[Show abstract][Hide abstract] ABSTRACT: Machine-to-machine communication (M2M) is a technology to provide interaction among network devices without human intervention. Due to infrastructure characteristics, LTE networks are highly expected to become the deployment network of M2M devices. However, the M2M poses some challenges to these networks, with highlight to the congestion and overload problem over the Radio Access Network (RAN) during the random access procedure caused by the huge number of devices. Thus, mechanisms to control the overload and congestion are required to deal with such scenarios. In this paper, we describe the random access procedure of LTE and we propose a solution to mitigate the impact of the M2M communication. More specifically, we first model how the backoff time should be divided among the H2H and M2M devices as a bankruptcy problem. In a second moment, we apply two solutions for the bankruptcy problem using a game theory framework and an axiomatic approach. The simulations result shows that our approaches present improvements in energy efficiency and controls the impact of M2M devices over H2H. In addition, we also provide priority among M2M devices with high priority and low priority.
Global Information Infrastructure and Networking Symposium (GIIS); 10/2015
[Show abstract][Hide abstract] ABSTRACT: Fault tolerance is one of the most important wireless sensor networks requirements. It ensures that the network continue to function correctly even when some components fail. In fact, fault tolerance is a need in this type of networks due to sensor node characteristics, radio communications and hostile environments in which these networks are deployed. In this survey, we give an overview of WSN mechanisms that provide or improve the fault tolerance property of wireless sensor networks. However, the different solutions presented in this survey are not only intended to mechanisms dedicated to fault tolerance, but they also include all the mechanisms allowing the prevention of fault occurrence such as energy aware routing and data aggregation & compression. Besides the classification of fault tolerance mechanisms according to the tasks they target (data management, flow management), we also propose a new classification based on the network size, since the performance of the majority mechanisms depends on the size in terms of geographical area and number of nodes. Thus, a well performing protocol conceived for small networks may be inadequate for large networks and vice versa.
[Show abstract][Hide abstract] ABSTRACT: Wireless mesh networks (WMNs) are becoming increasingly popular mostly due to their deployment flexibility. The main drawback of these networks is their lack of guaranteeing high Quality of Service (QoS) levels to their clients. The latest ubiquitous mobile and wireless support and significant growth in smartphone features have fueled user demand for rich media services on their devices. Unfortunately, this traffic increase puts additional pressure on WMN resources, eventually affecting user QoS levels and providing solutions to address this is highly challenging. This paper shows how by using ViLBaS, an innovative selective load balancing solution for video deliveries in WMN, increased QoS levels of remotely transmitted video are obtained. ViLBaS employs distributed monitoring of network traffic, identifies the node most affected by congestion and prevents imminent packet drops by rerouting the video flows around the congested node. A hybrid simulation-emulation-based test-bed is built and used for assessing ViLBaS performance in comparison with classic solutions employing the best-known routing metrics. Real video traffic was transmitted from a sever to a client over a WMN topology and the received video quality was assessed in different scenarios. The results demonstrate that ViLBaS outperforms all other solutions when delivering various video content with diverse characteristics and at different quality levels.
[Show abstract][Hide abstract] ABSTRACT: In the recent years, the research community has proposed several protocols and applications for opportunistic networking. These protocols require that all users are willing to cooperate with the network. However, users could have selfish behavior, which can lead to degradations in the network performance. In this work, we propose an incentive mechanism to improve routing, called MINEIRO, which aims to detect and avoid selfish nodes based on the source of the messages. We demonstrate that our algorithm leads to bayeasian equilibrium. Moreover, we analyzed the impact of selfishness in opportunistic networks and showed that without an incentive mechanism, the delivery ratio is constant for up to 60% of nodes with selfish behavior in a network with random node mobility. Meanwhile, our proposal incentivizes rational users to forward messages regardless of the amount of selfish nodes. Resumo. Nosúltimos anos, a comunidade científica propôs diversos protocolos e aplicativos para redes oportunísticas. Estes protocolos requerem que todos os usuários estejam dispostos a cooperar com a rede. No entanto, os usuários podem ter comportamento egoísta, o que pode afetar o desempenho da rede. Neste trabalho, propomos um mecanismo de incentivo para melhoria do rote-amento em redes oportunísticas, chamado MINEIRO, que tem como objetivo detectar e evitar os nós egoístas com base na origem das mensagens recebi-das. O MINEIRO utiliza apenas informações locais. Demonstramos sob quais condições nosso algoritmo atinge o equilíbrio bayesiano em um jogo dinâmico. Além disso, analisamos o impacto do egoísmo em redes oportunísticas e mos-tramos que, sem nenhum mecanismo, a taxa de entregá e constante para até 60% de nós com comportamento egoísta em redes com mobilidade aleatória. Nossa proposta, por sua vez, incentiva os usuários racionais a encaminharem mensagens em qualquer quantidade de nós egoístas. * Os autores gostariam de agradecerà CAPES, COFECUB, CNPq e FAPEMIG pelo apoio financeiro parcial a este trabalho.
