Network Operating Research Articles

Business model innovation within SPOs: Exploring the antecedents and mechanisms facilitating multi-level value co-creation within a value-network

To be sustainable, social purpose organisations (SPOs) are increasingly engaging in value networks. This enables them to improve service delivery through social and economic value co-creation (VCC). However, operating within a value network will require SPOs to innovate their business models. This is a complex activity due to their distinctive governance structures and funding arrangements and the need to align value processes across a multiplicity of stakeholders. This paper advances knowledge by exploring how SPOs innovate their business models to engage in VCC through a value-network. By analysing three SPO value networks, we provide new insights into the antecedents and mechanisms of VCC which span the micro, meso, and macro levels of context. We also illustrate the factors which underpin SPOs ability to embed VCC within their business models through operating in a value network.

Türkiye’de ulusal ve yerel sürekli gözlem yapan sabit GNSS istasyonları ağlarının mevcut durumu, standartlar ve farklı ağların entegrasyonu

Turkey's National Permanent GNSS Network-Active (TUSAGA-Active) that has been started to use since 2009 is currently the most widely used geodetic infrastructure element in point positioning in Turkey. In addition to this network operating with the network RTK principle, there are also local Continuously Operating Reference Stations (CORS) networks in our country, which are mainly operated by local governments and a small number of private sector organizations. These networks, which are used nationally and locally, are used effectively in scientific studies as well as in basic engineering works. Integration of local networks in the axis of standards to be defined with the national TUSAGA-Active network is an important issue that should be on the agenda of our country's geodesy community. In this study, CORS networks established at national and local levels in different countries, and examples of the developed standards are given, the current situation in Turkey and contribution of local networks to the scientific studies are discussed. The studies conducted for the comparison of national and local CORS networks were examined, emphasizing the importance of distance between stations in determining the positioning. In this context, the contribution of local networks to the national network has been demonstrated. In this framework, it has been evaluated that shortening the baseline lengths as a result of integration and thus increasing the point density may contribute positively to the network solution quality. However, in order to achieve this development, it is recommended that the development of standards for the design and operation of CORS networks established locally in our country should be addressed with priority.

Bridge and transport network resilience – a perspective

Bridges and critical transport infrastructure are primary assets and systems that underpin human mobility and activities. Loss of bridge functionality has consequences on entire transport networks, which are also interconnected with other networks. Cascading events then unfold in the entire system of systems, leading to significant economic losses and societal disruption to business and society. Recent natural disasters have revealed the vulnerabilities of bridges and critical assets to diverse hazards (e.g. floods, blasts, earthquakes), some of which are exacerbated due to climate change. The assessment of bridge and network vulnerabilities by quantifying their capacity and functionality loss and adaptation to new requirements and stressors is thus of paramount importance. The aim of this work was try to understand the main compound hazards, stressors and threats that have short- and long-term impacts on the structural capacity and functionality of bridges and the impact of bridge closures on network operability. The main drivers of bridge restoration and reinstatement were also considered. Loss of performance, driven by redundancy and robustness of a bridge, is the first step to be considered in the overall process of resilience quantification. Resourcefulness is the other main component of resilience analysed in this work.

Quantum network recovery from multinode failure using network encoding with GHZ states on higher-order butterfly networks

We propose a protocol to transmit three quantum states crossly in a butterfly network with prior entanglement, in the form of GHZ states, between three senders. The proposed protocol requires only one qubit transmission or two classical bits transmission in each channel of the network. We generalize this protocol to higher number of qubits with multiqubit GHZ states towards quantum network operability using network coding with multiqubit GHZ states on higher-order butterfly networks.

Unfairness of Random Access with Collision Avoidance in Industrial Internet of Things Networks.

This paper is focused on the analysis of unfairness of random media access in Local Operating Networks (LON), which is one of the commercial platforms of the Industrial Internet of Things (IIoT). The unfairness in accessing the LON channel is introduced by a collision avoidance mechanism in the predictive p-persistent CSMA protocol adopted at the media access control layer. The study on the bandwidth share in predictive p-persistent CSMA calls for the analysis of multiple memoryless backoff. In this paper, it is shown that the channel access in LON systems is unfair in the short term for medium traffic load conditions, and in the long term for heavy loaded networks. Furthermore, it is explained that the average bandwidth allocated to a particular node is determined implicitly by the load scenario, while an actual node bandwidth fluctuates in time according to stochastic dynamics of the predictive p-persistent CSMA. Next, it is formally proven that the average bandwidth available to a node is a linear function of its backoff state and does not depend on backoff states of the other stations. Finally, it is demonstrated that possibly unfair bandwidth share in LON networks determined implicitly by load scenario is stable because, with lowering a fraction of actual network bandwidth accessible by a given station, the probability to decrease it in the future also drops.

