2,841 research outputs found
The impact of mobility models on the performance of mobile Ad Hoc network routing protocol
A mobility model represents nodes distribution and movement over the network. Several research works have shown that a selection of mobility model can affect the outcome of routing performance simulation in Mobile Ad Hoc Networks. Thus, a routing protocol may only be effective in a particular mobility model or scenario but performs inferiorly in another. As a result, analyses of routing protocol performance are often based on inadequate information leading to inaccurate argument and conclusion. In this paper, three different mobility models have been selected, where each of them is highly distinctive in terms of nodes movement behavior. In addition, a new measurement technique called probability of route connectivity is introduced. The technique is used to quantify the success rate of route established by a routing protocol. Extensive simulation runs are done and results are compared between each mobility model
Transform-based Distributed Data Gathering
A general class of unidirectional transforms is presented that can be
computed in a distributed manner along an arbitrary routing tree. Additionally,
we provide a set of conditions under which these transforms are invertible.
These transforms can be computed as data is routed towards the collection (or
sink) node in the tree and exploit data correlation between nodes in the tree.
Moreover, when used in wireless sensor networks, these transforms can also
leverage data received at nodes via broadcast wireless communications. Various
constructions of unidirectional transforms are also provided for use in data
gathering in wireless sensor networks. New wavelet transforms are also proposed
which provide significant improvements over existing unidirectional transforms
Toward an efficient solution for dynamic ad hoc network interoperability
An ad hoc network is formed by an impromptu grouping of network capable nodes. The nodes forming the network have unconstrained mobility, and so provide a dynamic network topology. Current work in this research area has focused on designing routing protocols capable of efficiently forwarding packets in these dynamic network environments. This has led to several designs for ad hoc routing protocols based on various routing algorithms, each suited to specific usage characteristics. This paper will discuss issues relating to routing in ad hoc networks. We will describe an active networking based solution that provides dynamic routing protocol interoperability and enables migration of nodes between ad hoc groups. Our design is motivated by a squad and base scenario which consists of two groups wishing to communicate. These groups have contrasting deployment characteristics and so use different routing protocols
On the Experimental Evaluation of Vehicular Networks: Issues, Requirements and Methodology Applied to a Real Use Case
One of the most challenging fields in vehicular communications has been the
experimental assessment of protocols and novel technologies. Researchers
usually tend to simulate vehicular scenarios and/or partially validate new
contributions in the area by using constrained testbeds and carrying out minor
tests. In this line, the present work reviews the issues that pioneers in the
area of vehicular communications and, in general, in telematics, have to deal
with if they want to perform a good evaluation campaign by real testing. The
key needs for a good experimental evaluation is the use of proper software
tools for gathering testing data, post-processing and generating relevant
figures of merit and, finally, properly showing the most important results. For
this reason, a key contribution of this paper is the presentation of an
evaluation environment called AnaVANET, which covers the previous needs. By
using this tool and presenting a reference case of study, a generic testing
methodology is described and applied. This way, the usage of the IPv6 protocol
over a vehicle-to-vehicle routing protocol, and supporting IETF-based network
mobility, is tested at the same time the main features of the AnaVANET system
are presented. This work contributes in laying the foundations for a proper
experimental evaluation of vehicular networks and will be useful for many
researchers in the area.Comment: in EAI Endorsed Transactions on Industrial Networks and Intelligent
Systems, 201
Delay-bounded medium access for unidirectional wireless links
Consider a wireless network where links may be
unidirectional, that is, a computer node A can broadcast
a message and computer node B will receive this
message but if B broadcasts then A will not receive it.
Assume that messages have deadlines. We propose a
medium access control (MAC) protocol which replicates
a message in time with carefully selected pauses between
replicas, and in this way it guarantees that for every
message at least one replica of that message is
transmitted without collision. The protocol ensures this
with no knowledge of the network topology and it
requires neither synchronized clocks nor carrier sensing
capabilities. We believe this result is significant because
it is the only MAC protocol that offers an upper bound
on the message queuing delay for unidirectional links
without relying on synchronized clocks
Giving neurons to sensors. QoS management in wireless sensors networks
Public utilities services (gas, water and electricity)
have been traditionally automated with several technologies. The
main functions that these technologies must support are AMR,
Automated Meter Reading, and SCADA, Supervisory Control
And Data Acquisition. Most meter manufacturers provide devices
with Bluetoothr or ZigBeeTM communication features. This characteristic
has allowed the inclusion of wireless sensor networks
(WSN) in these systems. Once WSNs have appeared in such
a scenario, real-time AMR and SCADA applications can be
developed with low cost. Data must be routed from every meter to
a base station. This paper describes the use of a novel QoS-driven
routing algorithm, named SIR: Sensor Intelligence Routing, over
a network of meters. An arti cial neural network is introduced
in every node to manage the routes that data have to follow. The
resulting system is named Intelligent Wireless Sensor Network
(IWSN)
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