Local Communication Networks Research Articles

Community Media in a Pandemic: Facilitating Local Communication, Collective Resilience and Transitions to Virtual Public Life in the U.S.

This article examines how US community media organisations anchored to public, educational and government (PEG) cable channels facilitated community resilience during the 2020 pandemic. We find evidence that they served as active “meso-agents” (institutional actors) in local communication networks. Some 230 completed survey responses and 10 open-ended interviews with PEG staffers demonstrated that access media commonly performed essential functions including official and community communication and teacher training in new virtual platforms; providing news, especially coordinating official information; and providing “contactless community,” with virtual versions of ritual occasions. These creative responses also suggest new ways to address “news deserts” in the US, if chronic problems with spotty broadband, underfunding of PEG services and lack of federal incentives can be addressed.

The effects of Tx./Rx. pointing errors on the performance efficiency of local area optical wireless communication networks

Abstract This study presents the effects of Tx./Rx. pointing errors on the performance efficiency of local area optical wireless communication networks. The received signal power and max Q factor are measured in the presence of vertical-cavity surface-emitting lasers (VCSELs) bias current and modulation current at maximum propagation distance for the wireless network. The signal is enhanced with increasing of bias and modulation peak currents of the VCSEL device. The optimum received power and max. Q factor is also examined at Tx./Rx. the pointing error of 0.1 mrad and propagation reach of 5 km at available bit rates transmission of 10 Gb/s.

Implementasi Jaringan Internet Site To Site VPN Dengan Metode IPSec Pada PT Telkom Akses

Virtual Private Network (VPN) is a local communication network that is connected through a public network, with a private data security network, the closure of data transfer from illegal access and network scalability are the main standards in a Virtual Private Network (VPN). In building a VPN at PT. Telkom access is done using the Internet Protocol Security (IP Sec) method. PT Telkom Akses is engaged in the business of providing construction services and managing network infrastructure. At this time PT Telkom Akses sent company data using email, if using company email could not ensure the security of the data sent. PT Telkom, which has many branch offices, is required to have a fast and stable internet connection for transmitting confidential company data. Looking at the existing problems, there are several things that are obtained including, communication between users is still not optimal. Data transmission from branch offices to the head office or vice versa is still not encrypted, which means that data can be viewed or retrieved by unauthorized persons and company confidentiality can be threatened. So creating a VPN network with the IPSEC method will get a more stable and safer connection, files and folders that can be shared by network members, making it easier for network administrators to manage the network if the distance between sites is constrained and the network is well encrypted and already using authentication to connect between sites.

Community Media in A Pandemic: Facilitating Local Communication, Collective Resilience and Transitions to Virtual Public Life in the U.S.

This article examines how U.S. community media organizations anchored to public, educational and government (PEG) cable channels facilitated community resilience during the 2020 pandemic. We find evidence that they served as active “mesoagents” (institutional actors) in local communication networks. Some 230 completed survey responses and 10 open-ended interviews with PEG staffers demonstrated that access media commonly performed essential functions including official and community communication and teacher training in new virtual platforms; providing news, especially coordinating official information; and providing “contactless community,” with virtual versions of ritual occasions. These creative responses also suggest new ways to address “news deserts” in the U.S., if chronic problems of spotty broadband, underfunding of PEG services, and lack of federal incentives can be addressed.

New Progress in CPK Public Key

The private-key structure of CPK has developed from single-layer and multi-layer to multi-block and composite structure. The scheme structure of CPK has formed as fixed, flexible or disposable types. CPK digital signature forms an identity signature protocol not only for data signature, but also for identity signature. CPK is not only suitable for the authentication requirements of open global communication network and business network, but also suitable for the authentication requirements of closed local communication network and business network. The disposable private-key structure can resist quantum exhaustion.

МОДЕЛЬ НЕОДНОРОДНОЙ ЛОКАЛЬНОЙ СЕТИ СВЯЗИ С ПРОТОКОЛОМ СИНХРОННОГО ВРЕМЕННОГО ДОСТУПА С УЧЕТОМ НАДЕЖНОСТИ ЕЕ ЭЛЕМЕНТОВ

In the article the local communication network, heterogeneous on the intensity of the incoming message flow and the type of messages, with synchronous time access protocol is considered. All communication stations of the considered local network consist of three substations: speech substations, video information substations and data substations. Speech substations form the speech subnet, video information substations form the video information subnet, and data substations form the data subnet. Substations within the same subnet are homogeneous in their activity. A model of the considered local network in discrete time is being carried out, which allows assessing the effect of the failure processes and restoration of substations of network stations and the communication channel on its characteristics. Based on the developed model of the local network, the probability-time characteristics of the considered network are selected and determined.

