Dynamic Subcarrier Controlled TDMA/OFDM Multi-Hop Wireless Network for Improving End to End Throughput

This paper proposes a dynamic subcarrier utilization method using OFDM among the surrounding multi-hop nodes for improving the bottleneck node caused by unequal link quality of the flow from the source node to the destination node in TDMA multi-hop wireless networks. Although a flexible network can be realized by using multi-hop communication, a hidden node problem occurs between the links in the self flow and degrades the end-to-end throughput performance. As one of the solution of the hidden terminal problem, a TDMA multi- hop wireless network is considered. In TDMA multi-hop wireless network, the transmitting timing can be controlled not to give the interference toward the other links of the self flow. However, the data rate from the source node to the destination node of a fixed TDMA frame size is limited by the lowest quality link with small transmittable bits. As a result, the performance improvement by reducing the interference degrades. In this paper, the dynamic subcarrier assignment method is applied to reduce the effect of bottleneck link of TDMA wireless multi-hop networks. The proposed method can decide the used subcarriers by combining with a routing for establishing the multi-hop network.