1,500 research outputs found
Impact of Obstacles on the Degree of Mobile Ad Hoc Connection Graphs
What is the impact of obstacles on the graphs of connections between stations
in Mobile Ad hoc Networks? In order to answer, at least partially, this
question, the first step is to define both an environment with obstacles and a
mobility model for the stations in such an environment. The present paper
focuses on a new way of considering the mobility within environments with
obstacles, while keeping the core ideas of the well-known Random WayPoint
mobility model (a.k.a RWP). Based on a mesh-partitioning of the space, we
propose a new model called RSP-O-G for which we compute the spatial
distribution of stations and analyse how the presence of obstacles impacts this
distribution compared to the distribution when no obstacles are present.
Coupled with a simple model of radio propagation, and according to the density
of stations in the environment, we study the mean degree of the connection
graphs corresponding to such mobile ad hoc networks
Plausible Mobility: Inferring Movement from Contacts
We address the difficult question of inferring plausible node mobility based
only on information from wireless contact traces. Working with mobility
information allows richer protocol simulations, particularly in dense networks,
but requires complex set-ups to measure, whereas contact information is easier
to measure but only allows for simplistic simulation models. In a contact trace
a lot of node movement information is irretrievably lost so the original
positions and velocities are in general out of reach. We propose a fast
heuristic algorithm, inspired by dynamic force-based graph drawing, capable of
inferring a plausible movement from any contact trace, and evaluate it on both
synthetic and real-life contact traces. Our results reveal that (i) the quality
of the inferred mobility is directly linked to the precision of the measured
contact trace, and (ii) the simple addition of appropriate anticipation forces
between nodes leads to an accurate inferred mobility.Comment: 8 pages, 8 figures, 1 tabl
Reliability of Mobile Agents for Reliable Service Discovery Protocol in MANET
Recently mobile agents are used to discover services in mobile ad-hoc network
(MANET) where agents travel through the network, collecting and sometimes
spreading the dynamically changing service information. But it is important to
investigate how reliable the agents are for this application as the
dependability issues(reliability and availability) of MANET are highly affected
by its dynamic nature.The complexity of underlying MANET makes it hard to
obtain the route reliability of the mobile agent systems (MAS); instead we
estimate it using Monte Carlo simulation. Thus an algorithm for estimating the
task route reliability of MAS (deployed for discovering services) is proposed,
that takes into account the effect of node mobility in MANET. That mobility
pattern of the nodes affects the MAS performance is also shown by considering
different mobility models. Multipath propagation effect of radio signal is
considered to decide link existence. Transient link errors are also considered.
Finally we propose a metric to calculate the reliability of service discovery
protocol and see how MAS performance affects the protocol reliability. The
experimental results show the robustness of the proposed algorithm. Here the
optimum value of network bandwidth (needed to support the agents) is calculated
for our application. However the reliability of MAS is highly dependent on link
failure probability
A Monte Carlo method for the spread of mobile malware
A new model for the spread of mobile malware based on proximity (i.e.
Bluetooth, ad-hoc WiFi or NFC) is introduced. The spread of malware is analyzed
using a Monte Carlo method and the results of the simulation are compared with
those from mean field theory.Comment: 11 pages, 2 figure
On Space-Time Capacity Limits in Mobile and Delay Tolerant Networks
We investigate the fundamental capacity limits of space-time journeys of
information in mobile and Delay Tolerant Networks (DTNs), where information is
either transmitted or carried by mobile nodes, using store-carry-forward
routing. We define the capacity of a journey (i.e., a path in space and time,
from a source to a destination) as the maximum amount of data that can be
transferred from the source to the destination in the given journey. Combining
a stochastic model (conveying all possible journeys) and an analysis of the
durations of the nodes' encounters, we study the properties of journeys that
maximize the space-time information propagation capacity, in bit-meters per
second. More specifically, we provide theoretical lower and upper bounds on the
information propagation speed, as a function of the journey capacity. In the
particular case of random way-point-like models (i.e., when nodes move for a
distance of the order of the network domain size before changing direction), we
show that, for relatively large journey capacities, the information propagation
speed is of the same order as the mobile node speed. This implies that,
surprisingly, in sparse but large-scale mobile DTNs, the space-time information
propagation capacity in bit-meters per second remains proportional to the
mobile node speed and to the size of the transported data bundles, when the
bundles are relatively large. We also verify that all our analytical bounds are
accurate in several simulation scenarios.Comment: Part of this work will be presented in "On Space-Time Capacity Limits
in Mobile and Delay Tolerant Networks", P. Jacquet, B. Mans and G. Rodolakis,
IEEE Infocom, 201
Layered Mobility Model Architecture - LEMMA
This paper presents the
generic layered architecture for mobility
models (LEMMA), which can be used to
construct a wide variety of mobility
models, including the majority of models
used in wireless network simulations. The
fundamental components of the
architecture are described and analyzed,
in addition to its benefits. One of the core
principles stipulates that each mobility
model is divided in five distinct layers that
communicate via interfaces. This allows
their easy replacement and
recombination, which we support by
reviewing 19 layers that can form 480
different mobility models. Some of the
advanced features provided by the
architecture are also discussed, such as
layer aggregation, and creation of hybrid
and group mobility models. Finally, some
of the numerous existing studies of the
different layers are presented
A Classification and Performance Comparison of Mobility Models for Ad Hoc Networks
Abstract. In mobile ad hoc network research, simulation plays an important role in determining the network characteristics and measuring performance. On the other hand, unrealistic simulation conditions may be misleading, instead of being explanatory. For this reason, constructing simulation models closer to the real circumstances is very significant. Movement behavior of mobile entities is one of the most important concepts for the realistic simulation scenarios in mo-bile ad hoc networks. In this study, we first provide a survey and a new hybrid classification of existing mobility models in the literature. We implemented the random direction and boundless simulation area models on Scalable Wireless Ad Hoc Network Simulator (SWANS) and conducted simulations of Ad Hoc On-Demand Distance Vector (AODV) protocol for these as well as the random walk and random waypoint models. Our comparative results for the mobility models are discussed on a variety of simulation settings and parameters.
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