International audience ; Disasters lead to devastating structural damage not only to buildings and transport infrastructure, but also to other critical infras-tructure, such as the power grid and communication backbones. Follow-ing such an event, the availability of minimal communication services is however crucial to allow efficient and coordinated disaster response, to enable timely public information, or to provide individuals in need with a default mechanism to post emergency messages. The Internet of Things consists in the massive deployment of heterogeneous devices, most of which battery-powered, and interconnected via wireless network interfaces. Typical IoT communication architectures enables such IoT devices to not only connect to the communication backbone (i.e. the Internet) using an infrastructure-based wireless network paradigm, but also to communicate with one another autonomously, without the help of any infrastructure, using a spontaneous wireless network paradigm. In this paper, we argue that the vast deployment of IoT-enabled devices could bring benefits in terms of data network resilience in face of disas-ter. Leveraging their spontaneous wireless networking capabilities, IoT devices could enable minimal communication services (e.g. emergency micro-message delivery) while the conventional communication infras-tructure is out of service. We identify the main challenges that must be addressed in order to realize this potential in practice. These chal-lenges concern various technical aspects, including physical connectivity requirements, network protocol stack enhancements, data traffic priori-tization schemes, as well as social and political aspects.
International audience ; In military or emergency scenarios (like Disaster Relief), the area where the terrestrial forces are located is not always easy to cover. In such an area, no infrastructure is available (never deployed or unavailable due to disaster for instance), persons are located in many locations, eventually structured in groups, but distant from one to another. The topology may also introduce difficulties (canyons, mountains, vegetation.). In such scenarios, communications in a group may be done using ad-hoc networks principle, but the communications from one group to another can be compared to the interconnection of ad-hoc networks. We propose in this paper to interconnect these terrestrial ad-hoc networks with a geostationary DVB-RCS system. This satellite network allows us not only to interconnect the groups, but also to provide them with an access to a very far headquarters and also to the Internet, thanks to the bidirectional link supported by these satellite systems. DVB-S/RCS systems, mobility protocols and ad-hoc network protocols are first presented separately. The global architecture is then defined. Each kind of architecture is evaluated alone. Finally, architectures performances are compared to each other and the results are discussed as a conclusion.
International audience ; In military or emergency scenarios (like Disaster Relief), the area where the terrestrial forces are located is not always easy to cover. In such an area, no infrastructure is available (never deployed or unavailable due to disaster for instance), persons are located in many locations, eventually structured in groups, but distant from one to another. The topology may also introduce difficulties (canyons, mountains, vegetation.). In such scenarios, communications in a group may be done using ad-hoc networks principle, but the communications from one group to another can be compared to the interconnection of ad-hoc networks. We propose in this paper to interconnect these terrestrial ad-hoc networks with a geostationary DVB-RCS system. This satellite network allows us not only to interconnect the groups, but also to provide them with an access to a very far headquarters and also to the Internet, thanks to the bidirectional link supported by these satellite systems. DVB-S/RCS systems, mobility protocols and ad-hoc network protocols are first presented separately. The global architecture is then defined. Each kind of architecture is evaluated alone. Finally, architectures performances are compared to each other and the results are discussed as a conclusion.
International audience ; In military or emergency scenarios (like Disaster Relief), the area where the terrestrial forces are located is not always easy to cover. In such an area, no infrastructure is available (never deployed or unavailable due to disaster for instance), persons are located in many locations, eventually structured in groups, but distant from one to another. The topology may also introduce difficulties (canyons, mountains, vegetation.). In such scenarios, communications in a group may be done using ad-hoc networks principle, but the communications from one group to another can be compared to the interconnection of ad-hoc networks. We propose in this paper to interconnect these terrestrial ad-hoc networks with a geostationary DVB-RCS system. This satellite network allows us not only to interconnect the groups, but also to provide them with an access to a very far headquarters and also to the Internet, thanks to the bidirectional link supported by these satellite systems. DVB-S/RCS systems, mobility protocols and ad-hoc network protocols are first presented separately. The global architecture is then defined. Each kind of architecture is evaluated alone. Finally, architectures performances are compared to each other and the results are discussed as a conclusion.
