29 research outputs found

    OF-ECF ::a new optimization of the objective function for parent selection in RPL

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    The RPL routing protocol is designed to respond to the requirements of a large range of Low-power and Lossy Networks (LLNs). RPL uses an objective function (OF) to build the route toward a destination based on routing metrics. Considering only a single metric, some network performances can be improved while others may be degraded. In this paper, we present a flexible Objective Function based on Expected Transmission Count (ETX), Consumed Energy and Forwarding Delay (OF-ECF) built on a combination of metrics using an additive method. The main goal of this proposed solution is to balance energy consumption and minimize the average delay. To improve the reliability of the network, a flexible routing scheme that provides the diversity of paths and a higher availability is presented. Simulations results show that the new objective function OF-ECF outperforms the OF-FUZZY, and the standards OF0 and MRHOF. In terms of network lifetime and reliability

    Design and Assessment of an Experimental SDN-Enabled Private Cloud using Openstack

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    Nowadays, educational and research institutions, especially universities, have considered their focus on cloud computing rather than using conventional prospects to take the most benefits of the services offered to support current trends in teaching and learning strategies. To build these networks in a cost effective way, open source cloud computing platforms are used. One of the powerful tools is Openstack, which allows users to create virtual networks and manage virtual machines within distributed learning environments. In this article, we describe our project on designing and evaluating a private cloud within a university environment using Openstack. To this end, we conduct a survey to measure the students’ attitude towards the use of private clouds in which students and experts serve as samples. We design a virtual lab consisting of a number of virtual machines operated by a selected sample. We evaluate the proposed solution by adopting Technology Acceptance Model (TAM) methodology. The results obtained from this study show that the students’ acceptance in using the private cloud in performing their tasks is encouraging albeit their anxiety on security issues and their lack of experience

    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

    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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    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

    A Novel Approach for RPL Assessment Based on the Objective Function and Trickle Optimizations

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    The ROLL working group proposed the RPL (IPv6 routing protocol for low-power and lossy networks) to respond to the requirements of low-power and lossy networks (LLNs). In this paper, we propose a new approach to assess the RPL performances based on its main components, namely, the objective function (OF) and the trickle algorithm. To this end, we compare between the RPL-EC (RPL based combined ETX and energy consumption) and the RPL-FL (RPL based on the flexible trickle algorithm). This paper compares the two implementations to assess the weight of each proposed improvement against the standard RPL. The results show that RPL performances are greatly influenced by the change of both the objective function and trickle algorithm. RPL-FL provides best values in terms of overhead, packet delivery ratio (PDR), and energy consumption, while RPL-EC acts better with the convergence time and the network lifetime compared to the standard RPL

    Service Function Chaining in 5G & Beyond Networks : Challenges and Open Research Issues

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    | openaire: EC/H2020/871780/EU//MonB5GService Function Chaining (SFC) is a trending paradigm, which has helped to introduce unseen flexibility in telecom networks. Network service providers, as well as big network infrastructure providers, are competing to offer personalized services for their customers. Hence, added value services require the invocation of various elementary functions called Service Functions (SFs). The SFC concept composes and imposes the order in which SFs are invoked for a particular service. Emerging technologies such as Software Defined Networking and Network Function Virtualization support the dynamic creation and management of SFC. Even though SFC is an active technical area where several aspects were already standardized and many SFC architecture flavors are currently deployed, yet some challenges and open issues are still to be solved. In this paper, we present different research problems related to SFC and investigate several key challenges that should be addressed to realize more reliable SFC operations.Peer reviewe

    A Novel Compact Header for Traffic Steering in Service Function Chaining

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    | openaire: EC/H2020/723172/EU//5GPagodaLarge-scale networking infrastructures such as service providers deploy complex services to deal with the growing network traffic demand, security concerns, and user preferences. Using Service Function Chaining (SFC) , a set of networking and management operations, permits to steer the traffic through a list of intermediate services. Traffic steering for SFC is usually based on packet headers to share the SFC information, however such headers introduce encapsulation overhead and require service functions support. In this paper, we present a novel traffic steering technique based on a compact SFC header. The proposed header does not increase the packet size and allows network operators to deploy SFC using legacy service functions. We also present a new SDN architecture for SFC based on compact headers. Our proposal permits a scalable and a flexible SFC deployment in real-life infrastructures.Peer reviewe

    VLAN-based Traffic Steering for Hierarchical Service Function Chaining

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    | openaire: EC/H2020/761898/EU//MATILDAAlong the increasing demands for complex networking services, big networking infrastructures, and network service providers aim to provide customized services to the users. Complex services require a composition of intermediate networking Service Functions (SFs). Service Function Chaining (SFC) is a networking concept enabling to compose and force the order of invoking SFs. New technologies such as Software Defined Networking and Network Function Virtualization promote the SFC dynamic composition and management. However, it is still challenging to implement flexible and scalable SF chains in large networking infrastructures. In this paper, we discuss the concept of hierarchical SFC and show its ability to enhance the network scalability and to simplify SFC management. Moreover, we propose a novel traffic steering method to implement hierarchical SFC without requiring data plane components modification. Our proposed approach enhances the scalability of hierarchical SFC and eases its deployment.Peer reviewe
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