24 research outputs found

    Enhancing multi-source content delivery in content-centric networks with fountain coding

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    Fountain coding has been considered as especially suitable for lossy environments, such as wireless networks, as it provides redundancy while reducing coordination overheads between sender(s) and receiver(s). As such it presents beneficial properties for multi-source and/or multicast communication. In this paper we investigate enhancing/increasing multi-source content delivery efficiency in the context of Content-Centric Networking (CCN) with the usage of fountain codes. In particular, we examine whether the combination of fountain coding with the in-network caching capabilities of CCN can further improve performance. We also present an enhancement of CCN's Interest forwarding mechanism that aims at minimizing duplicate transmissions that may occur in a multi-source transmission scenario, where all available content providers and caches with matching (cached) content transmit data packets simultaneously. Our simulations indicate that the use of fountain coding in CCN is a valid approach that further increases network performance compared to traditional schemes

    Information-Centric Connectivity

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    Mobile devices are often presented with multiple connectivity options usually making a selection either randomly or based on load/wireless conditions metrics, as is the case of current offloading schemes. In this paper we claim that link-layer connectivity can be associated with information-availability and in this respect connectivity decisions should be information-aware. This constitutes a next step for the Information-Centric Networking paradigm, realizing the concept of Information-Centric Connectivity (ICCON). We elaborate on different types of information availability and connectivity decisions in the context of ICCON, present specific use cases and discuss emerging opportunities, challenges and technical approaches. We illustrate the potential benefits of ICCON through preliminary simulation and numerical results in an example use case

    Evaluation platform for 5G vehicular communications

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    Cellular vehicle to everything (C-V2X) communications is presented as the cornerstone for next-generation connected vehicles. C-V2X can support efficient vehicle to vehicle and vehicle to infrastructure data transmission, and is said to be a key enabler of cooperative connected and automated mobility (CCAM). Performance of 5G New Radio (5G-NR) is expected to address bandwidth and delay requirements of services for autonomous vehicles. This is the theory and what particular research works have showed through simulation or limited prototypes. On the contrary, this work focuses on evaluating real 5G deployments (including 5G-NR) of network operators in CCAM scenarios, with particular emphasis on cross-border settings and service continuity under inter-operator handovers. The paper presents an evaluation platform to gather cross-layer measurements, homogenise results, perform comparative assessment of figures of merit, and calculate network and CCAM key performance indicators (KPIs). The platform is evaluated through implementing a use case for autonomous overtaking, involving two 5G-NR operator deployments at the Spanish-Portuguese border. Results reveal good network performances and correct operation of the service, thanks to 5G-NR and edge servers, although significant impact of handovers is detected on network and overtaking KPIs.This work has been supported by the grants EC 825496 (5G-MOBIX), funded by the European Commission; PID2020-112675RBC41 (ONOFRE-3), funded by MCIN/AEI/10.13039/ 501100011033; RYC-2017-23823, funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”; PGE-MOVES-SING-2019-000104 (MECANO), funded by the Spanish Ministry for the Ecological Transition and the Demographic Challenge; and RED2018-102585-T (Go2Edge), funded by the Spanish Ministry of Science, Innovation and Universities

    Efficient content delivery through fountain coding in opportunistic information-centric networks

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    Opportunistic networks can increase network capacity, support collaborative downloading of content and offload traffic from a cellular to a cellular-assisted, device-to-device network. They can also support communication and content exchange when the cellular infrastructure is under severe stress and when the network is down or inaccessible. Fountain coding has been considered as espe- cially suitable for lossy networks, providing reliable multicast transport without requiring feedback from receivers. It is also ideal for multi-path and multi- source communication that fits exceptionally well with opportunistic networks. In this paper, we propose a content-centric approach for disseminating con- tent in opportunistic networks efficiently and reliably. Our approach is based on Information-Centric Networking (ICN) and employs fountain coding. When tied together, ICN and fountain coding provide a comprehensive solution that overcomes significant limitations of existing approaches. Extensive network simulations indicate that our approach is viable. Cache hit ratio can be increased by up to five times, while the overall network traffic load is reduced by up to four times compared to content dissemination on top of the standard Named Data Networking architecture

    Correction to: Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

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    Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic. Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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