Hybrid Network Topology Research Articles

A Review of Hybrid VLC/RF Networks: Features, Applications, and Future Directions.

The expectation for communication systems beyond 5G/6G is to provide high reliability, high throughput, low latency, and high energy efficiency services. The integration between systems based on radio frequency (RF) and visible light communication (VLC) promises the design of hybrid systems capable of addressing and largely satisfying these requirements. Hybrid network design enables complementary cooperation without interference between the two technologies, thereby increasing the overall system data rate, improving load balancing, and reducing non-coverage areas. VLC/RF hybrid networks can offer reliable and efficient communication solutions for Internet of Things (IoT) applications such as smart lighting, location-based services, home automation, smart healthcare, and industrial IoT. Therefore, hybrid VLC/RF networks are key technologies for next-generation communication systems. In this paper, a comprehensive state-of-the-art study of hybrid VLC/RF networks is carried out, divided into four areas. First, indoor scenarios are studied considering lighting requirements, hybrid channel models, load balancing, resource allocation, and hybrid network topologies. Second, the characteristics and implementation of these hybrid networks in outdoor scenarios with adverse conditions are analyzed. Third, we address the main applications of hybrid VLC/RF networks in technological, economic, and socio-environmental domains. Finally, we outline the main challenges and future research lines of hybrid VLC/RF networks.

Hybrid Impulsive Pinning Control for Mean Square Synchronization of Uncertain Multi-Link Complex Networks with Stochastic Characteristics and Hybrid Delays

This study explores the synchronization issue for uncertain multi-link complex networks incorporating stochastic characteristics and hybrid delays. Unlike previous works, internal delays, coupling delays, and stochastic delays considered in our model change over time; meanwhile, the impulse strength and position change with time evolution. To actualize network synchronization, a strategy called hybrid impulsive pinning control is applied, which combines the virtue of impulsive control and pinning control as well as two categories of impulses (i.e., synchronization and desynchronization). By decomposing the complicated topological structures into diagonal items and off-diagonal items, multiple nonlinear coupling terms are linearly decomposed in the process of theoretical analysis. Combining inequality technology and matrix decomposition theory, several novel synchronization criteria have been gained to ensure synchronization for the concerning multi-link model. The criteria get in touch with the uncertain strengths, coupling strengths, hybrid impulse strengths, delay sizes, impulsive intervals, and network topologies.

A Dual-Radio Hybrid Mesh Topology for Multi-Hop Industrial IoT Networks in Harsh Environments

Industrial Internet of things (IIoT) is a paradigm that changes the way people interact with infrastructures by enabling ubiquitous connection to the Internet. It allows to design connected infrastructures in industrial environments, e.g., factories, in order to support innovative services and improve efficiency. While the advantages of IIoT are numerous, it has some fundamental issues such as propagation of signal through metallic obstacles, i.e., walls in industrial environments. To address this issue, we propose a hybrid wired-wireless mesh node and network topology called hybrid mesh network (HMN), enabling the signal to cross over the metallic obstacles in harsh environments. The proposed hybrid mesh node utilizes dualradio feature of IEEE 802.11 Wi-Fi standard to improve the performance of the proposed HMN further considering multihop communications. The effects of the packet size and different fading channels on the performance of the proposed HMN are investigated through various simulations. In addition, the performance of the proposed HMN is compared with that of conventional wireless mesh network (WMN). The results reveal that the proposed HMN outperforms conventional WMN and the proposed topology is promising for the implementation of high performance wireless mesh networks in harsh environments.

