In this paper, we develop a traffic load-based resource allocation scheme, called LOAD, to enhance the capacity of relayed wireless access networks for asymmetric traffic load such as transmission control protocol (TCP). In order to estimate the current traffic load status in relayed wireless access networks, we propose a load estimation method. A relay gateway estimates the current traffic load status by keeping track of the sizes of the frames it encounters, and computes accordingly the current traffic load of the uplink and the downlink. The results are then used to allocate the system resource between the uplink and the downlink. The proposed method can be implemented without the modification of the deployed IEEE 802.11 nodes.
We analyze the throughput ratio between the uplink and the downlink, and validate the analysis result with a comprehensive simulation study. The simulation results indicate that the utilization of the proposed method is better than that of IEEE 802.11 Distributed Coordination Function (DCF).