiuser contention brought by packet scheduling in MAC-layer causes the issue that effectiveness requirements and fairness requirements for TCP in transport-layer are difficult to be guaranteed simultaneously. In order to solve this problem, we propose a novel scheme CL-AACS (active ACK control strategy with cross-layer information interaction) to improve TCP performance in UMTS that its basic idea is to embed CL-AACS module in base stations to control reverse ACK forwarding by the information communicated between MAC-layer and transport-layer in order that all users can have fair TCP throughput as well as the maximization of wireless link resources utilization. Simulation results show that the scheme CL-AACS makes effectiveness and fairness tradeoff for TCP over W-CDMA/UMTS effectively.