Opportunistic Scheduling Algorithm Based on Congestion in Wireless Ad hoc Networks

In wireless multi-hop Ad hoc networks, nodes need to contend for the shared wireless channel, this could result in partial congestion in the network and degrade the network performance. And first in first out (FIFO) queue within a node could easily cause the head-of-line blocking problem. A novel congestion-based opportunistic scheduling (CBOS) algorithm is proposed. In CBOS, the sender sends multicast request to send (RTS) frame targeted to several receivers, and the receivers would reply priority-based clear to send (CTS) by the probability according to its queue congestion status. The simulation results show that CBOS can remarkably increase the network end-to-end saturation throughput and the utilization ratio of wireless channel, and can increase the fairness among traffic flows.