Swarm-RE: Hierarchical Opportunistic Routing and Fast Terrain Exploration in Planetary Surface

Wireless sensor networks (WSNs) can be applied to planetary surface exploration due to the advantages of large coverage areas, low cost, and all-time monitoring. However, obtaining sensor data stably and efficiently is difficult due to energy constraints and environmental interference. In this paper, we propose Swarm-Re, including hierarchical heterogeneous opportunistic routing (HHOR) for cooperative air-ground network communication and fast terrain exploration algorithm to collect information efficiently. The sensor nodes are clustered by the DBSCAN algorithm based on the estimated SNR and network connectivity. For cross-cluster communication, HHOR deploys UAV nodes to achieve obstacle crossing. Through the experiment of Swarm-RE, HHOR consumes the least energy and accomplishes a high data delivery rate compared with representative routing protocols. The HHOR protocol shows the lowest expected end-to-end delay and highest channel utilization in both intra-cluster and cross-cluster communications. Relying on HHOR and UAV deployment, the Fast exploration algorithm can improve the efficiency with an average of 11s per Number of UAV. The result shows that the Swarm-RE provides efficient routine and exploration ability in planetary surface.