Evaluating contacts in opportunistic networks over more realistic simulation models

Abstract

Opportunistic Networks (ONs) are mobile networks that support intermittent links and long delays. ON nodes exchange data in brief moments called contacts, when another node is within radio range. Contacts are ephemeral and unpredictable, thus they must be implemented as efficiently as possible. However, most previous work rely on simplistic assumptions such as unlimited bandwidth and contentionfree transmissions. This paper presents a more realistic evaluation of ON contacts. Simulations show that, on opposition to the consensus in the literature, routing protocols that forward more copies and those that determine a subset of nodes to receive the Bundles using a certain criteria outperform flooding-based protocols, because the latter generates too much medium contention. Finally, buffer management and forwarding prioritization may influence the performance of the network by up to 30%.

Congestion Control Strategies on Integrated Routing Protocol for the Opportunistic Network: A Comparative Study and Performance Analysis

“…The excessive multi-copies spraying in the network cause serious network congestion by exhausting the nodes, there by influencing the performance of transmission [9]. In opportunistic networks, no end-to-end connection is established and therefore congestion cannot be detected and controlled by a feedback loop [17], [18].…”