scholarly journals MCRA: Multicost Rerouting Algorithm in SDN

2020 ◽  
Vol 24 (6) ◽  
pp. 728-737
Author(s):  
Kuangyu Qin ◽  
Bin Fu ◽  
Peng Chen ◽  
Jianhua Huang ◽  
◽  
...  
Keyword(s):  
Polynomial Time ◽  
Network Performance ◽  
Optimal Solution ◽  
Software Defined Network ◽  
Centralized Control ◽  
Time Simulation ◽  
Data Plane ◽  
Simulation Results ◽  
Approximate Optimal Solution ◽  
Main Factor

A software-defined network (SDN) partitions a network into a control plane and data plane. Utilizing centralized control, an SDN can accurately control the routing of data flow. In the network, links have various costs, such as bandwidth, delay, and hops. However, it is difficult to obtain a multicost optimization path. If online rerouting can be realized under multiple cost, then network performance can be improved. This paper proposes a multicost rerouting algorithm for elephant flow, as the latter is the main factor affecting network traffic. By performing path trimming, the algorithm can obtain the approximate optimal solution of (1+e) in polynomial time. Simulation results show that the proposed algorithm yields good performance.

scholarly journals Dynamic Load Balancing of Software-Defined Networking Based on Genetic-Ant Colony Optimization

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 311 ◽  
Author(s):  
Hai Xue ◽  
Kyung Kim ◽  
Hee Youn
Keyword(s):  
Load Balancing ◽  
Ant Colony Optimization ◽  
Network Performance ◽  
Optimal Path ◽  
Optimal Solution ◽  
Software Defined Networking ◽  
Ant Colony ◽  
Centralized Control ◽  
Trip Time ◽  
Overall Performance

Load Balancing (LB) is one of the most important tasks required to maximize network performance, scalability and robustness. Nowadays, with the emergence of Software-Defined Networking (SDN), LB for SDN has become a very important issue. SDN decouples the control plane from the data forwarding plane to implement centralized control of the whole network. LB assigns the network traffic to the resources in such a way that no one resource is overloaded and therefore the overall performance is maximized. The Ant Colony Optimization (ACO) algorithm has been recognized to be effective for LB of SDN among several existing optimization algorithms. The convergence latency and searching optimal solution are the key criteria of ACO. In this paper, a novel dynamic LB scheme that integrates genetic algorithm (GA) with ACO for further enhancing the performance of SDN is proposed. It capitalizes the merit of fast global search of GA and efficient search of an optimal solution of ACO. Computer simulation results show that the proposed scheme substantially improves the Round Robin and ACO algorithm in terms of the rate of searching optimal path, round trip time, and packet loss rate.

scholarly journals The Deployment of Routing Protocols in Distributed Control Plane of SDN

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhou Jingjing ◽  
Cheng Di ◽  
Wang Weiming ◽  
Jin Rong ◽  
Wu Xiaochun
Keyword(s):  
Distributed Control ◽  
Closed System ◽  
Routing Protocols ◽  
Network Architecture ◽  
Software Defined Network ◽  
Control Plane ◽  
Data Plane ◽  
Simulation Results ◽  
Routing Control ◽  
Programmable Network

Software defined network (SDN) provides a programmable network through decoupling the data plane, control plane, and application plane from the original closed system, thus revolutionizing the existing network architecture to improve the performance and scalability. In this paper, we learned about the distributed characteristics of Kandoo architecture and, meanwhile, improved and optimized Kandoo’s two levels of controllers based on ideological inspiration of RCP (routing control platform). Finally, we analyzed the deployment strategies of BGP and OSPF protocol in a distributed control plane of SDN. The simulation results show that our deployment strategies are superior to the traditional routing strategies.

Introduction to SDN and NFV

2018 ◽  
pp. 1-25
Author(s):  
Himanshu Sahu ◽  
Misha Hungyo
Keyword(s):  
Network Function Virtualization ◽  
Software Defined Network ◽  
Centralized Control ◽  
Control Plane ◽  
Network Function ◽  
Data Plane ◽  
Network Functions ◽  
The Way

Software defined network (SDN) and Network function virtualization (NFV) are the two new networking paradigms changing the way traditional networks work. SDN works on the concept of centralization so that all the decisions related to controlling the networks is done in a centralized place in a centralized manner. To provide a centralized control, SDN decouples the control plane and data from the traditional routing devices to take it in the centralized position. The data plane is still intact with the routing devices, but they now become mere forwarding devices and the decisions are made at the centralized place called the controller. The controller is basically the x86 server that is connected to the forwarding devices and communicates with them for all control decisions such as routing. NFV is based on virtualization of network functions in the form of software running over a high end server. This kind of virtualization helps in easy setup of networks as well as easy migration.

