Avoiding Bottlenecks Due to Traffic Aggregation at Relay Nodes in Multi-hop Wireless Networks

In multi-hop wireless networks all nodes are potentially routers, forwarding traffic on behalf of other users. Some scenarios (e.g. gateways to Internet, mesh networks) may lead to some nodes forwarding more traffic than others. When using IEEE 802.11 with RTS/CTS, these relay nodes become a significant performance bottleneck in the network. Previous research has attempted to overcome this bottleneck by giving priority to the relay nodes and implementing congestion control schemes. We propose a new scheme where a relay node avoids congestion by only responding to RTS frames when its receiving and forwarding rates are balanced. This avoids adverse affects of significant changes to the RTS/CTS scheme, and (as shown by simulations) provides significant throughput increases over ordinary RTS/CTS and almost equivalent throughput/delay as the other proposed schemes.