PASOR: A Packet Salvaging Model for Opportunistic Routing Protocols

Opportunistic Routing (OR) protocols are known as a promising research area with the aim of delivering data packets to their destination more reliably. Security of such protocols, however, is still an open, and challenging research problem. In this paper, we propose an enhancement on OR protocols which benefits from an appropriate candidate coordination mechanism, and assists in salvaging data packets that are dropped by malicious nodes. More precisely, an analytical approach is proposed using Discrete-Time Markov Chain (DTMC) to model a packet salvaging mechanism in an OR-based wireless network, while malicious nodes attempt in degrading the network performance. The proposed model demonstrates how back-up candidates in the candidate set can help in salvaging dropped packets by supervising the behavior of other peers in the candidate set. Different network parameters including packet delivery, drop, salvage, and direct-delivery ratio are then extracted from the introduced model. Furthermore, the model is applied on a well-known OR protocol and is evaluated using both analytical approach, and network simulations. Evaluation results represent that the introduced model can dramatically boost the performance of a wireless network by delivering greater number of packets to their destination compared to a baseline protocol.