Abstract: Because the existing network congestion control routing algorithms in low power and lossy networks (LLN) cannot alleviate the current network congestion effectively,this paper proposed a hybrid-based network congestion control routing algorithm (HNCCRA).This algorithm mainly contains three innovations.Firstly,to reduce the probability of network congestion effectively,each node selects the parent node according to the load state of its alternative parent node in the process of network construction.Secondly,to avoid the problem that the child node of network congestion node selects the alternative parent node with a heavy traffic state as the new parent node when changing the data transmission path,each node notifies its own load status in real time during the maintenance process of the network topology.Finally,for alleviating the current network congestion effectively,network congestion control is conducted by combining the idea of data flow and the way of replacing the data transmission paths.The simulation results show that HNCCRA algorithm can improve the performance of all aspects of the network effectively compared with the existing network congestion control routing algorithm in LLN.Specifically,the network congestion probability is decreased by 19.89%,the average throughput of sink node is increased by 11.35%,and the network lifetime is extended by 9.75%.

Key words: Hybrid, Low power and lossy networks (LLN), Network congestion control, Routing algorithm