Opportunistic Routing Protocols Based on Fuzzy Logic: Present and Future Directions

The intermittent connectivity network under delay tolerant networks is called opportunistic network (OppNet), where there is no direct path between source and destination and does not rely on any central authority. Nodes exchange messages through intermediate nodes in which the message stores waiting for the opportunity to be forwarded to the destination or other cooperative nodes using the concept of store-carry-forward approach. In such a scenario, some critical issues will occur like a low delivery ratio, a long delay, frequent partitions, buffer space management issues. The propsoed research work can overcome all the above issues by designing the routing protocols and many protocols have been proposed based on various techniques like fuzzy logic, neural network, genetic algorithm, machine learning, etc. This paper discusses the opportunistic routing protocols using the concept of fuzzy logic and summarizing them based on their features trying to cover most of the opportunistic routing protocols based on fuzzy logic. This paper classifies the fuzzy logic-based opportunistic routing protocols into two categories, the first one is the message priority and the second is the node selection. The motivation of this paper is to give a wide view of the existing OppNet routing protocols which use the concept of FLC and routing features of each one. This work will allow researchers to find out the appropriate protocol to considered in their research.