26,150 research outputs found
Highly intensive data dissemination in complex networks
This paper presents a study on data dissemination in unstructured
Peer-to-Peer (P2P) network overlays. The absence of a structure in unstructured
overlays eases the network management, at the cost of non-optimal mechanisms to
spread messages in the network. Thus, dissemination schemes must be employed
that allow covering a large portion of the network with a high probability
(e.g.~gossip based approaches). We identify principal metrics, provide a
theoretical model and perform the assessment evaluation using a high
performance simulator that is based on a parallel and distributed architecture.
A main point of this study is that our simulation model considers
implementation technical details, such as the use of caching and Time To Live
(TTL) in message dissemination, that are usually neglected in simulations, due
to the additional overhead they cause. Outcomes confirm that these technical
details have an important influence on the performance of dissemination schemes
and that the studied schemes are quite effective to spread information in P2P
overlay networks, whatever their topology. Moreover, the practical usage of
such dissemination mechanisms requires a fine tuning of many parameters, the
choice between different network topologies and the assessment of behaviors
such as free riding. All this can be done only using efficient simulation tools
to support both the network design phase and, in some cases, at runtime
Cooperative Coded Data Dissemination for Wireless Sensor Networks
In this poster paper we present a data dissemination transmission abstraction
for over the air programming (OAP) protocol which is fundamentally different
from the previous hop by hop transmission protocols. Instead of imposing the
greedy requirement that at least one node in the ith hop receives all packets
before transmitting packets to the next hop and its neighbours, we take
advantage of the spatial diversity and broadcast nature of wireless
transmission to adopt a cooperative approach in which node broadcast whatever
packets it has received with the expectation that it will recover the lost
packets with high probability by overhearing the broadcast transmissions of its
neighbours. The use of coded transmissions ensures that this does not lead to
the broadcast storm problem. We validate the improved performance our of
proposed transmission scheme with respect to the previous state of the art OAP
protocols on a proof-of-concept two-hops TelosB wireless sensor network
testbed.Comment: This paper appears in: 2016 13th Annual IEEE International Conference
on Sensing, Communication, and Networking (SECON), London, 2016, pp. 1-
LUNES: Agent-based Simulation of P2P Systems (Extended Version)
We present LUNES, an agent-based Large Unstructured NEtwork Simulator, which
allows to simulate complex networks composed of a high number of nodes. LUNES
is modular, since it splits the three phases of network topology creation,
protocol simulation and performance evaluation. This permits to easily
integrate external software tools into the main software architecture. The
simulation of the interaction protocols among network nodes is performed via a
simulation middleware that supports both the sequential and the
parallel/distributed simulation approaches. In the latter case, a specific
mechanism for the communication overhead-reduction is used; this guarantees
high levels of performance and scalability. To demonstrate the efficiency of
LUNES, we test the simulator with gossip protocols executed on top of networks
(representing peer-to-peer overlays), generated with different topologies.
Results demonstrate the effectiveness of the proposed approach.Comment: Proceedings of the International Workshop on Modeling and Simulation
of Peer-to-Peer Architectures and Systems (MOSPAS 2011). As part of the 2011
International Conference on High Performance Computing and Simulation (HPCS
2011
A secure over-the-air programming scheme in wireless sensor networks
Over-The-Air dissemination of code updates in Wireless Sensor Networks (WSNs) have been researchers’ point of interest in past a few years and more importantly security challenges toward remote propagation of code update have taken the majority of efforts in this context. Many security models have been proposed to establish a balance between the energy consumption and security strengthen with having their concentration on constraint nature of WSN nodes. For authentication purposes most of them have used Merkle-Hash-Tree to avoid using multiple public cryptography operations. These models mostly have assumed an environment in which security has to be in a standard level and therefore they have not investigated the tree structure for mission-critical situations in which security has to be in maximum possible extent (e.g. military zones). Two major problems have been identified in Merkle Tree structure which is used in Seluge scheme, including: 1) an exponential growth in number of overhead packets when block size of hash algorithm used in design is increased. 2) Limitation of using hash algorithms with larger block size of 11 bytes when payload size is set to 72 bytes. Then several existing security models are investigated for possible vulnerabilities and a set of countermeasures correspondingly named Security Model Requirements (SMR) is provided. After concentrating on Seluge’s design, a new secure Over-The-Air Programming (OTAP) scheme named Seluge++ is proposed that complies with SMR and replaces the use of inefficient Merkle Tree with a novel method
Architectures for Wireless Sensor Networks
Various architectures have been developed for wireless sensor networks. Many of them leave to the programmer important concepts as the way in which the inter-task communication and dynamic reconfigurations are addressed. In this paper we describe the characteristics of a new architecture we proposed - the data-centric architecture. This architecture offers an easy way of structuring the applications designed for wireless sensor nodes that confers them superior performances
Kompics: a message-passing component model for building distributed systems
The Kompics component model and programming framework was designedto simplify the development of increasingly complex distributed systems. Systems built with Kompics leverage multi-core machines out of the box and they can be dynamically reconfigured to support hot software upgrades. A simulation framework enables deterministic debugging and reproducible performance evaluation of unmodified Kompics distributed systems.
We describe the component model and show how to program and compose event-based distributed systems. We present the architectural patterns and abstractions that Kompics facilitates and we highlight a case study of a complex
distributed middleware that we have built with Kompics. We show how our approach enables systematic development and evaluation of large-scale and dynamic distributed systems
A unified radio control architecture for prototyping adaptive wireless protocols
Experimental optimization of wireless protocols and validation of novel solutions is often problematic, due to limited configuration space present in commercial wireless interfaces as well as complexity of monolithic driver implementation on SDR-based experimentation platforms. To overcome these limitations a novel software architecture is proposed, called WiSHFUL, devised to allow: i) maximal exploitation of radio functionalities available in current radio chips, and ii) clean separation between the logic for optimizing the radio protocols (i.e. radio control) and the definition of these protocols
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