PFCS: Pre-buffering-aware flow control scheme for LTE-advanced relay networks

Relay technology is one of the techniques proposed to enhance the capacity of Long Term Evolution-Advanced (LTE-A) networks. In an LTE-A relay network, each serving relay node has to store packets for its mobile users and forward the remaining packets to another node during handover. However, increasing the number of forwarded packets will result in the degradation of the users throughput. Flow control and pre-buffering schemes are the two main schemes proposed to reduce the number of forwarded packets in LTE-A relay networks. Existing studies assumes the two schemes are independently operated. However, ignoring the effect of buffer overflow at the pre-buffering queue in a flow control scheme may result in ineffective operation. This paper presents a pre-buffering-aware flow control scheme (PFCS) for an LTE-A relay network that jointly considers the effects of both flow control and pre-buffering schemes. The proposed PFCS can significantly improve user's throughput by preventing both buffer overflow and buffer underflow of the local queue at the serving relay node and minimizing the number of forwarded packets. Simulation results show that the PFCS can provide a better throughput than the traditional flow control schemes because the effect of the pre-buffering scheme can minimize the number of forwarded packets.