Coordinated LTE uplink radio interface scheduling

Long Term Evolution (LTE) promises substantially higher radio interface throughput compared to 3G access technologies. Sometimes, the bandwidth demands of a time varying LTE user traffic cannot be fulfilled by the existing transport network either due to the limited capacity or because of the inaccuracies involved in the transport link bandwidth dimensioning. This often results in a congestion situation in the transport network. In this study a novel congestion control scheme is introduced for the LTE uplink which works based on the coordination between the limited transport network capacity and the time varying radio interface capacity. The proposed mechanism operates at the eNB where the two network interfaces can be monitored in order to efficiently minimize the congestion situations. The coordination based congestion control algorithm is implemented in an LTE network simulator and its performance is studied for various system load configurations. The simulation results confirm that the proposed algorithm effectively mitigates the congestion and helps achieve an improved uplink application performance. Furthermore, a significant application performance gain is also observed for the downlink applications when the congestion in the uplink is controlled.