Microwave Quantum Link between Superconducting Circuits Housed in Spatially Separated Cryogenic Systems.

Superconducting circuits are a strong contender for realizing quantum computing systems and are also successfully used to study quantum optics and hybrid quantum systems. However, their cryogenic operation temperatures and the current lack of coherence-preserving microwave-to-optical conversion solutions have hindered the realization of superconducting quantum networks spanning different cryogenic systems or larger distances. Here, we report the successful operation of a cryogenic waveguide coherently linking transmon qubits located in two dilution refrigerators separated by a physical distance of five meters. We transfer qubit states and generate entanglement on demand with average transfer and target state fidelities of 85.8% and 79.5%, respectively, between the two nodes of this elementary network. Cryogenic microwave links provide an opportunity to scale up systems for quantum computing and create local area superconducting quantum communication networks over length scales of at least tens of meters.

Risk perception, public health interventions, and Covid-19 pandemic control in sub-saharan Africa

Coronavirus disease 2019 (COVID 19) has had serious social, economic, and health effects globally. The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2), which was first announced in December 2019 has resulted in more than 24 million infections. There is paucity of knowledge on the role of risk perception in the adoption of public health interventions needed to control the spread of COVID 19 infections within communities. This was a scoping review and documents how risk perception may be a major challenge for populations to adopt and implement different behavioral changes recommended to curtail the spread COVID- 19 pandemic in sub-Saharan Africa; and seeks to proffer solutions on how the identified challenges can be addressed drawing from lessons learnt from previous epidemics within the region. Database search of Google Scholar, PubMed, Research Gate among others were performed using related keywords to identify relevant journals and lists of primary articles. Culture, religious beliefs and poverty may influence how populations respond to infectious disease outbreaks. Risk strategies that focus only on biomedical approaches to control the COVID-19 pandemic may not mobilize the needed behavioral change. Lessons learnt from HIV and Ebola epidemics showed that involvement of communities could help transform weak adoption of public health measures when measures were framed in the relevant cultural context. An understanding of the factors influencing risk perception is needed to design appropriate risk communication strategies. Community engagement and reliance on local communication networks could promote mutual trust and increase the uptake of public-health interventions.

Classifying Community Organizational Health Communication Networks: Local Health Department Recognition of Public Information-Sharing Partners Across Sectors.

Local health departments (LHDs) operate within complex, multisectoral organizational communication networks. Network composition may affect priorities, processes, and the reach of health information to key stakeholders. This study seeks to elucidate variation in local network structures to examine how different constellations may affect information sharing across audiences. This study analyzes data from a 2016 US survey of 491 metropolitan LHDs and 556 nonmetropolitan LHDs. Researchers first conducted social network analysis of network density, defined as the total number of potential organizations contributing to a jurisdiction's health communication activities. Researchers then conducted logistic regression to compare the relationship between network density and reported health communication activities targeting 3 specific audiences: policy makers, lay publics, and mass media. Three network types emerged on the basis of the number of organizations that contribute to health communication activities, with low-density Minimal networks more common in nonmetropolitan jurisdictions and higher-density Expanded and Robust networks more common in metropolitan jurisdictions. LHDs in Minimal networks were significantly less likely to communicate with policy makers, lay publics, and mass media than their counterparts in higher-density networks (P < .05). LHDs are embedded in organizational communication networks that vary in both the number of communication partners and the types of audiences reached. Examining their own local organizational communication networks may provide insights into LHDs that wish to improve the effectiveness of public health messaging. By adding organizational communication partners and reaching new audiences, LHDs in Minimal networks can expand the reach of messages designed to help policy makers, communities, and individuals promote health and prevent disease.

IoT Device Identification Protocol based on Degraded Flash Memory

Research subject. The article presents a protocol for identifying IoT devices developed by the authors and the results of its testing. Method. Simulation was performed to determine the probabilistic charac-teristics of 8-bit error-correcting codes. The principles of their coding and decoding are considered. Core results. The features of the developed identification protocol when transmitting packets over the transport protocols TCP and UDP are determined. Practical relevance. The application of the devel-oped protocol for identifying network devices of the Internet of things in local and global communication networks is proposed.