Vulnerability analysis method based on risk assessment for gas transmission capabilities of natural gas pipeline networks

The crucial part of vulnerability analysis is identifying the critical components of a pipeline network. In this study, we proposed a novel analysis method- “Risk-Vulnerability,” which combines the characteristics of risk assessments and vulnerability analyses methods. Risk-Vulnerability identifies the critical components of a pipeline network from three perspectives: pipeline operating status, transmission performance, and network characteristics. The formulas of the importance value of each component were established. Then the component risk indicators were established, and the component risk values were calculated. And a utility theory was introduced to calculate the severity of the consequences. Finally, the component importance and risk values were multiplied to obtain the vulnerability of the component. The feasibility and effectiveness of the method were verified by comparing the identification results of this method to those from the weighted flow capacity rate (WFCR). The Risk-Vulnerability method provides an improved insight into the pipeline criticality compared to the WFCR and improves the calculation formulae based on the identification content, which can not only be used to identify critical components, but also can be used to formulate research on risk reduction measures for pipeline network systems.

Web-Based Toolkit for Performance Simulation and Analysis of Power Line Communication Networks

AMIs (Advanced Metering Infrastructures) present an important role in Smart City environments, especially from the point of view of distribution and customers, offering control and monitoring capabilities. The use of PLC (Power Line Communication) technology offers a wide range of advantages in AMI, including not needing to deploy an additional communication infrastructure. However, the electrical network was not initially designed for communications, as these networks pose problems depending on the connected loads, such as network impedance variation, frequency selectivity or noise. For this reason, the use of simulators is proposed to facilitate the deployments based on PLC networks, and analysis and diagnosis tools for the identification of problems in operating networks are also required. This paper presents a toolkit for evaluating and analyzing the performance of PLC networks. This toolkit is composed of SimPRIME, a simulator for the evaluation of NB-PLC PRIME (PoweR line Intelligent Metering Evolution) networks’ performance; SimBPL, a simulator for the evaluation of MV-BPL (Broadband Power Line over Medium Voltage) cells’ performance; and PRIME Analytics, a forensics tool that allows diagnosis of communication problems in PRIME operational networks based on traffic traces. The toolkit has been developed throughout several research projects in close collaboration with DSOs (Distribution System Operators) and equipment manufacturers, so they provide solutions to actual problems of these industry key players and have been adapted to facilitate their use. As a result, the tools are accessible through web applications to increase their usability, portability, and scalability. These applications represent the first steps in offering PLC simulation and analysis as a service that could benefit the research community, academia, and industry.

Operation of coupled multi-owner district heating networks via distributed optimization

The growth of district heating and cooling (DHC) networks introduces the possibility of connecting them with neighbouring networks. Coupling networks can save costs by reducing operating hours of peak load or backup boilers, or free up production capacity for network expansion. Optimization-based energy management systems (EMS) already provide operators of individual DHC networks with solutions to the unit commitment and economic dispatch problem. They are especially useful for complex networks with multiple producers and integrated renewable energy sources, where incorporating forecasts is important. Time-dependent constraints and network capacity limitations can easily be considered. For coupled networks, a centralized optimization would provide a minimum with respect to an objective function which can incorporate fuel costs, operational costs and costs for emissions. However, the individual coupled networks are generally owned by different organizations with competing objectives. The centralized solution might not be accepted, as each company aims to optimize its own objective. Additionally, all data has to be shared with a centralized EMS, and it represents a single point of failure. A decentralized EMS may therefore be a better choice in a multi-owner setting. In this article, a novel decentralized EMS is presented that can handle multi-owner structures with cooperative and non-cooperative coupling. Each local EMS solves its own optimization problem, and an iterative Jacobi-style algorithm ensures consensus among the networks. The distributed EMS is compared to a centralized EMS based on a representative real-world example consisting of three coupled district heating networks operated by two companies.

