MANETs will play a critical role for communication in future battlefields. However, wireless communications, especially MANETs are susceptible to jamming. While MANETs will adapt to continuous jamming, intermittent jamming can disrupt the routing protocol. In the intermittent case, the network topology during non-jamming is generally quite different from the one during jamming. In the case of jamming by the enemy, one can use physical means to stop the jamming. However, in recent conflicts, jamming by friendly forces has been widely used. In this paper, we propose the jamming-aware routing protocols for the friendly jamming scenario where the jamming schedule (i.e., when jamming is to occur) is known to the friendly mobile nodes, but hidden from all enemy mobile nodes. The key idea is that the routing protocol freezes during jamming, whereas it resumes during non-jamming. This simple, but very effective, algorithm significantly improves the packet delivery ratio and other metrics compared to other routing protocols where the categories of the routing protocols considered are proactive and unicast with single-path or multipath. Finally, this paper concludes with a discussion on a routing protocol, which combines game-theoretic routing with jamming detection and probabilistic forwarding to avoid and overcome malicious jamming.

We propose a Context-aware Smallworld routing protocol for wireless ad-hoc networks which finds efficient routes to the destination nodes often through a very short chain of intermediate nodes, without using any routing table. This protocol exploits the “small-world” phenomenon of social networks where source-destination pairs typically get connected through few intermediate friends and the individuals can collectively discover such short paths. The key idea behind our routing protocol is that for forwarding an incoming packet to the destination, a node picks the next hop from among the one-hop neighbor from its one-hop neighborhood that is closest to the destination, and multiple randomly selected long-distance neighbor(s), i.e., from outside of its one-hop neighborhood, based on which of these neighbors is closest to the destination. The long-distance neighbors are selected by using their contextual information through a probabilistic mapping. We provide the theoretical foundations behind our protocol. This simple but effective algorithm can meet performance objectives for most scenarios by reducing loss and latency. Simulation results, using synthetic network topologies, have demonstrated that the routing performance of context-aware Smallworld is better than geographical (distance-based) Smallworld and other standard proactive routing protocols (e.g., OLSRv2) when metrics, such as packet losses, end-to-end delays, hop-counts, connectivity drops, and control traffic generated, are used as the key performance indicators. We also show that the proposed protocol is resilient to dynamic topology changes.