547 research outputs found
Task allocation in group of nodes in the IoT: A consensus approach
The realization of the Internet of Things (IoT) paradigm relies on the implementation of systems of cooperative intelligent objects with key interoperability capabilities. In order for objects to dynamically cooperate to IoT applications' execution, they need to make their resources available in a flexible way. However, available resources such as electrical energy, memory, processing, and object capability to perform a given task, are often limited. Therefore, resource allocation that ensures the fulfilment of network requirements is a critical challenge. In this paper, we propose a distributed optimization protocol based on consensus algorithm, to solve the problem of resource allocation and management in IoT heterogeneous networks. The proposed protocol is robust against links or nodes failures, so it's adaptive in dynamic scenarios where the network topology changes in runtime. We consider an IoT scenario where nodes involved in the same IoT task need to adjust their task frequency and buffer occupancy. We demonstrate that, using the proposed protocol, the network converges to a solution where resources are homogeneously allocated among nodes. Performance evaluation of experiments in simulation mode and in real scenarios show that the algorithm converges with a percentage error of about±5% with respect to the optimal allocation obtainable with a centralized approach
Equational Reasonings in Wireless Network Gossip Protocols
Gossip protocols have been proposed as a robust and efficient method for
disseminating information throughout large-scale networks. In this paper, we
propose a compositional analysis technique to study formal probabilistic models
of gossip protocols expressed in a simple probabilistic timed process calculus
for wireless sensor networks. We equip the calculus with a simulation theory to
compare probabilistic protocols that have similar behaviour up to a certain
tolerance. The theory is used to prove a number of algebraic laws which
revealed to be very effective to estimate the performances of gossip networks,
with and without communication collisions, and randomised gossip networks. Our
simulation theory is an asymmetric variant of the weak bisimulation metric that
maintains most of the properties of the original definition. However, our
asymmetric version is particularly suitable to reason on protocols in which the
systems under consideration are not approximately equivalent, as in the case of
gossip protocols
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
Security in Wireless Sensor Networks Employing MACGSP6
Wireless Sensor Networks (WSNs) have unique characteristics which constrain them; including small energy stores, limited computation, and short range communication capability. Most traditional security algorithms use cryptographic primitives such as Public-key cryptography and are not optimized for energy usage. Employing these algorithms for the security of WSNs is often not practical. At the same time, the need for security in WSNs is unavoidable. Applications such as military, medical care, structural monitoring, and surveillance systems require information security in the network. As current security mechanisms for WSNs are not sufficient, development of new security schemes for WSNs is necessary. New security schemes may be able to take advantage of the unique properties of WSNs, such as the large numbers of nodes typical in these networks to mitigate the need for cryptographic algorithms and key distribution and management. However, taking advantage of these properties must be done in an energy efficient manner. The research examines how the redundancy in WSNs can provide some security elements. The research shows how multiple random delivery paths (MRDPs) can provide data integrity for WSNs. Second, the research employs multiple sinks to increase the total number of duplicate packets received by sinks, allowing sink voting to mitigate the packet discard rate issue of a WSN with a single sink. Third, the research examines the effectiveness of using multiple random paths in maintaining data confidentiality in WSNs. Last, the research examines the use of a rate limit to cope with packet flooding attacks in WSNs
GOSSIPKIT: A Unified Component Framework for Gossip
International audienceAlthough the principles of gossip protocols are relatively easy to grasp, their variety can make their design and evaluation highly time consuming. This problem is compounded by the lack of a unified programming framework for gossip, which means developers cannot easily reuse, compose, or adapt existing solutions to fit their needs, and have limited opportunities to share knowledge and ideas. In this paper, we consider how component frameworks, which have been widely applied to implement middleware solutions, can facilitate the development of gossip-based systems in a way that is both generic and simple. We show how such an approach can maximise code reuse, simplify the implementation of gossip protocols, and facilitate dynamic evolution and re-deployment
Objects that agree on task frequency in the IoT: A lifetime-oriented consensus based approach