Investigating Multilayer Omega-Type Networks Operating with the Cut-Through Technique under Uniform or Hotspot Traffic Conditions

The continuous increase in the complexity of data networks has motivated the development of more effective Multistage Interconnection Networks (MINs) as important factors in providing higher data transfer rates in various switching divisions. In this paper, semi-layer omega-class networks operating with a cut-through forwarding technique are chosen as test-bed subjects for detailed evaluation, and this network architecture is modelled, inspected, and simulated. The results are examined for relevant singlelayer omega networks operating with cut-through or ‘store and forward’ forwarding techniques. Two series of experiments are carried out: one concerns the case of uniform traffic, while the other is related to hotspot traffic. The results quantify the way in which this network outperforms the corresponding singlelayer network architectures for the same network size and buffer size. Furthermore, the effects of the dimensions of the switch elements and their corresponding reliability on the overall interconnection system are investigated, and the complexity and the relevant cost are examined. The data yielded by this investigation can be valuable to MIN engineers and can allow them to achieve more productive networks with lower overall implementation costs.

Modeling interaction between distribution company and networked microgrids in optimal operation of active distribution network

In this paper, the interaction between energy sellers and buyers in utilizing active distribution networks is modeled with considering two networked and non-networked modes of microgrids (MGs). A retail electricity market is modeled as a bi-level problem. Accordingly, the Distribution Company (DISCO) in the upper level in order to maximize the profit offers an optimal price to MGs. While in the lower level, the MGs to compare the offered prices by DISCO with the prices of MGs generation sources for minimizing the total costs decided to whether to buy from the DISCO or not. As the first contribution of the paper is to consider the networked operation of the MGs under a unique beneficiary of MGs (BMG). As the second contribution, two very important indices reserve and self-adequacy are considered, which are necessary in the problems related to MGs. In this paper, the impact of considering and disregarding two important reserve and self-adequacy indices of MGs on the profit of the DISCO in two different scenarios is investigated. In each scenario, the impact of considering two modes networked and non-networked of MGs on the profit of DISCO is investigated. Simulation results show the efficiency the presented model.

New Puppets in the Old School: The Applicability of Traditional Internationalisation Theories in the Sharing Economy

Sharing Economy platforms have expanded their operations all around the globe at an unexpected rate. Due to its “asset-lite” nature, traditional internationalisation theories may not be able to fully explain or predict their expansion patterns. This lack of theoretical background puts at risk the phenomenon’s future and stops traditional companies from coming up with a solid plan to compete against platforms. To ease the creation of a Sharing Economy internationalisation paradigm, this paper intends to review the existing research regarding the internationalisation of sharing platforms as well as the applicability of existing theories. Through a systematic literature review, the existing research was reviewed, and afterwards, internationalisation theories and their distinct factors extracted were noted to address the applicability of these within the singularities of the sharing phenomenon. This classification of factors was done according to the exiting literature in the field. After this research, we can confirm the lack of explanatory power of traditional theories regarding sharing platforms and confirm the insufficient research regarding these operations. We propose a list of factors that should be considered for future research as a guideline for the further development of the Sharing Economy internationalisation theory. Additionally, the factors classification is tested upon the case of the internationalisation of Blablacar, the most extensive carpooling network operating, to check if the theoretical and the practical approaches converge.

Mobile vs. Non-Mobile Live-Streaming: A Comparative Analysis of Users Engagement and Interruption Using Big Data from a Large CDN Perspective

Video streaming on the Internet is constantly changing and growing. New devices and new video delivery mechanisms generate huge gaps in the understanding of how video application works. From exploratory research of one among the largest streaming services in Brazil, this work presents a comparison between mobile and non-mobile users, in large-scale lives. This work focuses on metrics such as engagement, interruption, churn, and payload. This work also presents a report-overview of mobile-users, considering the operating system, geolocation, network access, interruption, and engagement. These results might offer potential information for streaming improvement, in addition to serving as a historical mark.

Routing Performance Evaluation of a Multi-Domain Hybrid SDN for Its Implementation in Carrier Grade ISP Networks

Legacy IPv4 networks are strenuous to manage and operate. Network operators are in need of minimizing the capital and operational expenditure of running network infrastructure. The implementation of software-defined networking (SDN) addresses those issues by minimizing the expenditures in the long run. Legacy networks need to integrate with the SDN networks for smooth migration towards the fully functional SDN environment. In this paper, we compare the network performance of the legacy network with the SDN network for IP routing in order to determine the feasibility of the SDN deployment in the Internet Service provider (ISP) network. The simulation of the network is performed in the Mininet test-bed and the network traffic is generated using a distributed Internet traffic generator. An open network operating system is used as a controller for the SDN network, in which the SDN-IP application is used for IP routing. Round trip time, bandwidth, and packet transmission rate from both SDN and legacy networks are first collected and then the comparison is made. We found that SDN-IP performs better in terms of bandwidth and latency as compared to legacy routing. The experimental analysis of interoperability between SDN and legacy networks shows that SDN implementation in a production level carrier-grade ISP network is viable and progressive.

