Link Resources Research Articles

The Relationship of Delivery Frequency with the Cost and Resource Operational Efficiency: A Case Study of Jingdong Logistics

Under drastic competition, major express companies have increased their daily delivery frequency to improve customer satisfaction and market share. The inverse relationship of frequency with cost and operational efficiency becomes the key to the decision of delivery frequency. This paper uses JD Logistics as an example to quantitatively analyze the relationship mentioned above. The results show that: (1) The cost and resources operational efficiency are closely related to the order splitting ratio under the same delivery frequency; (2) The delivery frequency has different effects on the operational efficiency of the resources in different links. (3) Through the proper splitting and loading of orders, staff scheduling, and area adjustment of delivery station, the optimal delivery frequency can be achieved under the balance of cost and resource operational efficiency. In order to reduce the operating costs of logistics enterprises on the basis of ensuring service levels, one should first properly allocate the amount of orders and splitting ratios to achieve an economic increase in the delivery frequency. In addition, it is important for the logistics enterprises to consider the constraints such as delivery resources and consumer satisfaction to achieve the appropriate decision of delivery frequency. What’s more, it is also crucial to reasonably arrange vehicle loading, staff scheduling and distribution station leasing for the logistics enterprises.

Link Resource Allocation in Counter-Rotating Seam of Low-Orbit Satellite Network

This paper studies the communication problem at the counter-rotating seam of the low-orbit satellite based on the walker constellation. The counter-rotating seam has a short life cycle, low capacity, and dynamic geometric parameters. To better utilize the scarce link resources at the seam, increase network throughput, and approach the physical limits of the link throughput at the seam, an initial phase condition that maximizes the relative rotational joint link throughput is calculated. In the experimental simulation results using the Iridium system as an example, it is shown that better throughput can be obtained under the initial conditions, and the throughput is improved by about 30%.

Virtual Network Embedding Algorithm via Diffusion Wavelet

The great success of the Internet has promoted the development of digital industries and increased the demand for communication bandwidth. For example, ultrahigh-definition videos and vehicle networks require fast bandwidth speed and increase network connection density, respectively. High-bandwidth and high-density parallel communication drive the rapid development of network virtualization and 5G/6G technology. In a network virtualization environment, this new demand also brings new link resource allocation difficulties in existing substrate networks. To solve this far-reaching problem, this paper proposes a virtual network embedding algorithm via diffusion wavelet (VNE_DW), which is an unsupervised structure learning algorithm. Through the diffusion wavelet, the topology structure of nodes, connection density, and link volume among the nodes are comprehensively evaluated. Nodes that facilitate the link mapping success rate are preferentially selected. Experimental results demonstrate that the mapping success rate and revenue-cost ratio of VNE_DW outperform other state-of-the-art algorithms with high bandwidth and density.

On Orchestrating Service Function Chains in 5G Mobile Network

As two of the key technologies of 5G, fog-based radio access network and network function virtualization have become an important direction for the radio network architecture evolution. Virtual network functions (VNFs) compose the service function chain (SFC) in a particular order, and the mobile network users communicate with each other or service terminals through SFCs. For service providers, it is crucially important for efficient deploying/mapping SFCs into the 5G mobile network since the SFCs deployment problem is an NP-hard problem. In this paper, we propose the efficient SFCs deployment algorithms for solving this challenge with two main design goals: 1) minimizing the cost of link resource, i.e., minimizing the path length of the entire SFC by combining VNFs and mapping temporary links and 2) minimizing the cost of computing resources by using the existing virtual machines as much as possible while performing the same VNF. We model the SFCs deployment problem as an optimization problem by using ILP as well as devise the heuristic algorithms to make the tradeoff between these two conflicting design goals. From simulation results, we can see that the performance of our proposed algorithms is promising in terms of the total SFCs mapping cost, total links mapping cost, and blocking ratio.