Noise-based synchronization of bounded confidence opinion dynamics in heterogeneous time-varying communication networks

A fundamental question that arises in the analysis of the noise-based synchronization of opinion dynamics with bounded confidence (BC) is what opinion structures can be synchronized by noise. In the standard Hegselmann-Krause (HK) model, each agent examines the opinion values of all other agents and then selects neighbors who are appropriate for opinion updating in accordance with the BC scheme. In reality, however, people are more likely to exchange opinions with only a limited set of individuals, resulting in a predetermined local communication network as postulated in the DeGroot model. In this paper, we develop a new model of opinion formation that endows the heterogeneous HK dynamics with a time-varying communication topology, and we investigate its noise-induced synchronization both mathematically and numerically. We show that opinion dynamics in this model are noise-synchronizable if and only if the switching communication graph is uniformly jointly connected. Our rigorous mathematical analysis and simulation experiments demonstrate that connected discourse topology in combination with fair amounts of noise can lead to a quasi-consensus that is inducible from any initial state or any underlying system size. Our findings have profound implications for the design of future strategies of social control and global opinion optimization.

Locally-distributed and globally-decentralized control for hybrid series-parallel microgrids

Hybrid series-parallel microgrid is a new promising structure for integrating low voltage (LV) and remote sources efficiently. DG units are connected in series as a string locally, and the strings supply power in parallel. This paper proposes a locally-distributed and globally-decentralized (LDGD) control for this microgrid. Local DG units are controlled as a consistent string by distributed cooperative control, and global power demand among strings is shared in a decentralized manner. The frequency synchronization and proper power sharing are achieved under both the resistive-inductive and resistive-capacitive loads. Moreover, only local sparse low-bandwidth communication (LBC) networks are employed, which improves the reliability and reduces the communication costs. The overall system stability is analyzed and reasonable ranges of control parameters are given. Finally, the feasibility and effectiveness of the proposed solution are verified by simulation tests.

Design of high-speed 10-Gb/s wired/FSO systems for local area communication networks for maximum reach

This paper presents the numerical simulation studies of upgraded system for single-mode fiber (SMF wired)/free space optics (FSO wireless) under high-speed operation of 10 Gb/s. Further, the maximum reach of the system is analyzed based on various advanced modulation techniques, namely phase frequency shift keying (CPFSK), quadrature amplitude modulation, differential phase-shift keying, frequency shift keying, pulse amplitude modulation and different optical amplifiers, namely erbium-doped fiber amplifier, traveling wave semiconductor optical amplifier and parametric optical amplifier, respectively. The overall system studies are done by optiwave system software through which bit error rate and Q-factor are studied. The trade-off between different all-optical amplifiers and modulation techniques is studied to show the enhancement of upgrading system. The simulation results show that the maximum reach of distance belongs to CPFSK modulation scheme.

Convergence analysis of max-consensus algorithm in probabilistic communication networks with Bernoulli dropouts

ABSTRACTIn the presence of probabilistic communication networks between agents, the convergence analysis of max-consensus algorithm (MCA) is addressed in this paper. It is considered that at each iteration of MCA, all agents share their measurements with adjacent agents via local communication networks which is applicable in many multi-agent systems (MASs). It is assumed that the communication networks have Bernoulli dropouts, i.e. the information exchanged between agents may be lost with Bernoulli distribution. In the proposed method, the information topology of MAS is modelled as a dynamic graph with the Bernoulli adjacency matrix. It is proved that in the presence of Bernoulli dropouts and under non-restrictive assumptions concerning the MAS features and communication topology, the MCA converges with a probability one in the finite time. Furthermore, the upper bounds are provided by means of deterministic and probabilistic expressions for the expectation and dispersion of convergence time, respectively. It is shown that the proposed upper bounds are asymptotic, i.e. there are specific conditions of MAS in which the convergence time of MCA tends to the proposed upper bounds. The convergence accuracy of MCA is discussed in terms of probabilistic equations. The validity of the proposed theorems is illustrated by means of simulation results.

High-Speed Light Sources in High-Speed Optical Passive Local Area Communication Networks

Abstract This study outlines the high-speed light sources in high-speed passive optical local area communication networks. Directly modulated laser measured is selected as a light source for data rate transfer of 40 Gb/s for propagation range up to 20 km. Optical output power after fiber-optic cable is measured. Signal power amplitude, Q-factor, and data error rates after the receive side are also measured. Hybrid optical amplifier, optical filters, and electrical filters are used for upgrading the network performance operation efficiency. The study assured that the optical communication network can be extended to 20 km distance with data rates of 40 Gb/s with achieving maximum Q-factor of 14.98 and minimum data rates of 3.55 ×10–51.