International audience ; The smart grid is an important hub of interdisciplinary research where researchers from different areas of science and technology combine their efforts to enhance the traditional electrical power grid. Due to these efforts, the traditional electrical grid is now evolving. The envisioned smart grid will bring social, environmental, ethical, legal and economic benefits. Smart grid systems increasingly involve machine-to-machine communication as well as human-to-human, or simple information retrieval. Thus, the dimensionality of the system is massive. The smart grid is the combination of different technologies, including control system theory, communication networks, pervasive computing , embedded sensing devices, electric vehicles, smart cities, renewable energy sources, Internet of Things, wireless sensor networks, cyber physical systems, and green communication. Due to these diverse activities and significant attention from researchers, education activities in the smart grid area are also growing. The smart grid is designed to replace the traditional electrical power grid. The envisioned smart grid typically consists of three networks: Home Area Networks (HANs), Neighborhood Area Networks (NANs), and Wide Area Networks (WANs). HANs connect the devices within the premises of the consumer and connect smart meters, Plug-in Electric Vehicles (PEVs), and distributed renewable energy sources. NANs connect multiple HANs and communicate the collected information to a network gateway. WANs serve as the communication backbone. Communication technologies play a vital role in the successful operation of smart grid. These communication technologies can be adopted based upon the specific features required by HANs, NANs, and WANs. Both wired and the wireless communication technologies can be used in the smart grid [1]. However, wireless communication technologies are suitable for many smart grid applications due to the continuous development in the wireless research domain. One drawback of wireless communication technologies is the limited availability of radio spectrum. The use of cognitive radio in smart grid communication will be helpful to break the spectrum gridlock through advanced radio design and operating in multiple settings, such as underlay, overlay, and interweave [2]. The smart grid is the combination of diverse sets of facilities and technologies. Thus, the monitoring and control of transmission lines, distribution facilities, energy generation plants, and as well as video monitoring of consumer premises can be conducted through the use of wireless sensor networks [3]–[6]. In remote sites and places where human intervention is not possible, wireless sensor and actuator networks can be useful for the successful smart grid operation [7], [8]. Since wireless sensor networks operate on the Industrial, Scientific, and Medical (ISM) band, the spectrum might get congested due to overlaid deployment of wireless sensor networks in the same premises. Thus, to deal with this spectrum congestion challenge, cognitive radio sensor networks can be used in smart grid environments [9], [10]. The objective of this Special Section in IEEE ACCESS is to showcase the most recent advances in the interdisciplinary research areas encompassing the smart grid. This Special Section brings together researchers from diverse fields and specializations, such as communications engineering, computer science, electrical and electronics engineering, educators, mathematicians and specialists in areas related to smart grids. In this Special Section, we invited researchers from academia, industry, and government to discuss challenging ideas, novel research contributions, demonstration results, and standardization efforts on the smart grid and related areas. This Special Section is a collection of eleven articles. These articles are grouped into the following four areas: (a) Reliability, security, and privacy for smart grid, (b), Demand response management, understanding customer behavior, and social networking applications for smart grid, (c) Smart cities, renewable energy, and green smart grid, and (d) Communication technologies, control and management for the smart grid.