An Effective Evaluation of Wavelength Scheduling for Various WDM-PON Network Designs with Traffic Protection Provision

Recently, metropolitan and access communication networks have markedly developed by utilizing a variety of technologies. Their bearer communication infrastructures will be mostly exploiting the optical transmission medium where wavelength division multiplexing techniques will play an important role. This contribution discusses the symmetric sharing of common optical network resources in wavelength and time domains. Wavelength-Division Multiplexed Passive Optical Networks (WDM-PON) attract considerable attention regarding the next generation of optical metropolitan and access networks. The main purpose of this contribution is presented by the analysis of possible scheduling of wavelengths for our novel hybrid network topologies considered for WDM-PON networks. This contribution briefly deploys adequate Dynamic Wavelength Allocation (DWA) algorithms for selected WDM-PON network designs with the provision of traffic protection when only passive optical components in remote nodes are utilized. The main part of this study is focused on the use of wavelength scheduling methods for selected WDM-PON network designs. For evaluation of offline and online wavelength scheduling for novel hybrid network topologies, a simulation model realized in the Matlab programming environment allows to analyze interactions between various metropolitan and access parts in the Optical Distribution Network (ODN) related to advanced WDM-PON network designs. Finally, wavelength scheduling methods are compared from a viewpoint of utilization in advanced WDM-PON networks designs.

Energy Efficient Placement of Workloads in Composable Data Center Networks

This paper studies the energy efficiency of composable data center (DC) infrastructures over network topologies. Using a mixed integer linear programming (MILP) model, we compare the performance of disaggregation at rack-scale and pod-scale over selected electrical, optical and hybrid network topologies relative to a traditional DC. Relative to a pod-scale DC, the results show that physical disaggregation at rack-scale is sufficient for optimal efficiency when the optical network topology is adopted, and resource components are allocated in a suitable manner. The optical network topology also enables optimal energy efficiency in composable DCs. The paper also studies logical disaggregation of traditional DC servers over an optical network topology. Relative to physical disaggregation at rack-scale, logical disaggregation of server resources within each rack enables marginal fall in the total DC power consumption (TDPC) due to improved resource demands placement. Hence, an adaptable composable infrastructure that can support both in memory (access) latency sensitive and insensitive workloads is enabled. We also conduct a study of the adoption of micro-service architecture in both traditional and composable DCs. Our results show that increasing the modularity of workloads improves the energy efficiency in traditional DCs, but disproportionate utilization of DC resources persists. A combination of disaggregation and micro-services achieved up to 23% reduction in the TDPC of the traditional DC by enabling optimal resources utilization and energy efficiencies. Finally, we propose a heuristic for energy efficient placement of workloads in composable DCs which replicates the trends produced by the MILP model formulated in this paper.

Soft-Mesh: A Robust Routing Architecture for Hybrid SDN and Wireless Mesh Networks

Wireless Mesh Networks (WMNs) are considered self-organizing, self-healing, and self-configuring networks. Despite these exciting features, WMNs face several routing challenges including scalability, reliability and link failures, mobility, flexibility, and other network management issues. To address these challenges, WMNs need to make programmable to allow modifications of standard techniques to be configured and implemented through software programs that can be resolved by integrating Software Defined Networking (SDN) architecture. SDN, being a cutting-edge technology promises the facilitation of network management as well as routing issues of wireless mesh networks. However, the evolution of the legacy IP-based network model in its entirety leads to technical, operational, and economic problems that can be mitigated by full interoperability between SDN and existing IP devices. This study introduces a Robust Routing Architecture for Hybrid Software-Defined and Wireless Mesh Networks (Soft-Mesh), by systematic and gradual transitioning of WMNs to SDNs in an efficient manner. The main objective of this paper is to suggest improvements to the architecture of the SDN node that allow the implementation of various network functions such as routing, load balancing, network control, and traffic engineering for the hybrid SDN and IP networks. Mininet-WiFi Simulator is used to perform various experiments to evaluate the performance of proposed architecture by creating a hybrid network topology with a varying number of nodes that is 50, 100, 150, 200, and 250 including SDN hybrid and legacy nodes with varying proportion of SDN hybrid and legacy nodes. Results are taken for the average UDP throughput, end-to-end delay, packet drop ratio, and routing overhead while comparing with traditional routing protocols including Optimized Link State Routing (OLSR) and Better Approach to Mobile Adhoc Networking (BATMAN) and with existing hybrid SDN/IP routing architectures including Hakiri and wmSDN. The analysis of simulation results shows that the proposed architecture Soft-Mesh outperforms in terms of the aforementioned performance metrics than the traditional and exiting hybrid routing protocols. Soft-Mesh gives 50% to 70% improved results concerning the incremental proportion of SDN hybrid nodes.