Survivable Virtual Network Link Shared Protection Method Based on Maximum Spanning Tree

Network virtualization allows multiple independent and mutual non-interfering virtual networks (VNs) to run simultaneously on a shared substrate network (SN) providing a promising method for overcoming the network ossification. Substrate infrastructure failures occur frequently, most of which are substrate link failures. This has created a research hotspot in the field of survivable VN. In this paper, we add to the research by analyzing the substrate link failures and proposing a survivable VN link shared protection method based on the maximum spanning tree. First, an integer linear programming formulation for the survivable VN link shared protection is established to minimize the backup link bandwidth ratio. Second, an efficient VN mapping algorithm based on optimal matching is designed to make full use of the limited substrate resources. This mapping algorithm that fully considers the topological connections between nodes in the node mapping phase improves the acceptance ratio and the long-term average revenue to cost ratio. Finally, a maximum spanning tree link protection algorithm is proposed, and a reasonable sharing mechanism of backup link resources among different VNs is designed to ensure the VN survivability and reduce the SN resource consumption. The experimental results show that our method not only guarantees the VN survivability but also reduces SN resource consumption.

Adaptive Virtual Network Slices for Diverse IoT Services

The next generation communication networks are going to be composed of virtualized node and link resources, which can be divided into various slices. Different virtual network slices can be configured with different amounts of resources so that each slice can be able to optimally satisfy the quality of service requirements of the given category of Internet of Things services. Virtualized resource allocated to slices can be dynamically adjusted to adapt the network capability to varying workload. In this article, we present our ongoing research on autonomous mechanisms for the intelligent allocation and dynamic adjustment of resources to make the virtualized network system scalable while optimally utilizing the resources. We present mechanisms for achieving three types of scalability: vertical scaling by adjusting virtualized resources allocated to a network function within a node, horizontal scaling by adjusting the number of virtualized network nodes and servers, and internetwork scaling by the arbitration of limited resources among many network slices. The preliminary performance evaluation results are also discussed.

Effectively Reconfigure the Optical Circuit Switching Layer Topology in Data Center Network by OCBridge

All optical or hybrid electrical/optical switching data center network (DCN) architectures are capable of adapting the optical-layer topology to various network traffic demands based on the flexibility of optical switching technology. The topology reconfiguration strategies in previous research simply attempt to reconfigure optical circuit switching (OCS) links to offload heavier rack-to-rack traffic. However, due to the complex multi-layer interconnections and the various network traffic patterns in DCNs, the OCS links will not only offload the network traffic between its source and destination racks, but also forward the network traffic that belongs to the adjacent racks of the source and destinations racks. Previous strategies ignore the forwarding traffic and result in sub-optimal solutions. In order to overcome the shortcomings of previous methods and make full use of the OCS link resources in DCNs, an effective topology reconfiguration strategy named optical circuit bridge (OCBridge) has been proposed in our recent work. The main idea of our OCBridge is to take into account the traffic demands between the source and destination regions of each OCS link. In this paper, we first review our OCBridge, and then in simulation, we evaluate the performance of our OCBridge by testing it in two typical OCS-based DCNs, including OpenScale and Helios. Under our OCBridge, we analyze the outstanding network throughput performance of the DCNs and investigate the communication distance of traffic demands. Finally, in experiment, we deploy our OCBridge to a small prototype of OpenScale and verify that our OCBridge is capable of accelerating the distributed computing applications compared with previous topology reconfiguration strategies.

On solving the 1 + 1 routing, wavelength and network coding assignment problem with a bi-objective integer linear programming model