Dynamical Traffic Engineering in Software-Defined Network

2014 ◽  
Vol 610 ◽  
pp. 954-958 ◽  
Author(s):  
Yi Fan Yu ◽  
Yong Li ◽  
De Peng Jin
Keyword(s):  
Linear Programming ◽  
Real Time ◽  
Traffic Engineering ◽  
Network Architecture ◽  
Optimal Solution ◽  
Software Defined Network ◽  
Software Defined Networks ◽  
Control Plane ◽  
Two Stage ◽  
Data Plane

Software-Defined Networks (SDN), as newly proposed network architecture, has a great potential in optimizing network traffics. In SDN, the control plane is separated from the data plane. With the help of the centralized controller, we can gather information of the network in real time. In this work, we propose a practical two-stage approach for traffic engineering that takes advantages of SDN. The approach not only assures every newly injected flow gets a suitable route that does not have too much payload on it, but also schedules the overall flows so that they are distributed more equally in the network. Furthermore, we demonstrate its efficiency in terms of port speed and compared it with port speed under the default routing decision. We also use linear programming to find the optimal solution and compare it with our result.

scholarly journals Optimize the Communication Cost of 5G Internet of Vehicles through Coherent Beamforming Technology

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Lan Wu ◽  
Juan Xu ◽  
Lei Shi ◽  
Yi Shi ◽  
Wenwen Zhou
Keyword(s):  
Network Performance ◽  
Optimal Solution ◽  
Base Station ◽  
Base Stations ◽  
Bandwidth Efficiency ◽  
Long Distance ◽  
Internet Of Vehicles ◽  
The Cost ◽  
The Mathematical Model ◽  
Approximate Optimal Solution

Edge computing, which sinks a large number of complex calculations into edge servers, can effectively meet the requirement of low latency and bandwidth efficiency and can be conducive to the development of the Internet of Vehicles (IoV). However, a large number of edge servers mean a big cost, especially for the 5G scenario in IoV, because of the small coverage of 5G base stations. Fortunately, coherent beamforming (CB) technology enables fast and long-distance transmission, which gives us a possibility to reduce the number of 5G base stations without losing the whole network performance. In this paper, we try to adopt the CB technology on the IoV 5G scenario. We suppose we can arrange roadside nodes for helping transferring tasks of vehicles to the base station based on the CB technology. We first give the mathematical model and prove that it is a NP-hard model that cannot be solved directly. Therefore, we design a heuristic algorithm for an Iterative Coherent Beamforming Node Design (ICBND) algorithm to obtain the approximate optimal solution. Simulation results show that this algorithm can greatly reduce the cost of communication network infrastructure.

scholarly journals MedShard: Electronic Health Record Sharing Using Blockchain Sharding

2021 ◽  
Vol 13 (11) ◽  
pp. 5889
Author(s):  
Faiza Hashim ◽  
Khaled Shuaib ◽  
Farag Sallabi
Keyword(s):  
Healthcare System ◽  
Small Groups ◽  
Network Performance ◽  
Communication Overhead ◽  
Privacy And Security ◽  
Health Records ◽  
Medical Practitioners ◽  
Blockchain Technology ◽  
Simulation Results ◽  
Electronic Health

Electronic health records (EHRs) are important assets of the healthcare system and should be shared among medical practitioners to improve the accuracy and efficiency of diagnosis. Blockchain technology has been investigated and adopted in healthcare as a solution for EHR sharing while preserving privacy and security. Blockchain can revolutionize the healthcare system by providing a decentralized, distributed, immutable, and secure architecture. However, scalability has always been a bottleneck in blockchain networks due to the consensus mechanism and ledger replication to all network participants. Sharding helps address this issue by artificially partitioning the network into small groups termed shards and processing transactions parallelly while running consensus within each shard with a subset of blockchain nodes. Although this technique helps resolve issues related to scalability, cross-shard communication overhead can degrade network performance. This study proposes a transaction-based sharding technique wherein shards are formed on the basis of a patient’s previously visited health entities. Simulation results show that the proposed technique outperforms standard-based healthcare blockchain techniques in terms of the number of appointments processed, consensus latency, and throughput. The proposed technique eliminates cross-shard communication by forming complete shards based on “the need to participate” nodes per patient.

scholarly journals Optimal Decision-Making to Charge Electric Vehicles in Heterogeneous Networks: Stackelberg Game Approach

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 325 ◽  
Author(s):  
Shijun Chen ◽  
Huwei Chen ◽  
Shanhe Jiang
Keyword(s):  
Electric Vehicles ◽  
Heterogeneous Networks ◽  
Demand Uncertainty ◽  
Stackelberg Game ◽  
Optimal Solution ◽  
Stackelberg Equilibrium ◽  
Optimal Decision ◽  
Charging Station ◽  
Simulation Results ◽  
Grid Operators