Simpósio Brasileiro de Redes de Computadores e Sistemas Distribuídos (SBRC), Vitória - Espirito Santos; 05/2015
[Show abstract][Hide abstract] ABSTRACT: This paper proposes a mechanism for uplink packet scheduler in LTE network in the context of Machine-to-Machine (M2M) communication. The proposed approach uses the current and past information of the system to satisfy the Quality of Service (QoS) requirements, to ensure fairness in resource allocation and to control the congestion caused by M2M devices. We carried out some network simulations by using a NS-3 simulator so as to show the effectiveness of the proposed approach. The results indicate that our solution can reduce the impact of M2M communication on Human-to-Human (H2H) communication and avoid the problem of starvation, when compared to related approaches.
[Show abstract][Hide abstract] ABSTRACT: One of the most common needs in wireless sensor networks (WSNs) is the continuity of network function even in the presence of some node failures. This is called fault tolerance. In general, fault tolerant solutions can be preventive or reactive: The preventive techniques aim to prevent the failure by minimizing and balancing the energy consumption in each node, while the reactive techniques intervene after a failure was detected. In this paper, we propose a new preventive/reactive fault tolerant scheme dedicated to manage the energy consumption and reconnect the WSN in case of articulation node failure. The specificity of this scheme is the use of multichannel communications, allowing simultaneous data transmission, which decreases the interferences between nodes and then decreases data retransmissions. The second task of this scheme targets the reorganization of the network after a network portioning episode. Such episode means that the WSN is partitioned in many segments after an articulation node failure. More precisely, we present here two heuristics for channel allocation/reallocation and WSN reorganization after a network failure. The performances of the proposed scheme is evaluated and proved through simulation.
[Show abstract][Hide abstract] ABSTRACT: In collaborative wireless networks with a low infrastructure, the presence of misbehaving nodes can have a
negative impact on network performance. In particular, we are interested in dealing with this nasty presence in
road safety applications, based on Vehicular Ad hoc Networks (VANETs). Because of its characteristics, namely
high mobility, frequent topology changes, and large deployment areas, verifying safety data validity is difficult, and
existing solutions to tackle this issue are inefficient in VANETs. In this work, we consider as harmful the presence of malicious nodes, which spread false and forged data; and selfish nodes, which cooperate only for their own benefit. To deal with this, we propose DTM2, a Distributed Trust Model, adapted from the Job Market Signaling Model. DTM2 is based on allocating credits to nodes and securely managing these credits. To motivate selfish nodes to cooperate more, our solution establishes the cost of reception to access data, forcing them to earn credits. Moreover, to detect and exclude malicious nodes, DTM2 requires the cost of sending, using signaling values inspired form economics and based on the node’s behavior, so that the more a node is malicious, the higher its sending cost, thus limiting their participation in the network. Similarly, rewards are given to nodes whose sent messages are considered as truthful, and that paid a sending cost considered as correct. The latter is a guarantee for the receivers about the truthfulness of the message since, in case of message refusal, the source node is not rewarded despite its payment. We validated DTM2 via a theoretical study using Markov chains; and with a set of simulations, in both urban and highway scenarios. Both theoretical and simulation results show that DTM2 excludes from the network 100% of malicious nodes, without causing any false positive detection. Moreover, our solution guarantees a good ratio of reception even in the presence of selfish nodes.
[Show abstract][Hide abstract] ABSTRACT: The increasing interest about the Internet of Things (IoT) is almost as remarkable than its practical absence in our everyday lives. Announced as the new breakthrough in IT industry, the domain is characterized by a large number of architecture propositions that are in charge of providing a structure for applications creation. These architectures are needed because of the heterogeneity of stakeholders involved in IoT Applications. Programming languages, operating systems, hardware specificities, processing power, memory, network organization, characteristics, constraints, the world of IoT is so diverse. Furthermore, these architectures should provide an easy access to users that are not aware of IT technologies involved. The Services Oriented Computing (SOC) has shown in the past its relevance to the decoupling constraints interoper-ability among stakeholders. The composition of loosely coupled services facilitates the integration of very varied elements and provides agility in the creation of new applications. But unlike the approach inherited from the SOC in pre-existing services are composed to obtain a specific application, we propose a more dynamic notion of service. Our "Object-as-a-Service" point of view is based on the notion of building dynamically the service needed on each Object and then integrate it in the whole composition. This paper focus on the gain of this approach for the IoT by promoting the 'Object-as-a-Service' paradigm as a basis for the creation of dynamic and agile user-made applications.
