适用于水下物联网的混合地理路由协议设计

该文针对水下物联网(IoUT)数据传输问题设计了一种混合地理路由协议。海洋环境的复杂性严重地限制了IoUT水下物联网节点间的数据传输性能，因此需要一个高效的路由协议以对抗复杂的信道环境。无状态几何路由(G-STAR)是一种采用贪婪转发模式的地理路由协议，在大多数3维物联网情景中能够找到合适的数据传输路径，然而水下环境中存在诸多不利因素制约了G-STAR的性能。对此，该文提出一个混合G-STAR(Hybrid G-STAR, H-G-STAR)协议，在保有G-STAR优势的基础上对协议在水下环境中的适应性进行了针对性设计。通过增加基于信道监听的无协作转发策略，在节点数量足够时自发地选择信道状况最佳的路径进行路由，由此避开贪婪转发在水下环境中可能遭遇的极端劣化信道。仿真结果显示H-G-STAR协议相较于基准G-STAR协议有着更好的路由性能，并且在物理层能够取得更低的误比特率(BER)，在水下节点的网络拓扑中更为适用。

Hybrid Geographical Routing Protocol for Internet of Underwater Things

The goal of this paper is to design a routing protocol for IoUT data delivery. It is well known that underwater communication is limited by its channel’s hazardous nature, thus efficient routing protocols are needed to compensate for the challenging environments. Geometric STAteless Routing (G-STAR) is a type of geographical routing protocol that forwards messages in a greedy way and obtains sub-optimal results in most 3-dimensional Internet of Things scenarios. Yet the numerous degrading factors in underwater channels limit severely the performance of the G-STAR protocol. In this paper, a Hybrid G-STAR (H-G-STAR) routing protocol continuing the advantage of G-STAR and specifically adapted for underwater conditions is proposed. By introducing a noncooperative routing tactic based on channel listening, the protocol spontaneously searches for the route with the best channel condition whenever the network condition permits and thus avoiding inferior channels greedy routing might encounter. The simulation results show that the proposed protocol improves the routing performance of the network, obtains a lower Bit Error Rate (BER) in the physical layer than G-STAR and is better adapted for underwater network topologies.