Network coding techniques have been viewed as the promising venue to improve the network efficiency and indeed, have been widely explored in the realm of failure recovery in optical networks. The combination of near-instantaneous recovery achieved by dedicated protections and capacity efficiency enabled by network coding brings about new opportunities to challenge the well-established trade-off of trading speed recovery for capacity efficiency and vice versa. In this context, the use of all-optical XOR network coding has reshaped the traditional 1 + 1 optical path protection in transparent WDM optical networks and established a new problem, called, 1 + 1 routing, wavelength and network coding assignment (1 + 1 RWNCA) as the extension of the conventional 1 + 1 routing and wavelength assignment (1 + 1 RWA). In this paper, we propose a bi-objective integer linear programming model of the 1 + 1 RWNCA problem aiming at minimizing the wavelength resources as the primary objective and simultaneously minimizing the wavelength link usage as the secondary objective. Our formulation uses a weighting method to combine two objectives into an integrated one and we provide insights on setting up the weight vectors to capture the priority of individual objectives. The effectiveness of our integrated objective model in comparison with reference designs based on the single-objective model, 1 + 1 RWA and 1 + 1 RWNCA, is numerically evaluated on different realistic topologies and traffic sets. Extensive simulation highlights that our proposal uses as efficient as around $$60\%$$ of the required wavelength link resources of reference designs and simultaneously achieve the highest performance on the primary objective of minimizing the wavelength resources while its computation time is a few time longer than its single objective counterpart model.

Role of a Measurement Plane to Monitor and Manage QOS in Optical Access Networks

ABSTRACTIn this work, we propose a measurement plane for Software Defined Networking (SDN) architectures for monitoring the network performance and supporting the orchestrator in managing the optical link resources. Concerning the measurement plane, we consider two models that we adopted in other contests: Misurainternet and mPlane. However, due to better scalability, the tests reported in this paper refer to mPlane that has been used in a SDN environment based on Fiber to the X (FTTX) accesses, with procedures of the central unit (orchestrator) that automatically manages GbE links in a regional network. The choices of the orchestrator are based on information received by a reasoner that analyzes the network performance elaborating data detected by active and passive probes. The mPlane-SDN architecture is tested in field measurements concerning FTTX accesses and in Lab to verify the resource allocations in case of traffic congestion. Furthermore, we also show the potentiality of our architecture to evolve toward a distributed controller approach with important advantages for telecom operator strategies.

Dynamic Traffic Scheduling and Congestion Control across Data Centers Based on SDN

Software-defined Networking (SDN) and Data Center Network (DCN) are receiving considerable attention and eliciting widespread interest from both academia and industry. When the traditionally shortest path routing protocol among multiple data centers is used, congestion will frequently occur in the shortest path link, which may severely reduce the quality of network services due to long delay and low throughput. The flexibility and agility of SDN can effectively ameliorate the aforementioned problem. However, the utilization of link resources across data centers is still insufficient, and has not yet been well addressed. In this paper, we focused on this issue and proposed an intelligent approach of real-time processing and dynamic scheduling that could make full use of the network resources. The traffic among the data centers could be classified into different types, and different strategies were proposed for these types of real-time traffic. Considering the prolonged occupation of the bandwidth by malicious flows, we employed the multilevel feedback queue mechanism and proposed an effective congestion control algorithm. Simulation experiments showed that our scheme exhibited the favorable feasibility and demonstrated a better traffic scheduling effect and great improvement in bandwidth utilization across data centers.

An algorithm of virtual network mapping for underwater wireless optical networks

In this paper, a node mapping algorithm, called the radiant node mapping (RNM) algorithm, which is applicable to underwater wireless optical network, is proposed. The RNM algorithm can reduce the distances among mapped nodes, save the resource of links, raise the number of mapped virtual networks, and increase the rate of network utilization. Then, two virtual network embedding algorithms are designed, which are the network mapping algorithm insensitive to the quality of channel (LRC-RNM-QCI) and the network mapping algorithm sensitive to the quality of channel (LRC-RNM-QCS) on the basis of the layered-resource capacity and the RNM algorithm. It is revealed through simulation experiments that both algorithms can significantly improve the success rate of virtual network mapping compared with existing algorithms.

Two level routing method with priority link resource allocation balancing in software defined telecommunication network

Two-level routing method with priority link resource allocation balancing in software defined telecommunication network is proposed. The proposed method is based on the use of a flow-based mathematical model, which allowed providing a coherent solution of routing and link bandwidth allocation. On the other hand, the basis of the proposed method is the interaction prediction principle of the theory of hierarchical multi-level control system, which allowed the introduction of a two-level hierarchy of calculations: the lower level was responsible for calculating routing variables, and the upper level was responsible for the link resource allocation. The numerical example confirms the correspondence of the method to optimal solutions for the finite number of iterations. Also, due to the use of the interaction prediction principle, the solution of the problem of recalculating routes and the order of link resource allocation can be completed on an arbitrary iteration, and the resulting solution will be permissible and meet all the conditions and limitations.

