Objective   In order to solve the problems of the large communication data volume and high transmission delay of unmanned surface vessels (USVs), a USV multi-constrained network transmission routing algorithm (USMCRA) is proposed under the software-defined network (SDN) architecture suitable for USVs.

  Method  By establishing a USV network model with SDN architecture, the routing problem in the network is transformed into a multi-constrained shortest path problem, and the algorithm is used to select the appropriate routing node to complete the data transmission. Obtain the state information in the network link through the SDN controller, take the bandwidth, delay and data stream size as constraints, and implement this algorithm in combination with the Dijkstra algorithm design. In the simulation experiment, the USV network model is built through the mininet simulation platform, and the USMCRA algorithm is designed in the RYU controller to realize the network simulation.

  Results  The results show that the routing algorithm improves the transmission efficiency and stability of a USV network. Compared with the traditional network architecture, the network transmission rate with the USMCRA algorithm is increased by about 16%, and the peak value of the network jitter is controlled at 0.2 ms, realizing network optimization.

  Conclusion   The proposed USMCRA algorithm provides a new solution for the problems of large communication data volume and high transmission delay experienced by USVs.