HDDP: Hybrid Domain Discovery Protocol for Heterogeneous Devices in SDN

Computer networks are adopting the new Software-Defined Networking (SDN) architecture, however not all devices can support it, mainly due to power and computational constraints. This letter proposes the Hybrid Domain Discovery Protocol (HDDP), a new discovery protocol that enhances the existing OpenFlow Discovery Protocol (OFDP). HDDP allows the discovery of hybrid network topologies composed of both SDN and non-SDN devices, which no other state-of-the-art protocol can achieve. HDDP has been implemented in a software switch and emulated in diverse networks, where it discovers hybrid topologies by using a number of messages similar to competitors, as they only discover SDN devices.

Networking solutions for connecting bluetooth low energy devices - a comparison

The Bluetooth Low Energy (BLE) is an attractive solution for implementing low-cost, low power consumption, short-range wireless transmission technology and high flexibility wireless products, which working on standard coin-cell batteries for years. The original design of BLE is restricted to star topology networking, which limits network coverage and scalability. In contrast, other competing technologies like Wi-Fi and ZigBee overcome those constraints by supporting different topologies such as the tree and mesh network topologies. This paper presents a part of the researchers’ efforts in designing solutions to enable BLE mesh networks and implements a tree network topology which is not supported in the standard BLE specifications. In addition, it discusses the advantages and drawbacks of the existing BLE network solutions. During analyzing the existing solutions, we highlight currently open issues such as flooding-based and routing-based solutions to allow end-to-end data transmission in a BLE mesh network and connecting BLE devices to the internet to support the Internet of Things (IoT). The approach proposed in this paper combines the default BLE star topology with the flooding based mesh topology to create a new hybrid network topology. The proposed approach can extend the network coverage without using any routing protocol.

Hybrid Flow Architecture for Stable and Scalable Routing in Named Data Networks

<p>The named data network is a new technology in routing were its forwarding plane helps us to recover the data on its own when the network failures occur.in this NDN the major issue are when the data is sent from one network to the other the data flow is not stable. By major survey we came to know that routing protocols plays a major role for the stable and scalable data flow. This routing protocols and be classified by forwarding process and also network topologies were the protocols have the data that can be retrieved back whenever the network faults occur. In this paper we proposed that hybrid flow architecture, network topologies and routing protocols are improved to get the stable and scalable routing when the data flow is interrupted.</p>

철도 차량용 하이브리드 네트워크 토폴로지 최적화 연구

철도 차량용 하이브리드 네트워크 토폴로지 최적화 연구

Four wave mixing power suppression in hybrid network topology using optical phase conjugation module

In this paper, four wave mixing (FWM) power suppression in the case of hybrid network topology is carried out and analyzed. The hybrid network topology consists of bus and ring topologies. In this investigation the optical phase conjugation (OPC) based method is considered as an approach to suppress the FWM power. From the results it is observed that using OPC module the FWM power suppression over 40dBm can be achieved.

Mobile UW-ASN framework with RSSI-based protocol for shallow river monitoring

Approximately three-fourths of our planet’s surface is covered by ocean and seas, a continuous body of water that is divided into several oceans and smaller seas. Water conditions determine climate that affects life on Earth. Whereas fresh water in lakes and rivers covers less 1%, its contamination significantly damages ecosystems. Within this research this paper proposes a framework with a custom protocol stack for river monitoring with hybrid network topology. The main goal is to design and implement a framework of distributed network of navigating autonomous underwater vehicles (AUV) and fixed sensors for rivers that will collect monitoring information and transmit data to the central base station. Proposed framework perfectly fits into the latest notion of internet of underwater things architecture and in future it can be utilised not only for shallow river monitoring but also in such extended applications as pipeline surveillance, harbour security and fish farms monitoring.

