Читать книгу Fog Computing - Группа авторов - Страница 56

Existing works [4, 28] have proposed the frameworks for improving the efficiency of the communication and for application management in the hybrid MFC environment that consist of both iFog and mFog nodes. Essentially, comparing to the UAV-Fog nodes and the UE-fog nodes, the Marine Fog nodes do not have the resource-constraint issue in terms of computation and data storage. However, because the operating marine environment lacks infrastructure, the communication between the Marine Fog nodes and the distant central cloud faces the latency issue derived from the limitation of the underline network topology and technology. For example, the bandwidth of the common VHF radio used in maritime communication can reach only 28.8 kbps and the range of the infrastructure-less 4G/5G LTE device-to-device communication is unable to fulfill the need of a marine environment. In order to overcome the fundamental communication issue, developers may consider integrating UAV-fog nodes [31] in which the system can deploy the UAV-fog nodes between vessels to form a mesh network toward dynamically supporting better bandwidth and more stable connection. However, UAVs have a limited available operation time slot because they are battery-powered. The system needs to introduce an adaptive scheduling scheme, physical location placement scheme. Further, the system needs to dynamically adjust the movement of the UAV-fog nodes based on the interconnected vessels in order to seamlessly maintain the mesh network.