PCV: Predicting contact volume for reliable and efficient data transfers in opportunistic networks

Abstract

Exploiting opportunistic contacts between mobile devices to enable deployment of real applications through reliable and efficient data transfers poses a significant research challenge. Indeed, accurate prediction of contact volume, defined as the maximum amount of data transferable during a contact, can improve performance of deployments. However, existing schemes for estimating contact volume that make use of preconceived patterns or contact time distributions may not be applicable in uncertain environments. In this paper, we propose a novel scheme called PCV that predicts contact volume in soft real-time to enable efficient and reliable data transfers in opportunistic networks. An Android Application that learns data rate profiles has been developed to facilitate PCV. In addition, an analytical model has been developed to depict variable data rates between mobile devices. Extensive simulations are carried out on both synthetic and real world mobility traces to validate the usefulness of PCV. Experimental results show the effectiveness of our approach in terms of reliable data transfers.

COSC: Paths with Combined Optimal Stability and Capacity in opportunistic networks

“…When two mobile nodes v x and v y make contact for a duration of t 0 xy , the amount of data can be transferred depends on their velocity vectors [21]. Maximum amount of data that can be transferred between a pair of opportunistically meeting nodes v x and v y is given by…”

“…COSC exploits repeating trajectories embedded in the mobility histories of participating nodes. While our previous work [21] estimates contact volume that can be transferred during an opportunistic contact, the work presented in this paper estimates capacity of an opportunistic path.…”

“…It is assumed that human mobility follows repeating trajectories, this predictive path lookup can reduce significant amount of overhead messages and result in packet delivery improvement. In COSC, each edge (or link) weight between two nodes of the TVG corresponds to the contact volume [21] when the two nodes come into contact. The effective capacity of a path from a source to a destination is the capacity of the bottleneck link.…”

CONNECT: Consociating opportunistic network neighbors for constructing a consistent and connected virtual backbone

“…For example, in case of direct communication between neighbors, the contact duration may not be enough to transfer the whole data stream [16]. If we decide to complete the transmission exploiting multiple contact opportunities with the neighbor, it may take a long time to finish.…”

“…If we decide to complete the transmission exploiting multiple contact opportunities with the neighbor, it may take a long time to finish. Even in many cases, the transmitting neighbor may miss out and never meet again soon [16].…”