Digital transformation of learning environment: aspect of cognitive activity of students

Peculiar features of digital environment include: integration of ICTs; use of local and global networks and resources; support and development of qualitatively new technologies of information processing; active use of modern means, methods and forms of teaching in the educational process. The organization of activities in terms of digital learning environment provides appropriate changes in the interaction between subjects of the educational process.Today, means and technologies of the information and communication networks (ICNs), in particular the Internet, which custom and operational-procedural properties were changed at the initial stage from closed local to open ones at present, become widespread. The development of ICNs (from closed local to open ones) changes the typology of learning environments. The following models of learning environments, which widely use ICT and ICN tools (with basic features that characterize them) are distinguished: using the local communication network for presentation of educational information; using the local communication network and open network resources; using open network resources; for independent use of open network resources directly in the classroom by a student; for use of open network resources by a student in the process of independent learning activity; for use by a student educational resources, specially created by a teacher, as well as resources of an open networks in his independent learning activity.

Performance analysis of a GI/D- $$MSP/1/\infty$$ M S P / 1 / ∞ queueing system under different service phase initiations

The main objective of this paper is to derive some analytic results concerning GI/D- $$MSP/1/\infty$$ queueing model in which customers arrive according to a discrete-time renewal process. We assume that the service process is correlated and its configuration is designed through discrete-time Markovian service process under different service phase initiations to start a busy period. The system-length distributions at various time epochs have been obtained by employing the matrix-geometric approach. An explicit closed form expression for the waiting-time distribution in the queue measured in slots has also been derived. Computational experiences with a variety of numerical results are discussed to show the effect of system parameters on the performance measures. This queueing model has potential applications in the domain of computer networks, telecommunication systems, and wireless local communication networks for evaluating the various system performances. An application of this type of queueing model in the domain of network coding in wireless communications is also discussed. This provides relevant information to the system analysts, researchers, and industry people who are interested to investigate congestion problems using queueing theory.

Novel Distributed Optimal Control of Battery Energy Storage System in an Islanded Microgrid with Fast Frequency Recovery

Highly intermittent renewable energy sources pose new challenges to microgrid operation and control. Thus, many distributed control strategies have been proposed to solve this problem. However, for most previous studies, the system frequency fluctuation can be further controlled on the basis of the optimal control strategy. This paper proposes a novel distributed optimal control strategy of a battery energy storage system in an islanded microgrid to provide desired optimal control performance and fast frequency recovery. The proposed control strategy is implemented through a multi-agent system based on consensus algorithm, which only requires information collected through a local communication network. Furthermore, the measurement of supply–demand mismatch is replaced by the control signal obtained from a supplementary controller with the improved linear active disturbance rejection control algorithm. The stability of microgrid frequency can be greatly enhanced through this improvement. Finally, the validity of proposed method is demonstrated by various case studies which are given in this paper.

Data Processing Method in Medium Range Coastal Radar Complex

The article presents the basic principles of design and development of integrated middle range Coastal Surveillance System (CSS) used for water surface lookout. It provides solutions for such missions as command and control of maritime forces, border monitoring and control, prevention of illegal activities such as piracy, smuggling, illegal immigration, illegal fishing, supporting search and rescue (SAR) operations, and creates a common situation awareness picture of the Naval Theatre. The system structure diagram is designed to solve computational overload problem when processing large volume of data received from radar stations. The measurement-level fusion algorithm is developed based on the JPDA framework, in which radar data received from a single or group of radars and AIS data is aggregated in a processing center. The servers and workstations make use of local area network (LAN), using standard Gigabit Ethernet technologies for local network communications. Acquisition, analysis, storage and distribution of target data is executed in servers, then the data is sent to automated operator stations (console), where functional operations for managing, identifying and displaying of target on digital situational map are performed.

Networking for women’s rights: academic centers, regional information networks, and feminist advocacy in southern Africa

ABSTRACTWomen’s rights advocates, in southern Africa as elsewhere, have challenged gender inequality to advance the status of women in society and as a means to also address related, cumulative issues of disadvantage. As communication technologies and neoliberal globalization alter forms of communication, the potential for organizing, coalitions, and advocacy work across time and space, such as through transnational feminist networks (TFNs), has grown. Understanding the rise of TFNs has largely relied on historical narratives and case studies, and the literature has tended to emphasize transnational over regional dimensions. Our approach, however, finds that regional connections not only play an important role in linking TFNs to local women’s rights initiatives in southern Africa, but that information-rich academic institutes focusing on gender studies bring structure to local and regional information networks in the region and act as bridges between the local, regional and global. Methodologically, we employ an innovative approach to visibly capture the work of regional and local activists by taking a meso-level snapshot of website links among 70 women’s rights organizations operating in southern Africa. We pair the network visualization with a case study of our central academic center, the African Gender Institute, to demonstrate the work of this critical hub in the local and regional communication network.