International audience ; The smart grid is an important hub of interdisciplinary research where researchers from different areas of science and technology combine their efforts to enhance the traditional electrical power grid. Due to these efforts, the traditional electrical grid is now evolving. The envisioned smart grid will bring social, environmental, ethical, legal and economic benefits. Smart grid systems increasingly involve machine-to-machine communication as well as human-to-human, or simple information retrieval. Thus, the dimensionality of the system is massive. The smart grid is the combination of different technologies, including control system theory, communication networks, pervasive computing , embedded sensing devices, electric vehicles, smart cities, renewable energy sources, Internet of Things, wireless sensor networks, cyber physical systems, and green communication. Due to these diverse activities and significant attention from researchers, education activities in the smart grid area are also growing. The smart grid is designed to replace the traditional electrical power grid. The envisioned smart grid typically consists of three networks: Home Area Networks (HANs), Neighborhood Area Networks (NANs), and Wide Area Networks (WANs). HANs connect the devices within the premises of the consumer and connect smart meters, Plug-in Electric Vehicles (PEVs), and distributed renewable energy sources. NANs connect multiple HANs and communicate the collected information to a network gateway. WANs serve as the communication backbone. Communication technologies play a vital role in the successful operation of smart grid. These communication technologies can be adopted based upon the specific features required by HANs, NANs, and WANs. Both wired and the wireless communication technologies can be used in the smart grid [1]. However, wireless communication technologies are suitable for many smart grid applications due to the continuous development in the wireless research domain. One drawback of wireless communication technologies is the limited availability of radio spectrum. The use of cognitive radio in smart grid communication will be helpful to break the spectrum gridlock through advanced radio design and operating in multiple settings, such as underlay, overlay, and interweave [2]. The smart grid is the combination of diverse sets of facilities and technologies. Thus, the monitoring and control of transmission lines, distribution facilities, energy generation plants, and as well as video monitoring of consumer premises can be conducted through the use of wireless sensor networks [3]–[6]. In remote sites and places where human intervention is not possible, wireless sensor and actuator networks can be useful for the successful smart grid operation [7], [8]. Since wireless sensor networks operate on the Industrial, Scientific, and Medical (ISM) band, the spectrum might get congested due to overlaid deployment of wireless sensor networks in the same premises. Thus, to deal with this spectrum congestion challenge, cognitive radio sensor networks can be used in smart grid environments [9], [10]. The objective of this Special Section in IEEE ACCESS is to showcase the most recent advances in the interdisciplinary research areas encompassing the smart grid. This Special Section brings together researchers from diverse fields and specializations, such as communications engineering, computer science, electrical and electronics engineering, educators, mathematicians and specialists in areas related to smart grids. In this Special Section, we invited researchers from academia, industry, and government to discuss challenging ideas, novel research contributions, demonstration results, and standardization efforts on the smart grid and related areas. This Special Section is a collection of eleven articles. These articles are grouped into the following four areas: (a) Reliability, security, and privacy for smart grid, (b), Demand response management, understanding customer behavior, and social networking applications for smart grid, (c) Smart cities, renewable energy, and green smart grid, and (d) Communication technologies, control and management for the smart grid.
The ever-growing amount of data available on the Internet can only be handled with appropriate personalization. One of the most popular ways to filter content matching users' interests is collaborative filtering (CF). Yet, CF systems are notoriously resource greedy. Their classical implementation schemes require a substantial increase in the size of the data centers hosting the underlying computations when the number of users and the volume of information to filter increase. This paper explores a novel scheme and presents DeRec, an online cost-effective scalable architecture for CF personalization. In short, DeRec democratizes the recommendation process by enabling content-providers to offer personalized services to their users at a minimal investment cost. DeRec achieves this by combining the manageability of centralized solutions with the scalability of decentralization. DeRec relies on a hybrid architecture consisting of a lightweight back-end manager capable of offloading CPU-intensive recommendation tasks to front-end user browsers. Our extensive evaluation of DeRec on reals workloads conveys its ability to drastically lower the operation costs of a recommendation system while preserving the quality of personalization compared to a classical approach. On average, over all our experiments, DeRec reduces the load on the back-end server by 72% when compared to a centralized alternative.
The ever-growing amount of data available on the Internet can only be handled with appropriate personalization. One of the most popular ways to filter content matching users' interests is collaborative filtering (CF). Yet, CF systems are notoriously resource greedy. Their classical implementation schemes require a substantial increase in the size of the data centers hosting the underlying computations when the number of users and the volume of information to filter increase. This paper explores a novel scheme and presents DeRec, an online cost-effective scalable architecture for CF personalization. In short, DeRec democratizes the recommendation process by enabling content-providers to offer personalized services to their users at a minimal investment cost. DeRec achieves this by combining the manageability of centralized solutions with the scalability of decentralization. DeRec relies on a hybrid architecture consisting of a lightweight back-end manager capable of offloading CPU-intensive recommendation tasks to front-end user browsers. Our extensive evaluation of DeRec on reals workloads conveys its ability to drastically lower the operation costs of a recommendation system while preserving the quality of personalization compared to a classical approach. On average, over all our experiments, DeRec reduces the load on the back-end server by 72% when compared to a centralized alternative.