Two-level method of hierarchical-coordination QoS routing based on resource reservation

A method of hierarchical-coordination QoS routing based on network resource reservation is proposed. The proposed method is based on the introduction of a two-level hierarchy of solutions. The lower level was responsible for ensuring a consistent solution of problems of the distributed source routing and reserving the link resource with the provision of end-to-end QoS requirements for the packet rate and average packet delay. The main task of the upper level is overload preventing of communication links during the reservation of their bandwidth initialized in distributed manner by each of the border routers of the network. It is established that the method provides an iterative calculation of the required control variables; the number of such iterations depended on the network structure, the amount of available network resources, the number of flows and their QoS requirements.

A heuristic survivable virtual network mapping algorithm

Network virtualization is a promising solution to attack Internet ossification. Virtual network mapping (or embedding) problem is the core of it and is proved to be NP-hard. In this paper, virtual network mapping problem with survivability is formulated and solved with a heuristic algorithm. Firstly, network link resources are divided into primary flow resources and secondary flow resources. The former are used under normal network operation, whereas the latter are used as backup resources once the networks fail. Secondly, we introduce a novel metric named global resource capacity (GRC) which is recently proposed for measuring node mapping capacity to improve network load balance. At last, a heuristic survivable virtual network embedding algorithm (GRC-SVNE) is proposed. In node mapping phase, we calculate the mapping capacity of all nodes and then some nodes are selected as candidate nodes for virtual network embedding and the goal is to improve mapping successful ratio. After that, link mapping is performed with Dijkstra algorithm. Simulation results show that GRC-SVNE outperforms the traditional greedy algorithm (GREEDY), randomized algorithm (R-ViNE) as well as deterministic algorithm (D-ViNE) and demonstrates desirable results in terms of acceptance ratio, network load balance and network revenue.

Novel Node-Ranking Approach and Multiple Topology Attributes-Based Embedding Algorithm for Single-Domain Virtual Network Embedding

Network virtualization (NV) is a promising approach to remove the ossification of current Internet. Virtual network embedding (VNE) is the key issue in NV which efficiently and effectively maps various of virtual networks (VNs), with different node and link resource requests, onto the shared substrate network(s) with finite underlying resources. Previous VNE algorithms in the literature are mostly heuristic. Single network topology attribute and each node’s local resources are assisted to rank nodes in most heuristic algorithms, leading to inefficient resource utilization of substrate network in the long run. To deal with this issue, we propose the network topology attribute and network resource-considered algorithm (VNE-NTANRC). The VNE-NTANRC algorithm adopts a novel node-ranking approach to rank all substrate and virtual nodes before embedding each given VN. The novel node-ranking approach has two subapproaches and considers five important network topology attributes and global network resources altogether. One subapproach is able to calculate all node values (NoV) directly. The other subapproach, stimulating from the Google PageRank website algorithm, enables to calculate NoVs in a stable state. Simulation results reveal that VNE-NTANRC algorithm outperforms typical and latest heuristic algorithms, only considering single network topology attribute and local resources.

High-efficient full-duplex WDM-RoF system with sub-central station

With an additional sub-central station (S-CS), a high-efficient full-duplex radio-over-fiber (RoF) system compatible with the wavelength-division-multiplexing technology is proposed and experimentally demonstrated in this paper. To improve the dispersion tolerance of the RoF system, the baseband data format for the downlink and an all-optical down-conversion approach for the uplink are employed. In addition, this RoF system can not only make full use of the fiber link resources but also realize the upstream transmission without any local light sources at remote base stations (BSs). A 10-GHz RoF experimental system with a 1.25-Gb/s rate bidirectional transmission is established based on the S-CS structure. The feasibility and reliability of this RoF system are verified through eye diagrams and bit error rate (BER) curves experimentally obtained.

