1,863 research outputs found
Towards Opportunistic Data Dissemination in Mobile Phone Sensor Networks
Recently, there has been a growing interest within the research community in developing opportunistic routing protocols. Many schemes have been proposed; however, they differ greatly in assumptions and in type of network for which they are evaluated. As a result, researchers have an ambiguous understanding of how these schemes compare against each other in their specific applications. To investigate the performance of existing opportunistic routing algorithms in realistic scenarios, we propose a heterogeneous architecture including fixed infrastructure, mobile infrastructure, and mobile nodes. The proposed architecture focuses on how to utilize the available, low cost short-range radios of mobile phones for data gathering and dissemination. We also propose a new realistic mobility model and metrics. Existing opportunistic routing protocols are simulated and evaluated with the proposed heterogeneous architecture, mobility models, and transmission interfaces. Results show that some protocols suffer long time-to-live (TTL), while others suffer short TTL. We show that heterogeneous sensor network architectures need heterogeneous routing algorithms, such as a combination of Epidemic and Spray and Wait
Orion Routing Protocol for Delay-Tolerant Networks
In this paper, we address the problem of efficient routing in delay tolerant
network. We propose a new routing protocol dubbed as ORION. In ORION, only a
single copy of a data packet is kept in the network and transmitted, contact by
contact, towards the destination. The aim of the ORION routing protocol is
twofold: on one hand, it enhances the delivery ratio in networks where an
end-to-end path does not necessarily exist, and on the other hand, it minimizes
the routing delay and the network overhead to achieve better performance. In
ORION, nodes are aware of their neighborhood by the mean of actual and
statistical estimation of new contacts. ORION makes use of autoregressive
moving average (ARMA) stochastic processes for best contact prediction and
geographical coordinates for optimal greedy data packet forwarding. Simulation
results have demonstrated that ORION outperforms other existing DTN routing
protocols such as PRoPHET in terms of end-to-end delay, packet delivery ratio,
hop count and first packet arrival
The heterogeneity of inter-contact time distributions: its importance for routing in delay tolerant networks
Prior work on routing in delay tolerant networks (DTNs) has commonly made the
assumption that each pair of nodes shares the same inter-contact time
distribution as every other pair. The main argument in this paper is that
researchers should also be looking at heterogeneous inter-contact time
distributions. We demonstrate the presence of such heterogeneity in the
often-used Dartmouth Wi-Fi data set. We also show that DTN routing can benefit
from knowing these distributions. We first introduce a new stochastic model
focusing on the inter-contact time distributions between all pairs of nodes,
which we validate on real connectivity patterns. We then analytically derive
the mean delivery time for a bundle of information traversing the network for
simple single copy routing schemes. The purpose is to examine the theoretic
impact of heterogeneous inter-contact time distributions. Finally, we show that
we can exploit this user diversity to improve routing performance.Comment: 6 page
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