Probability and topic‐based data transmission protocol

Abstract

SummaryIn the fog computing (FC) models, a fog node supports not only routing functions but also application processes. By the application processes, output data are calculated on input data from sensors and other nodes and sent to target fog nodes which can calculate on the output data. In this article, we consider the mobile topic‐based publish/subscribe fog computing (MPSFC) model where mobile fog nodes communicate with one another by publishing and subscribing messages in wireless networks. Subscription topics of a fog node denote input data on which the node can calculate output data. Publication topics of a message show data carried by the message. In the topic‐based data transmission (TBDT) protocol proposed in our previous studies, while a fewer number of messages are transmitted, the delivery ratio of messages is smaller than the epidemic routing protocol. In this article, we newly propose a pair of time‐to‐live‐based data transmission (TTLBDT) and probability and topic‐based data transmission (PTBDT) protocols in order to increase the delivery ratio. If another node is found in the communication range, a fog node forwards messages to the node. Even if the node is not a target node, the node receives the message with some probability in the PTBDT protocol. In the evaluation, we show the delivery ratios in the TTLBDT and PTBDT protocols are larger than the TBDT protocol. In addition, we show the number of messages exchanged in the PTBDT protocol is smaller than the epidemic routing protocol.