3,028 research outputs found
A Lightweight Content Replication Scheme for Mobile Ad Hoc Environments
The mobile, wireless, and self-organizing features of ad hoc networks pose many challenges with respect to continuous availability and accessibility of data. In such a dynamic environment, there are many advantages in replicating a data item so there are multiple copies, including reduced response times and higher data availability. Also, if done efficiently, replication can help reduce energy usage. In this paper, we propose the Expanding Ring replication strategy for pull-based information dissemination environments. One of our primary objectives is the development of a lightweight scheme for mobile nodes. We evaluate the performance of our scheme with respect to a number of parameters and compare it to a system without replication. Our results show a reduction in the average response times and the message processing overhead on nodes. The scheme also does well when both, the overall willingness of nodes to cache data and their individual caching capabilities vary
A Lightweight Distributed Solution to Content Replication in Mobile Networks
Performance and reliability of content access in mobile networks is
conditioned by the number and location of content replicas deployed at the
network nodes. Facility location theory has been the traditional, centralized
approach to study content replication: computing the number and placement of
replicas in a network can be cast as an uncapacitated facility location
problem. The endeavour of this work is to design a distributed, lightweight
solution to the above joint optimization problem, while taking into account the
network dynamics. In particular, we devise a mechanism that lets nodes share
the burden of storing and providing content, so as to achieve load balancing,
and decide whether to replicate or drop the information so as to adapt to a
dynamic content demand and time-varying topology. We evaluate our mechanism
through simulation, by exploring a wide range of settings and studying
realistic content access mechanisms that go beyond the traditional
assumptionmatching demand points to their closest content replica. Results show
that our mechanism, which uses local measurements only, is: (i) extremely
precise in approximating an optimal solution to content placement and
replication; (ii) robust against network mobility; (iii) flexible in
accommodating various content access patterns, including variation in time and
space of the content demand.Comment: 12 page
Content Replication in Mobile Networks
Performance and reliability of content access in mobile networks is conditioned by the number and location of content replicas deployed at the network nodes. In this work, we design a practical, distributed solution to content replication that is suitable for dynamic environments and achieves load balancing. Simulation results show that our mechanism, which uses local measurements only, approximates well an optimal solution while being robust against network and demand dynamics. Also, our scheme outperforms alternative approaches in terms of both content access delay and access congestio
A Marketplace for Efficient and Secure Caching for IoT Applications in 5G Networks
As the communication industry is progressing towards
fifth generation (5G) of cellular networks, the traffic it
carries is also shifting from high data rate traffic from cellular
users to a mixture of high data rate and low data rate traffic
from Internet of Things (IoT) applications. Moreover, the need
to efficiently access Internet data is also increasing across 5G
networks. Caching contents at the network edge is considered
as a promising approach to reduce the delivery time. In this
paper, we propose a marketplace for providing a number of
caching options for a broad range of applications. In addition,
we propose a security scheme to secure the caching contents
with a simultaneous potential of reducing the duplicate contents
from the caching server by dividing a file into smaller chunks.
We model different caching scenarios in NS-3 and present the
performance evaluation of our proposal in terms of latency and
throughput gains for various chunk sizes
File management in a mobile DHT-based P2P environment
The emergence of mobile P2P systems is largely due to the evolution of mobile devices into powerful information processing units. The relatively structured context that results from the mapping of mobile patterns of behaviour onto P2P models is however constrained by the vulnerabilities of P2P networks and the inherent limitations of mobile devices. Whilst the implementation of P2P models gives rise to security and reliability issues, the deployment of mobile devices is subject to efficiency constraints. This paper presents the development and deployment of a mobile P2P system based on distributed hash tables (DHT). The secure, reliable and efficient dispersal of files is taken as an application. Reliability was addressed by providing two methods for file dispersal: replication and erasure coding. Security constraints were catered for by incorporating an authentication mechanism and three encryption schemes. Lightweight versions of various algorithms were selected in order to attend to efficiency requirements
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