ABSTRACT
The opportunistic network is one of the most interesting evolution of Mobile Ad-hoc Network (MANET).In an opportunistic network,information about the context in which users communicate is notavailable as there is no dedicated complete path from a source to a destination. This makes the design of an efficient routing protocol for an opportunistic network difficult. The research is aimed at the development of an improved integrated routing protocol in opportunistic networks. Simulation was carried out using the opportunistic network environment (ONE) simulator.This report presents the modeled opportunistic network using the epidemic, the prophet and the integrated routing protocol. Four pre-emptive congestion control strategies (use of acknowledgement, buffer size advertisement, data centric method and the avoidance of duplication) were developed and incorporated into the integrated routing protocol. The integrated routing protocol outperformed the epidemic and the prophet routing protocols by 5.4% and 4.3%, respectively with respect to the delivery probability. Results showed that the duplication avoidance improved the integrated routing protocol because it reduced the packet loss and improved the delivery probability when tested on a 10-node test model and on the benchmark Helsinki simulation area. Duplication avoidance reduced the packet loss by 58% and improved the delivery probability by 4% at the end of the simulation time of 43200 seconds when compared with the delivery probability and packet loss of the original integrated routing protocol on Helsinki which are 0.1048 and 670, respectively. The use of acknowledgement, buffer size advertisement, data centric method reduced the packet loss by 2.5%, 57% and 57%, respectively but did not improve on the delivery probability significantly. The final delivery probabilities ofthe use of acknowledgement, buffer size advertisement, data centric method are 0.105, 0.103 and 0.105, respectively. These results showed that duplication avoidance is the preferred congestion control strategy for the integrated routing considered in this research.