A Study on Cooperation Enforcement between Nodes in Mobile Ad Hoc Networks Nor

Traditional infrastructure-based networks are formed around an infrastructure of static, dedicated components that connect the individual end points such as desktop computers and servers. The exponential rise in the number of wireless communication devices will render the provision of infrastructure-based solutions infeasible and researchers have been investigating the provision of alternative communication structures in the form of mobile ad hoc networks (MANETs). A MANET is a collection of low-resourced mobile nodes that communicate over wireless links without the need of fixed infrastructure. The network operates in distributed fashion, where all networking functions including route discovery and packet delivery are executed by the nodes themselves. Nodes in a MANET rely on multi-hop communication to communicate with nodes outside their transmission ranges. However, this can only be realized if all these nodes are willing to cooperate with each other i.e. are not reluctant to forward others’ packets. In selforganized MANETs such as civilian MANETs, each node acts as its own authority and may not share common goals with other nodes. Moreover, nodes in such networks are self-interested and tempted to drop others’ packets to preserve of their own limited resources e.g. battery power and computational capability. Such selfishness and non-cooperative behavior can make it impossible to achieve multi-hop communication and have a negative effect on the overall network performance. A large number of studies have proposed different cooperation enforcement mechanisms for MANETs. In this review paper, we discuss the rationale of cooperation enforcement in MANETs and the characteristics of a cooperation enforcement model. We also review different types of existing approaches to cooperation enforcement in MANETs and analyze them in order to provide justification for moving towards tag-based approach in enforcing cooperation between nodes in MANETs. Then we introduce the concepts found in tag-based cooperation and review existing tag-based approaches.