Global Information Infrastructure and Networking Symposium - GIIS 2014 -, Montréal; 09/2014
[Show abstract][Hide abstract] ABSTRACT: The development of a system is usually based on shared and accepted require-ments. Hence, to be largely understood by the stakeholders, requirements are often written in natural language (NL). However, checking requirements completeness and consistency requires having them in a formal form. In this article, we focus on user requirements describing a system behaviour, i.e. its behavioural rules. We show how to transform behavioural rules identified from NL requirements and represented within an OWL ontology into the formal specification language Maude. The OWL ontology represents the generic behaviour of a system and al-low us to bridge the gap between informal and formal languages and to automate the transformation of NL rules into a Maude specification.
[Show abstract][Hide abstract] ABSTRACT: Facilitating the creation of Internet of Things (IoT) applications is a major concern to increase its de-velopment. D-LITe, our previous work, is a framework for that purpose. In D-LITe, Objects are considered as part of a whole application. They offer a REST web service that describes Object capabilities, receives the logic to be executed, and interacts with other stakeholders. Then, the complete application is seen as a choreography dynamically deployed on various objects. But the main issue of choreographies is the loss of coherence. Because of their unreliability, some networks used in IoT may introduce de-synchronization between Objects, leading to errors and failures. In this paper, we propose a solution to re-introduce coherence in the application, in order to keep the advantages of choreography while dealing with this main issue. An overlay of logical check-points at the application layer defines links between the coherent states of a set of objects and triggers re-synchronization messages. Correcting statements are thus spread through the network, which enables fault recovery in Choreographies. This paper ends with a comparison between the checking cost and the reliability improvement.
[Show abstract][Hide abstract] ABSTRACT: Service Oriented Computing (SOC) is a common way to build applications/services by composing distributed bricks of logic. Recently, the SOC paradigm has been considered for the design and implementation of Internet of Things (IoT) applications by abstracting objects as service providers or consumers. Based on this trend, we proposed in a previous work D-LITe: a lightweight RESTful virtual machine that allows ubiquitous logic description and deployment for IoT applications using Finite State Transducers (FST). Though D-LITe allows faster and more efficient application creation for heterogeneous objects, it turns out that FST design can be fastidious for inexperienced users. With that in mind, we propose in this paper BeC
3 (Behaviour Crowd Centric Composition) an innovative crowd centric architecture, grounded on D-LITe. It provides a simpler way to compose interactions between IoT components. The idea is to reverse the bottom-up approach of SOC by a rather top-down vision in which the user expresses the expected result of his application by composing behaviours that are proposed by contributors. These behaviours are deployed on each concerned component, which then act exactly as needed to fulfil their role in the composition. The crowd-Centric aspect of this platform allows a community-based design, granting a wide panel of modular and incremental interactions for a wide variety of components. Eventually, BeC
3 will give inexperienced users the ability to organise, interconnect and compose both state of the art web-services and IoT components to create interactive 2.0-like applications for the IoT.
Mobile Networks and Applications 02/2014; 19(1):18-32. DOI:10.1007/s11036-013-0481-8 · 1.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Long Term Evolution (LTE) standard is one
of the most promising technologies of wireless network for
the development of Machine-to-Machine (M2M) communication
because of its high data rates, low latency, high flexibility and
low cost. However, improvements are needed in the network to
support the uplink-heavy traffic generated by M2M communication
and also to ensure the diversity of service requirements
of this communication. The uplink packet scheduler is included
in the necessary improvements. In this article, we evaluate the
performance of the main schedulers for M2M communication
regarding the aspects of service requirements, fairness, energy
efficiency and impact on the system performance of current LTE
[Show abstract][Hide abstract] ABSTRACT: This paper proposes a mechanism for uplink packet scheduler in LTE
network in the context of Machine-to-Machine (M2M) communications that uses
the current and past information of the system to satisfy the Quality of Service
(QoS) requirements, ensure fairness in the allocation of resources and control
the congestion caused by the M2M devices. The results indicate that the proposed
approach can reduce the impact of M2M communication on the Human-to-
Human (H2H) communication and avoid the problem of starvation.
32º Simpósio Brasileiro de Redes de Computadores e Sistemas Distribuídos – SBRC 2014; 01/2014
[Show abstract][Hide abstract] ABSTRACT: In order to check requirement specifications written in natural language, we have chosen to model domain knowledge through an ontology and to formally represent user requirements by its population. Our approach of ontology population focuses on instance property identification from texts. We do so using extraction rules automatically acquired from a training corpus and a bootstrapping terminology. These rules aim at identifying instance property mentions represented by triples of terms, using lexical, syntactic and semantic levels of analysis. They are generated from recurrent syntactic paths between terms denoting instances of concepts and properties. We show how focusing on instance property identification allows us to precisely identify concept instances explicitly or implicitly mentioned in texts.
2013 IEEE 25th International Conference on Tools with Artificial Intelligence (ICTAI); 11/2013