ISEP – CISTER – Outros
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- On the performance of an air-water visible light communication systemPublication . Martínez, Guillermo; Játiva, Pablo Palacios; Gutiérrez Gaitán, Miguel; Azurdia, Cesar; Boettcher, Nicolás; Zabala-Blanco, DavidResearch on wireless communication in water environments is gaining attention due to its relevance in enabling and supporting new applications under the Underwater Internet of Things (UIoT) umbrella. Visible Light Communication (VLC) is one of the emerging communication technologies with the potential to contribute to this domain, especially concerning direct communications from above the surface to underwater nodes. Although more traditional radio frequency (RF) communications are not suitable for air-to-water communications, VLC offers unique opportunities in this area. In this respect, this work presents a simulative study attempting to theoretically understand the performance of VLC systems in both underwater and air-to-water channels. We explore performance metrics including, link gain, time delay, and bit-error rate, while analyzing the optical signal interruption on the sea surface due to water level changes. The investigation offers preliminary results that shed light on the feasibility and challenges of effectively enabling cross-border air-water communication systems using VLC technologies.
- Evaluation of parental control tools functionalities: The Chilean contextPublication . Rojas, Nicolás; Boettcher, Nicolás; Játiva, Pablo Palacios; Gutiérrez Gaitán, MiguelChoosing a reliable parental control tool is essential to supervising minors accessing information and using electronic devices. For this, it is necessary to determine which tools are the most suitable and if their functionalities are effective. To our knowledge, despite the availability of existing tools that evaluate applications and different actors, e.g., parent control applications recommended by Internet Service Providers (ISPs), none of them properly characterize the various functionalities provided by the application while validating their efficacy. In this paper, we propose a new comprehensive metric to effectively identify and evaluate the functionalities provided by tools in the field of parental control. The metric is applied to some of the most downloaded apps from the Play Store, and the results are compared with the applications recommended by ISPs in Chile, which cover more than 93% of the market. The results from our analysis show that none of the parent control applications recommended by Chilean ISPs managed to provide full confidence in the functionalities implemented since at least one of their functions did not pass the test applied. The end goal for the test metric proposed is to allow future developers to assess their applications beforehand while offering a better match with the customer’s expected service.
- Joint spectrum and antenna selection diversity for V2V links with ground reflectionsPublication . Robles, Ramiro; Gutiérrez Gaitán, Miguel; Javanmardi, Gowhar; Kurunathan, HarrisonThis paper addresses the study of a fading-rejection algorithm based on joint spectrum and antenna selection in a vehicle-to-vehicle (V2V) multiple antenna system. The central objective of this selective scheme is to provide resilience against the destructive effects of the superposition of line-of-sight (LOS) and ground-reflected signals. The paper also provides an extension to channels that combine such deterministic superposition of multiple paths and reflections with an uncorrelated double scattering component, which shows how the algorithm is also beneficial under more general channel modelling assumptions. A multiple-ray performance model is used to describe the deterministic signal interactions between multiple antennas across contiguous vehicles. The antenna selection component is shown to reject deterministic fading, particularly at short values of the inter-vehicular distance. By contrast, when the spectrum bands are correctly chosen, the spectrum selection component can exhibit gains for a wider range of inter-vehicular distances than its antenna selection counterpart. This indicates that both components of the proposed solution are, in some cases, complementary, and therefore, they should be considered together in V2V multiple antenna design. Derivation of the statistics of the selective scheme considering an additional double scattering stochastic channel component is here proposed. Simulation results from all expressions show important gains for a given range of inter-vehicular distances.
- SDN for Dynamic Reservations on Real-Time Networks (Invited Talk)Publication . Almeida, LuisRecent growing frameworks such as the IoT, IIot, Cloud/Fog/Edge computing, CPS, etc, bring the networking platforms on which they rely to the spotlight, as first class citizens of an increasingly software-dependent landscape. As a result, networks play an increasingly central role in supporting the needed system-wide properties. In particular, we have been working to provide openness and adaptivity together with timeliness guarantees. This combination seems fundamental to support inherently dynamic applications in a resource efficient way, covering not only the cases of systems of systems, systems with variable number of users, components or resources but also systems that undergo frequent live maintenance and even reconfiguration during their lifetime. Examples range from autonomous vehicles to collaborative robotics, remote interactions, fog/edge computing, flexible manufacturing, etc. We postulate that combining openess and adaptivity with guaranteed timeliness can only be achieved with an adequate communication abstraction supported on adequate protocols. To this end, we have been proposing channel reservation-based communication as a means to provide scalable and open latency-constrained communication and thus enable a more efficient system design. In this talk we will show our recent work in using Software-Defined Networking (SDN) to provide standard interfaces for traffic flexibility. We proposed extending the SDN OpenFlow protocol with adequate services to take advantage of flexible real-time communication protocols and thus provide standard interfaces for flexible real-time reservations, too. We call it the Real-Time OpenFlow framework (RTOF). We end describing and assessing a prototype implementation based on the HaRTES Ethernet switches.