Spoofing-jamming attack based on cross-technology communication for wireless networks

Cross-Technology Communication(CTC) enables that WiFi devices can talk to ZigBee devices directly without any hardware changes or gateway equipment, and WiFi occupies a much wider bandwidth (20MHz) than ZigBee (2MHz), which sheds the light on spoofing-jamming attack based on CTC, where a WiFi device, as a sophisticated attacker spoofs or jams an area in which multiple-channels sensor network operating. In this work, we attempt to emulate two ZigBee frames under different frequencies within a single WiFi frame by controlling non-continuous bands of subcarriers. In other words, a WiFi device can independently communicate with the ZigBee devices operating in two channels. In a different perspective, the application based on CTC will be significantly impaired when CTC suffers from malicious attacks such as spoofing or jamming. In our work, we implement a parallel spoofing system, called SamBee, that can spoof the ZigBee devices operating in two different channels or jam the ZigBee devices operating in five distinct channels simultaneously only using a single WiFi frame, which causes maximum damage to the network in term of corrupted communication links with low cost. We implement our design based on a USRP-N210 and MICAz hybrid platform, the results show that parallel spoofing attacks and multiple-channels jamming attacks based on CTC is feasible, and our results also provide valuable insights about the associated defense mechanisms on achieving desirable performance.

Opening up ROADMs: streaming telemetry [Invited

We present an implementation of streaming telemetry of optical metrics within open hardware reconfigurable add/drop multiplexers (ROADMs). Our key achievements are sub-second updates of high-resolution spectrum scans, and we demonstrate a sustained telemetry stream of the full C-band with a sub-GHz resolution. The telemetry streaming is implemented over a standard, Internet Engineering Task Force (IETF)-defined protocol (YANG Push) in collaboration with an open-source YANG software stack and device-specific code. As the telemetry collector, we used a common time series database (TSDB) along with a visualization dashboard. We also extended the Open Network Operating System (ONOS) software-defined network (SDN) controller to act as a telemetry receiver.

ARES: A Framework for Management of Aging and Rejuvenation in Softwarized Networks

The recent trend of network softwarization suggests a radical shift in the implementation of traditional network intelligence. In Software Defined Networking (SDN), for instance, the control plane functions of forwarding devices are outsourced to the controller. Softwarized network components are expected to provide uninterrupted service during long periods of time, which makes them prone to the effects of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">software aging</i> , a phenomena that has been observed in operational software systems where the failure rate increases or the performance of the software degrades with the elapsed time since the last restart. The effects of software aging in operational networks are typically mitigated by <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">software rejuvenation</i> , i.e., planned restarts cleaning the internal system state in order to prevent or postpone aging-related failures. This article presents <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ARES</i> , a three-step methodological framework for the management of the effects of software aging in softwarized networks, applied to the case study of open source SDN orchestration platforms. Using ARES, we demonstrate that software aging is a systematic problem that cannot be neglected in network orchestration systems. It stems not only from aging-related bugs and natural aging due to fragmentation, but also from design choices, e.g., when implementing distributed systems. Measurements for Open Network Operating System (ONOS) and OpenDaylight (ODL) demonstrate how “simple” and common networking tasks let network performance degrade rapidly and even lead to crashes: for instance, adding and removing 300 intents per second in ONOS significantly increases the response time by 50% per day and depletes the memory at the rate of 18GB per day. Moreover, we demonstrate a first rejuvenation approach that can mitigate the effects of aging in ONOS.

Study on Passenger Flow Assignment Method of Urban Rail Transit Based on Improved Logit Model

With the advantages of small pollution, punctuality, safety and large capacity, urban rail transportation provides good ideas for solving China’s urban transportation problems and gradually becomes an indispensable part of China’s urban public transportation system. According to the current development of urban rail transportation, the era of networked operation has arrived, and the connectivity between different stations in the metro network and the mobility of operation and management have greatly increased. And for passengers, considering the convenience of seamless transfers, the complexity of the line network structure, and the rapid feedback of real-time passenger flow information on the line, it will cause the passengers’ travel behavior to be highly random. Different passengers are choosing the route selection scheme to reach the target station will also make the spatial and temporal distribution within the rail transit network more diverse and complicated. This paper adopts the method of analyzing the behavior of passenger travel route selection under the established urban rail transit network to establish a generalized cost function and Logit model, and contributes to the planning, design and operation management of urban rail transit.