The ever-growing amount of data available on the Internet can only be handled with appropriate personalization. One of the most popular ways to filter content matching users' interests is collaborative filtering (CF). Yet, CF systems are notoriously resource greedy. Their classical implementation schemes require a substantial increase in the size of the data centers hosting the underlying computations when the number of users and the volume of information to filter increase. This paper explores a novel scheme and presents DeRec, an online cost-effective scalable architecture for CF personalization. In short, DeRec democratizes the recommendation process by enabling content-providers to offer personalized services to their users at a minimal investment cost. DeRec achieves this by combining the manageability of centralized solutions with the scalability of decentralization. DeRec relies on a hybrid architecture consisting of a lightweight back-end manager capable of offloading CPU-intensive recommendation tasks to front-end user browsers. Our extensive evaluation of DeRec on reals workloads conveys its ability to drastically lower the operation costs of a recommendation system while preserving the quality of personalization compared to a classical approach. On average, over all our experiments, DeRec reduces the load on the back-end server by 72% when compared to a centralized alternative.
International audience ; Cities are growing steadily and urban living poses major challenges in our daily lives. In this context,Information and Communication Technologies (ICT) together with local governments and private companies,play a key role for implementing innovative solutions, to make smart cities a reality. In this context, theInternet of Things (IoT) is an enabler for a broad range of applications and services. The IoT goes through alarger and larger set of heterogeneous devices able to join the Internet spread within the cities among thecitizens. It now makes sense to consider the scenario of these heterogeneous devices interconnected to eachother and to exploit their synergy by involving their sensing and actuation resources in the Cloud.Nevertheless, there are still some challenges to face such as: 1) the interoperability among different ICTsystems; 2) a huge amount of data to be processed provided in real-time by the IoT devices deployed inthe smart systems; 3) the significant fragmentation deriving from the multiple IoT architectures andassociated middleware; 4) heterogeneous resources mashup, namely how to orchestrate resources of thevarious Clouds. Concerning the last item, the concept of IoT, with underlying physical objects abstractedaccording to thing-like semantics, seems a valid starting point for the orchestration of the variousresources. In this context, the Cloud concept could play the role to connect the IoT with the Internet of Peoplethrough the Internet of Services, by the means of a horizontal integration of various silos. In this paper, we introduce the concept of the Cloud of Things (CoT), starting from the traditional Cloud computing concept (Section 2). The CoT concept goes beyond the interconnection and hyperlink of things. It is a horizontal integration of different IoT networks silos and the associated cloud computing. Thedevelopment of the convergence of diverse IoT platforms and Clouds goes through implementedabstraction, virtualization and management of things. A precise ...
International audience ; A Wireless Sensor Network (WSN) is composed of small, low cost and low energy consumption devices called sensors. Those sensors are deployed in a monitored area. They capture measurements related to the monitored phenomenon (temperature, humidity.) and send them through a multi-hop routing to a sink node that delivers them to a Base Station for use and decision making. WSN are used in several fields ranging from military applications to civilian ones, for security, home automation and health care. Up to now, most of the works focused on designing routing protocols to address energy consumption issue, fault tolerance and security. In this paper, we address the issue of secure management and interrogation of WSN through Internet mainly. In our work, we designed and implemented a generic approach based on Web Services that builds a standardized interface between a WSN and external networks and applications. Our approach uses a gateway that offers a synthesis of Web Services offered by the WSN assuring its interrogation and management. Furthermore, Authentication, Authorization and Accounting mechanism has been implemented to provide security services and a billing system for WSN interrogation. We designed our architectur as a generic framework. Then, we instantiated it for two use cases. Furthermore, we designed and implemented a Service Oriented routing protocol for WSN.
