4,836 research outputs found
PS-Sim: A Framework for Scalable Simulation of Participatory Sensing Data
Emergence of smartphone and the participatory sensing (PS) paradigm have
paved the way for a new variant of pervasive computing. In PS, human user
performs sensing tasks and generates notifications, typically in lieu of
incentives. These notifications are real-time, large-volume, and multi-modal,
which are eventually fused by the PS platform to generate a summary. One major
limitation with PS is the sparsity of notifications owing to lack of active
participation, thus inhibiting large scale real-life experiments for the
research community. On the flip side, research community always needs ground
truth to validate the efficacy of the proposed models and algorithms. Most of
the PS applications involve human mobility and report generation following
sensing of any event of interest in the adjacent environment. This work is an
attempt to study and empirically model human participation behavior and event
occurrence distributions through development of a location-sensitive data
simulation framework, called PS-Sim. From extensive experiments it has been
observed that the synthetic data generated by PS-Sim replicates real
participation and event occurrence behaviors in PS applications, which may be
considered for validation purpose in absence of the groundtruth. As a
proof-of-concept, we have used real-life dataset from a vehicular traffic
management application to train the models in PS-Sim and cross-validated the
simulated data with other parts of the same dataset.Comment: Published and Appeared in Proceedings of IEEE International
Conference on Smart Computing (SMARTCOMP-2018
Evaluating On-demand Pseudonym Acquisition Policies in Vehicular Communication Systems
Standardization and harmonization efforts have reached a consensus towards
using a special-purpose Vehicular Public-Key Infrastructure (VPKI) in upcoming
Vehicular Communication (VC) systems. However, there are still several
technical challenges with no conclusive answers; one such an important yet open
challenge is the acquisition of shortterm credentials, pseudonym: how should
each vehicle interact with the VPKI, e.g., how frequently and for how long?
Should each vehicle itself determine the pseudonym lifetime? Answering these
questions is far from trivial. Each choice can affect both the user privacy and
the system performance and possibly, as a result, its security. In this paper,
we make a novel systematic effort to address this multifaceted question. We
craft three generally applicable policies and experimentally evaluate the VPKI
system performance, leveraging two large-scale mobility datasets. We consider
the most promising, in terms of efficiency, pseudonym acquisition policies; we
find that within this class of policies, the most promising policy in terms of
privacy protection can be supported with moderate overhead. Moreover, in all
cases, this work is the first to provide tangible evidence that the
state-of-the-art VPKI can serve sizable areas or domain with modest computing
resources.Comment: 6 pages, 7 figures, IoV-VoI'1
The Dynamics of Vehicular Networks in Urban Environments
Vehicular Ad hoc NETworks (VANETs) have emerged as a platform to support
intelligent inter-vehicle communication and improve traffic safety and
performance. The road-constrained, high mobility of vehicles, their unbounded
power source, and the emergence of roadside wireless infrastructures make
VANETs a challenging research topic. A key to the development of protocols for
inter-vehicle communication and services lies in the knowledge of the
topological characteristics of the VANET communication graph. This paper
explores the dynamics of VANETs in urban environments and investigates the
impact of these findings in the design of VANET routing protocols. Using both
real and realistic mobility traces, we study the networking shape of VANETs
under different transmission and market penetration ranges. Given that a number
of RSUs have to be deployed for disseminating information to vehicles in an
urban area, we also study their impact on vehicular connectivity. Through
extensive simulations we investigate the performance of VANET routing protocols
by exploiting the knowledge of VANET graphs analysis.Comment: Revised our testbed with even more realistic mobility traces. Used
the location of real Wi-Fi hotspots to simulate RSUs in our study. Used a
larger, real mobility trace set, from taxis in Shanghai. Examine the
implications of our findings in the design of VANET routing protocols by
implementing in ns-3 two routing protocols (GPCR & VADD). Updated the
bibliography section with new research work
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