Digital Control of Electric Power Flows in Unbalanced Distribution Networks as Part of The Automated Metering and Control System

This paper aims to address the problem of controlling the electricity flows in power distribution networks (PDN) operating under current and voltage unbalance. As is known, the unbalance factor is responsible for significant losses of active power and, therefore, is detrimental to the PDN efficiency and technical and economic performance. The purpose of control is to minimize technical power losses in the distribution network. This is to be achieved by building an information control system (ICS) for balancing a three-phase network as part of the automated metering and control system (AMCS). The latter is currently being widely adopted to automate information processes in PDNs. However, the AMCS does not include technologies for solving the problem in question. We propose an algorithm of the digital controller operation for the ICS. Its primary function is to maintain phase power at a given level in real-time. The algorithm concept is based on the idea of required redistribution of electricity flows between the phases of the distribution network by appropriately switching single-phase loads of consumers (users) to ensure a minimum spread of phase powers relative to their required level. To achieve the goal of control, we construct criterion functions that determine qualitative indices of the ICS operation and develop computational schemes for their minimization. Control actions to be generated by the digital controller and performed on the facility represent a digital code that contains data on the coordinates of three-phase network loads to be switched to another phase.

PELATIHAN MEMBUAT VPN MENGGUNAKAN LAYANAN CLOUD COMPUTING SMK MA’ARIF NU 1 KEMBARAN, BANYUMAS

Cloud computing is a technology that has powerful computing resources that can be applied to many organizations by using dynamic scalability as a virtual service source via the internet. SMK Ma'arif NU 1 Kembaran has a 2013 TKJ curriculum. The curriculum has topics such as Computer Assembly, Network Operating Systems and Server Administration. In the subject of Network Operating Systems, there is no subject that discusses cloud computing technology. This technology will have an impact on the average score of students before training to make VPN with cloud computing, namely 83, 12 and after training to 89.06 so that there is a descriptive increase. The hypothesis used is a two-way hypothesis so that it uses two tails with the result t table that is 2.039513 with a p value of 0.01249. Because the p value is smaller than alpha 5% or by looking at the value | t count | &gt; t table then Ho is rejected. This means that there is a significant difference in the level of understanding of students before and after training to make VPN with cloud computing.Cloud computing is a technology that has powerful computing resources that can be applied to many organizations by using dynamic scalability as a virtual service source via the internet. SMK Ma'arif NU 1 Kembaran has a 2013 TKJ curriculum. The curriculum has topics such as Computer Assembly, Network Operating Systems and Server Administration. In the subject of Network Operating Systems, there is no subject that discusses cloud computing technology. This technology will have an impact on the average score of students before training to make VPN with cloud computing, namely 83, 12 and after training to 89.06 so that there is a descriptive increase. The hypothesis used is a two-way hypothesis so that it uses two tails with the result t table that is 2.039513 with a p value of 0.01249. Because the p value is smaller than alpha 5% or by looking at the value | t count | &gt; t table then Ho is rejected. This means that there is a significant difference in the level of understanding of students before and after training to make VPN with cloud computing.

Rain fade margin of terrestrial line-of-sight (LOS) links for 5G networks in Peninsular Malaysia

AbstractAdvanced telecommunication systems are moving toward a high data transfer rate and wider bandwidth. The 5G communication network has recently been implemented for such aims. However, 5G networks operating with high operating frequency (typically above 20 GHz) could lead to impairments because of the atmospheric phenomena mainly precipitation and especially heavy rain. To address this, an optimum rain fade margin for the 5G network in Peninsular Malaysia is proposed using 77 sites of the rain-gauge network, which convert 1-h rain data to 1-min rain data by means of the international telecommunication union recommendation (ITU-R) P.837-7 model. Long-term rain attenuation statistics are obtained from ITU-R P.530-17 and the synthetic storm technique. The predicted rain attenuation is also presented in monthly statistics and in rain attenuation contour maps. The analysis showed that at 99.99% of link availability, the optimum rain fade margin operating at 26 GHz link should be in the range of 6.50 to 10 dB and 7 to 11 dB at 28 GHz link for a 5G network. Such information is useful for network operators and system engineers for the operation of 5G terrestrial microwave links in heavy rain regions.