International audience ; A Wireless Sensor Network (WSN) is composed of small, low cost and low energy consumption devices called sensors. Those sensors are deployed in a monitored area. They capture measurements related to the monitored phenomenon (temperature, humidity.) and send them through a multi-hop routing to a sink node that delivers them to a Base Station for use and decision making. WSN are used in several fields ranging from military applications to civilian ones, for security, home automation and health care. Up to now, most of the works focused on designing routing protocols to address energy consumption issue, fault tolerance and security. In this paper, we address the issue of secure management and interrogation of WSN through Internet mainly. In our work, we designed and implemented a generic approach based on Web Services that builds a standardized interface between a WSN and external networks and applications. Our approach uses a gateway that offers a synthesis of Web Services offered by the WSN assuring its interrogation and management. Furthermore, Authentication, Authorization and Accounting mechanism has been implemented to provide security services and a billing system for WSN interrogation. We designed our architectur as a generic framework. Then, we instantiated it for two use cases. Furthermore, we designed and implemented a Service Oriented routing protocol for WSN.
International audience ; A critical issue for the k-coverage problem in wireless sensor networks is how efficiently deploying sensors to cover an area of interest. In many critical scenarios such as in the military field, ensuring that each point in the monitored area of interest is sufficiently covered can guaranty the effectiveness of intrusion detection for both monitoring and tracking applications. Prior research indicated that Mobile Sensor Networks (MSNs) are capable of acting with great flexibility to enhance and cover holes appeared in certain regions when a sensor died due to limited energy and battery lifetime. In this paper, we consider the use of a strategy based on the collective motion mechanisms to relocate sensors nodes to achieve a higher k-coverage level. Each sensor node is able to compare its current k-coverage level with a predefined threshold so as to react dynamically by enabling a specific mobility behavior with a high priority. Based on this mobility behavior, a sensor node can move towards other sensors in its local neighborhood, and it would then be closer enough to them in order to enhance its k-coverage level and then it participates in achieving a higher k-coverage level for the whole group. Simulation results show the effectiveness of our considered approach in terms of the k-coverage level of 30 % as well as a significant improvement in energy consumption.
This work has been supported by the French government through the UCAJEDI (ANR-15-IDEX-01) and EUR DS4H (ANR-17-EURE-004) Investments in the Future projects, and by Inria associated team EfDyNet. ; International audience ; Software Defined Networking (SDN) and NetworkFunction Virtualization (NFV) are complementary and corecomponents of modernized networks. In this paper, we considerthe problem of reconfiguring Service Function Chains (SFC)with the goal of bringing the network from a sub-optimal toan optimal operational state. We propose optimization modelsbased on themake-before-breakmechanism, in which a new pathis set up before the old one is torn down. Our method takes intoconsideration the chaining requirements of the flows and scaleswell with the number of nodes in the network. We show that,with our approach, the network operational cost defined in termsof both bandwidth and installed network function costs can bereduced and a higher acceptance rate can be achieved, while notinterrupting the flows.
This work has been supported by the French government through the UCAJEDI (ANR-15-IDEX-01) and EUR DS4H (ANR-17-EURE-004) Investments in the Future projects, and by Inria associated team EfDyNet. ; International audience ; Software Defined Networking (SDN) and NetworkFunction Virtualization (NFV) are complementary and corecomponents of modernized networks. In this paper, we considerthe problem of reconfiguring Service Function Chains (SFC)with the goal of bringing the network from a sub-optimal toan optimal operational state. We propose optimization modelsbased on themake-before-breakmechanism, in which a new pathis set up before the old one is torn down. Our method takes intoconsideration the chaining requirements of the flows and scaleswell with the number of nodes in the network. We show that,with our approach, the network operational cost defined in termsof both bandwidth and installed network function costs can bereduced and a higher acceptance rate can be achieved, while notinterrupting the flows.