Preventing Direct Communication between a Sensor and Sink Node with the Help of Hybrid Network Topology for Energy Conservation in Wireless Sensor Network

Wireless Sensor Networks (WSNs) are paving a way of miniaturization of sensors and actuators by proving a way of boost in the wireless communications by constructing small sized, low power and inexpensive sensor devices that posses high-speed sensing, computational, and communication capabilities. This paper presents the combination of Hybrid Hierarchical Network Topology and Use of different Communication Techniques like Sleep & Wait: Transmission of Data and Low Power Listening: Reception/Listening. This paper proposes a system in which the setup of intermediate nodes (Parent nodes) is done to prevent direct communication between a Sensor and Sink node, which in a nutshell prevents large wait times for transmission.

The Optical Chained-Cubic Tree interconnection network: Topological structure and properties

Interconnection networks with optical communication links outperform others using electronic communication links when the distance is long in terms of speed and power consumption. However, for short distances, electronic network topologies are preferred due to lower material cost requirements. As a result, hybrid network topologies were constructed to combine the benefits of both types of network topologies, such as Optical Transpose Interconnection System (OTIS). This paper presents a new hybrid interconnection network topology, which is constructed using both optical and electronic links, called the Optical Chained-Cubic Tree (OCCT). This new OCCT topology is based on the Chained-Cubic Tree (CCT) interconnection network and is designed to cope with both types of binary trees; full and complete. Also, the topological properties of OCCT in terms of diameter, connectivity, degree, bisection width, and cost are presented and compared with OTIS-Mesh and CCT interconnection networks.

네트워크 이중화를 고려한 IED GOOSE 전송에 관한 성능 분석

In order to prevent loss of communication packets and drop of transmission speed owing to the network fault occurrence, it should be considered network redundancy. That is why a messages of IED GOOSE is the critical signal in charge of protection and control of the substation. So most of users implement the substation automation system with Hybrid network topology ant IED supporting double ethernet ports. Because IEC 61850 GOOSE conformance test is limited in the functional test, this paper suggests how to test the performance of IED GOOSE transmission considering Network redundancy, and describes the analysis of an example test on real IEDs and how to impact the IED GOOSE performance to the substation automation system.

Topological analysis of AOCD-based agent networks and experimental results

Topological analysis of intelligent agent networks provides crucial information about the structure of agent distribution over a network. Performance analysis of agent network topologies helps multi-agent system developers to understand the impact of topology on system efficiency and effectiveness. Appropriate topology analysis enables the adoption of suitable frameworks for specific multi-agent systems. In this paper, we systematically classify agent network topologies and propose a novel hybrid topology for distributed multi-agent systems. We compare the performance of this topology with two other common agent network topologies—centralised and decentralised topologies—within a new multi-agent framework, called Agent-based Open Connectivity for DSS (AOCD). Three major aspects are studied for estimating topology performance, which include (i) transmission time for a set of requests; (ii) waiting time for processing requests; and (iii) memory consumption for storing agent information. We also conduct a set of AOCD topological experiments to compare the performance of hybrid and centralised agent network topologies and illustrate our experimental results in this paper.

Beyond anarchy: Self‐organized topology for peer‐to‐peer networks

AbstractIn this article, we discuss the new constraints that will apply to future, highly dynamic networks and investigate one of the major problems that is likely to affect their deployment: traffic/workload distribution. Starting with a very simple model, we demonstrate that a structure made of undifferentiated subunits will almost inevitably hit a scalability barrier, unless new design rules are applied. We then give quantitative evidence that a hybrid network topology termed the “hypergrid” could have the potential of solving some of the most critical problems (relay overload and network vulnerability), yet could still be produced by applying local rules only. © 2004 Wiley Periodicals, Inc. Complexity 9: 49–53, 2004