On Multicopy Opportunistic Forwarding Protocols in Nondeterministic Delay Tolerant Networks
Delay Tolerant Networks (DTNs) are characterized by nondeterministic mobility and connectivity. Message routing in DTNs usually employs a multi-copy forwarding scheme. To avoid the cost associated with flooding, much effort has been focused on opportunistic forwarding, which aims to reduce the cost of forwarding while retaining high routing performance by forwarding messages only to nodes that have high delivery probabilities. This paper presents two multi-copy forwarding protocols, called Optimal Opportunistic Forwarding (OOF) and OOF-, which maximize the expected delivery rate and minimize the expected delay, respectively, while requiring that the number of forwarding's per message does not exceed a certain threshold.