Some key features of the end-systems impact on the way communications happen within the IoT: available objects' resources are limited, different objects may provide the same information (e. g. sense the same physical measure), the number of nodes in the IoT is quickly overcoming the number of Internet hosts with greater reliability issues. This entails for a new paradigm of communication with respect to those characterizing the traditional Internet. Before providing the required information about the physical world, objects coordinate with the other objects in groups and provide a unified service to the external world (the application that requires the service), with the intent to distribute the load of the requested services according to specific community defined rules, which could be: lifetime extension, QoS (Quality of Service) maximization, reward maximization, or others. In this paper other than describing the characteristics of this new communication paradigm and challenges it is called to address, we also propose a first solution for its implementation that relies on a distributed optimization protocol based on the consensus algorithm. Results of simulations and real experiments are also presented that show the viability in implementing the new communication model in a distributed way
A framework for enabling energy efficient semantic views in wireless sensor networks for data intensive applications
Sensor networks have been envisioned to be a promising techniquefor data intensive applications such as disaster management andemergency response and are being designed and deployed for theseapplications. The effectiveness of sensor networksin providing information is determined by human's capacity torecognize and comprehend information from the raw data collected,and act accordingly.Finding relevantinformation from the large amount of data, however, becomes achallenging problem because user interests continues to grow asthe number and variety of sensors increase and users expect toreceive only the data they select to view. Transmitting usersirrelevant data during data processing not only overloads userswith unneeded data but also incurs unnecessary communicationoverhead. Furthermore, the user interests may be correlated when alarge number of users seek information from sensor networks. As aresult, a lot of redundant data transmission can be incurredduring processing in resource-constrained sensor networks. Dataaggregation, though effective in reducing data transmission foraggregated queries, doesn't take the correlation among userinterests into consideration during processing. Therefore,additional techniques need to be proposed to provide efficientinformation delivery for correlated user interests inresource-constrained sensor networks.To bridge the gap between data collected by sensors and the information interests of users, the concept of "semantic view" is proposed in this thesis. The semantic view is a powerful abstraction which allows the fusion of multi-sensor and multi-source data into a virtual data gathering and analysis infrastructure commensurate with the interest of an end user. The main challenge is to enable semantic views in an energy efficient manner in resource constrained sensor networks. To that end, a framework which consists of five protocols and algorithms, "Query Aware Sensing", "Probabilistic Query Dissemination", "Correlated Multi-query Processing", "Location Discovery using Out-of-Range information with multi-lateration" and "End-to-end pairwise key establishment" is presented. In the proposed framework, The ultimate goal is to develop an energy efficient and secure framework towards enabling semantic views in sensor networks for data intensive applications
Bio-Inspired Tools for a Distributed Wireless Sensor Network Operating System
The problem which I address in this thesis is to find a way to organise and manage a network
of wireless sensor nodes using a minimal amount of communication. To find a solution I explore
the use of Bio-inspired protocols to enable WSN management while maintaining a low
communication overhead. Wireless Sensor Networks (WSNs) are loosely coupled distributed
systems comprised of low-resource, battery powered sensor nodes. The largest problem with
WSN management is that communication is the largest consumer of a sensor nodeâs energy.
WSN management systems need to use as little communication as possible to prolong their operational
lifetimes. This is the Wireless Sensor Network Management Problem. This problem
is compounded because current WSN management systems glue together unrelated protocols
to provide system services causing inter-protocol interference. Bio-inspired protocols provide a
good solution because they enable the nodes to self-organise, use local area communication, and
can combine their communication in an intelligent way with minimal increase in communication.
I present a combined protocol and MAC scheduler to enable multiple service protocols to
function in a WSN at the same time without causing inter-protocol interference. The scheduler
is throughput optimal as long as the communication requirements of all of the protocols remain
within the communication capacity of the network. I show that the scheduler improves a dissemination
protocolâs performance by 35%. A bio-inspired synchronisation service is presented
which enables wireless sensor nodes to self organise and provide a time service. Evaluation of
the protocol shows an 80% saving in communication over similar bio-inspired synchronisation
approaches. I then add an information dissemination protocol, without significantly increasing
communication. This is achieved through the ability of our bio-inspired algorithms to combine
their communication in an intelligent way so that they are able to offer multiple services
without requiring a great deal of inter-node communication.Open Acces
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