ABSTRACT
Delay-tolerant networks (DTNs) are an emerging class of wireless networks where the next node in the path toward the destination is not known in advance and is chosen dynamically as and when contact opportunities occur. Routing protocols in DTNs tend to create and spread multiple copies of a message to increase the delivery probability, although at the cost of network resources. The chapter presents a state-of-the-art survey of the local-information-based buffer dropping and scheduling policies, and discusses the global buffer management policies. The authors, through simulation analysis, show that local buffer management policies based on local message properties can also give comparable performance to global buffer management policies, which use global message information. The global buffer management policies try to optimize one or more network performance metrics, such as delivery ratio or delivery delay, and derive message utility functions based on network-wide information about the messages.
