Contact quality based forwarding strategy for delay tolerant network

The probabilistic routing protocols accelerate the network traffic towards more vital nodes to achieve high delivery ratio and low delays. However, as the traffic burden rises, the nodes turn into soaked and drop previously stored messages that reduce the delivery ratio and increase end-to-end delay. Hereby it is vital to compute the accurate quality value of nodes. In this paper, we have proposed a Contact Quality Based Forwarding strategy (CQBFS) for city-based environments where nodes are heterogeneous, resources are scarce and traffic density is high. The activity of a node is measured in terms of its ability to transmit the carried message and drop magnitude. Moreover, an effective quality impact based buffer management policy has been used to control the impact of message drop on network throughput. The proposed CQBFS outperforms PRoPHET, Epidemic, Maxprop and TTL based routing protocols in terms of message transmissions, delivery probability, message drop, end-to-end delay and Hop count average under the real time traces Sassy and Helsinki city.