- System and method for operating a follower vehicle in a vehicle platoonPublication . Li, Zhiwu; Karoui, Oussama; Koubaa, Anis; Khalgui, Mohamed; Guerfala, Emna; Tovar, Eduardo; Wu, NaiqiA method for operating a follower vehicle in a vehicle platoon includes determining, during operation, whether the follower vehicle is operating in a normal state or an abnormal state based on an operation condition of a component of the follower vehicle, or a communication between the follower vehicle and a preceding vehicle in the vehicle platoon. The method further includes selecting a first control mode if the follower vehicle is in the normal state and a second control mode if the follower vehicle is in the abnormal state so as to control movement of the follower vehicle using the selected control mode. In the first control mode, the follower vehicle uses communication data received from the preceding vehicle in the vehicle platoon to control its movement. In the second control mode, the follower vehicle uses data obtained by one or more of its sensors to control its movement.
- Session Summary: Clock IssuesPublication . Gregertsen, Kristoffer Nyborg; Pinho, Luis MiguelThe session was based on a position paper by Kristoffer Nyborg Gregertsen [1], on clock support in Ada. Kristoffer started by providing a brief overview of time and clocks, presenting issues such as resolution, precision, accuracy and drift. The presentation continued with some examples, which led to motivate the need to support high-precision distributed time: - Time synchronized events in distributed control systems; - Sensors with high-precision timestamps for monitoring physical processes; - Applications in robotics, process automation, smart grid applications, etc.
- Session Summary: Parallel ProgrammingPublication . Pinho, Luis MiguelThe session centered on the discussion of three topics, each brought forward by a corresponding submission, backed by distinct participants in the Workshop: 1. Support for parallelism based on OpenMP, championed by Sara Royuela, Eduardo Quinones, and Luis Miguel ˜ Pinho; 2. Synchronous signals, presented by Brad Moore; 3. Heterogeneous platforms, brought forward by Kristoffer Nyborg Gregertsen.
- Guest editorial: real-time networks and systemsPublication . Pinho, Luis Miguel; Faucou, SébastienThis section of Real-Time Systems provides extended journal versions of the outstanding work presented at the 24th International Conference on Real-Time Networks and Systems (RTNS 2016), held at Université de Bretagne Occidentale (November 2016, in Brest, France). The purpose of RTNS is to provide a venue for sharing new ideas, experiences and information among academic researchers, developers and service providers in the field of real-time systems and networks. The 24th edition of the conference continued the established series with a rich program of 34 papers (out of 75 submissions), with a diversity of topics, such as transactions and distributed systems, network analysis, synchronous dataflow graphs, scheduling and schedulability, periodic systems and control, network optimization, many-core and networks-on-chip, multicore scheduling, timing analysis, parallelism, a clear demonstration of the broad scope of real-time systems and networks research. The special issue consists of four papers that cover various areas, from high level system design and optimization to low level timing analysis of computer systems and networks, which have undergone a rigorous peer-review process according to the journal’s high standards.
- Guest Editorial Special Issue on Communications Technologies and Infrastructures for Smart e-Health SystemsPublication . Ullah, Sana; Pedrycz, Witold; Karagiannidis, George K.; Chao, Han-Chieh; Gacek, Adam; Verikoukis, ChristosThe papers in included in this special issue examines new and novel communication methods for smart e-health systems. Recent developments in the healthcare domain have facilitated the integration of several technologies for smart, cost-effective, reliable, and pervasive health monitoring of chronic diseases. Current research efforts focus on developing real-time communication methods, mostly for body area networks (BANs) that are used to deliver patients´ information effectively. These efforts are limited to communication within a BAN; however, less attention has been paid to connect multiple BANs to remote servers in real time. In addition, there is a limited study on the integration of BANs with different technologies including mobile cloud computing—a technology that may assist in storing and processing the huge amount of BAN data at competitive costs. Machine to machine is also considered to be a valuable paradigm in delivering BAN data to a remote server/cloud for further analysis. This may assist in reducing risks and cost of remote health monitoring. Unlike conventional research in BANs where researchers focused on individual networks, there is a need to develop innovative communication methods with a focus on complete and smart e-health systems. This smart e-health system must integrate the aforementioned technologies with multiple BANs, and provide rich healthcare services to end users. It calls for research on versatile topics ranging from physical and medium access control protocols to BANs coexistence, traffic characterization, cloud resource allocation, and cloud monitoring and maintenance.
- Timing Analysis Solutions for Multicore SystemsPublication . Pinho, Luís MiguelA generic framework, integrating models, tools and system software, to parallelize applications with high performance and real-time requirements