A 2-Layers Virtual Network Mapping Algorithm Based on Node Attribute and Network Simplex

Network virtualization is one of the most important techniques to overcome Internet ossification, which can enable multiple networks to run on a common infrastructure. Virtual network mapping is a key process of network virtualization to efficiently map virtual network onto the substrate network within constraints of node and link resource. However, previous VNM heuristic algorithms completely separate the node mapping stage from link mapping stage and ignore the effect of link mapping results on physical node ranking, which may lead to higher mapping cost and distributed distribution of virtual nodes on the substrate network. The shortest path algorithm is used at most to resolve virtual link mapping which results in longer mapping time. To address these issues, a two-layer virtual network mapping algorithm named simplex-VNM is proposed based on node attribute and network simplex in this paper. In node mapping layer, a new node ranking approach which considers topology attributes, global network resources, and mapped physical node information provides candidate nodes and node mapping cost for link mapping layer. Then, in link mapping layer, network simplex algorithm which has smaller time complexity compared to traditional shortest path algorithms has been introduced to find the optimal link mapping solution under the result of node mapping layer. Finally, according to the results of two layers, the virtual node and relevant links will be mapped with minimal total mapping cost. Extensive simulation results have demonstrated that our proposed method behaves better than four other algorithms that consider node attribute and use shortest path algorithm in terms of total mapping cost and mapping time.

Reliable Virtual Machine Placement Based on Multi-Objective Optimization With Traffic-Aware Algorithm in Industrial Cloud

In a cloud data center, there is usually a large waste of physical resources and link resources, which leads to increased energy consumption. This paper discusses reducing the loss of link resources from the perspective of connectivity between virtual machines. When the virtual machines of a single user request are concentrated to reduce energy consumption, there will be decreased request reliability. This paper considers a single point of failure to ensure the reliability of the requests. Finally, this paper proposes a multi-objective particle swarm optimization algorithm. It takes the physical resource utilization rate and the link loss rate as the optimization targets and uses service reliability and quality of the tenant as constraint conditions. The simulation results show that the method proposed in this paper reliably satisfies the tenant request, effectively controls the link loss in the data center, and significantly reduces the energy consumption of the data center.

Resource approach in studying the role of employees in social partnership: To methodology of research

The article provides a survey of the theoretical ideas of resource approach and the ensuing empirical studies of the role of employees in negotiation with employers and government. The major theorists of resource approach are P. Bourdieu, J. Coleman, N. E. Tihonova, V. I. Il’in, V. V. Radaev, A. N. Krasilova, and V. A. Jadov. R. Putnam and F. Fukuyama’s conception of social capital is an alternative version of resource approach that is used for the analysis of society as a whole. The resource approach is the strategy of scientific research of social inequality in society, based on the analysis of structure and capacity of resources. The resource of the employee is not always required in society or at the labour market. The required resource that determines the status of employee is called “active”. Active converts into capital if it brings the profit due to exceeding the expenses for its reproduction. If the employee has enough capacity of the required social resources, he can realize his interests and influence another subjects of the social partnership. Based on addition of Jadov’s methodology and results of synthesis of empirical studies, we single out three interdependent levels in the structure of social resource: socio-cultural resources, resources of social links and individual-personal resources. Individual-personal resources determine conversion of other social resources into actives and capitals.

Design of a Heuristic Topology Generation Algorithm in Multi-Domain Optical Networks

Designing an excellent original topology not only improves the accuracy of routing, but also improves the restoring rate of failure. In this paper, we propose a new heuristic topology generation algorithm—GA-PODCC (Genetic Algorithm based on the Pareoto Optimality of Delay, Configuration and Consumption), which utilizes a genetic algorithm to optimize the link delay and resource configuration/consumption. The novelty lies in designing the two stages of genetic operation: The first stage is to pick the best population by means of the crossover, mutation, and selection operation; The second stage is to select an excellent individual from the best population. The simulation results show that, using the same number of nodes, GA-PODCC algorithm improves the balance of all the three optimization objectives, maintaining a low level of distortion in topology aggregation.