A Two-Way Flow Model for Fog Computing

Abstract

In our previous studies, the TBFC (Tree-Based Fog Computing) model of the IoT is proposed to reduce the electric energy consumed by fog nodes and servers. Here, fog nodes are hierarchically structured in a height-balanced tree. A root node shows a cloud of servers and leaf nodes indicate edge fog nodes which communicate with sensors and actuators. First, sensor data is sent to edge fog nodes. Each fog node receives data from child fog nodes, processes the data, and sends the processed data to a parent fog node. Finally, servers receive sensor data processes by fog nodes and send actions to actuators. Thus, sensor data is sent upwards to a root node from sensors and action are sent downward to actuators from the root node. In order to more promptly deliver actions to actuators, we newly propose a TWTBFC (Two-Way TBFC) model where fog nodes not only send processed data to a parent fog node but also send both the processed data and data received from the child fog node to each child fog node. Thus, each fog node can get more global information, i.e. not only data from child fog nodes but also data from sibling fog nodes. Fog nodes nearer to edge fog nodes decide on actions by using the data and send the actions to child fog nodes.