Electric vehicles (EVs) are designed to improve the efficiency of energy and prevent the environment from being polluted, when they are widely and reasonably used in the transport system. However, due to the feature of EV’s batteries, the charging problem plays an important role in the application of EVs. Fortunately, with the help of advanced technologies, charging stations powered by smart grid operators (SGOs) can easily and conveniently solve the problems and supply charging service to EV users. In this paper, we consider that EVs will be charged by charging station operators (CSOs) in heterogeneous networks (Hetnet), through which they can exchange the information with each other. Considering the trading relationship among EV users, CSOs, and SGOs, we design their own utility functions in Hetnet, where the demand uncertainty is taken into account. In order to maximize the profits, we formulate this charging problem as a four-stage Stackelberg game, through which the optimal strategy is studied and analyzed. In the Stackelberg game model, we theoretically prove and discuss the existence and uniqueness of the Stackelberg equilibrium (SE). Using the proposed iterative algorithm, the optimal solution can be obtained in the optimization problem. The performance of the strategy is shown in the simulation results. It is shown that the simulation results confirm the efficiency of the model in Hetnet.

scholarly journals Benchmarking Quantum Annealing Against “Hard” Instances of the Bipartite Matching Problem

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Daniel Vert ◽  
Renaud Sirdey ◽  
Stéphane Louise
Keyword(s):  
Simulated Annealing ◽  
Polynomial Time ◽  
Optimal Solution ◽  
Quantum Computers ◽  
Quantum Annealing ◽  
Maximum Cardinality ◽  
Matching Problem ◽  
Bipartite Matching ◽  
Wave Device ◽  
D Wave

AbstractThis paper experimentally investigates the behavior of analog quantum computers as commercialized by D-Wave when confronted to instances of the maximum cardinality matching problem which is specifically designed to be hard to solve by means of simulated annealing. We benchmark a D-Wave “Washington” (2X) with 1098 operational qubits on various sizes of such instances and observe that for all but the most trivially small of these it fails to obtain an optimal solution. Thus, our results suggest that quantum annealing, at least as implemented in a D-Wave device, falls in the same pitfalls as simulated annealing and hence provides additional evidences suggesting that there exist polynomial-time problems that such a machine cannot solve efficiently to optimality. Additionally, we investigate the extent to which the qubits interconnection topologies explains these latter experimental results. In particular, we provide evidences that the sparsity of these topologies which, as such, lead to QUBO problems of artificially inflated sizes can partly explain the aforementioned disappointing observations. Therefore, this paper hints that denser interconnection topologies are necessary to unleash the potential of the quantum annealing approach.

Design Optimization of Autoswitch Hydrogen Absorption and Desorption Device Using Metal Hydrides

2017 ◽  
Vol 15 (6) ◽  
Author(s):  
Ceng He ◽  
Yuqi Wang ◽  
Jing Song ◽  
Shanshan Li ◽  
Fusheng Yang ◽  
...  
Keyword(s):  
Metal Hydride ◽  
Cycle Time ◽  
Single Cycle ◽  
Desorption Process ◽  
Operation Conditions ◽  
Time Simulation ◽  
Structure Improvement ◽  
New Type ◽  
Simulation Results ◽  
Desorption Cycle

Abstract Metal hydride is an influential and promising material for hydrogen utilization. Researchers have carried out a large number of studies on hydrogen storage apparatus, and developed a few new devices for its promotion. Unfortunately, for most metal hydride reactors, the hydrogenation and dehydrogenation are two independent processes owing to the different required conditions, which could cause many inconveniences and safety problems to the H2 absorption & desorption cycle with high frequency and intensity. Hence we proposed a new type of autoswitch H2 absorption & desorption device based on the structure improvement, which consists of rotation disc, fixed disc and the reactor. The numerical simulation for H2 absorption/desorption using LaNi5 was accomplished, and the optimizations on both structure and operation conditions were achieved within a certain period of cycle time. Simulation results show when the single cycle time is set to 1600 s, the absorption temperature has to be lower than 45 °C (3 MPa) and pressure higher than 1.28 MPa (20 °C), and the desorption temperature should be higher than 41 °C (0.1 MPa) and pressure lower than 0.48 MPa (80 °C) under the same cycle time. Meanwhile, the effects of reaction finish time, operating temperature and H2 pressure during absorption/desorption process was investigated and simulation data were also fitted to develop the structural optimization. Under the hydrogenation/dehydrogenation conditions of 3 MPa (20 °C)/0.1 MPa (80 °C), the simulation results indicate the optimal initial reacted fraction and total cycle time are 0.07 and 1287 s, respectively. Moreover, both structures of autoswitch device with 4 and 6 openings have been optimized to satisfy the requirement of each stage. The autoswitch H2 absorption & desorption device can realize the automatic switch between hydrogenation and dehydrogenation orderly and controllably, which would provide convenience for the occasions with this demand and show its remarkable value during popularization and application.

scholarly journals Maximization of Energy Efficiency in Wireless ad hoc and Sensor Networks With SERENA

2009 ◽  
Vol 5 (1) ◽  
pp. 33-52 ◽  
Author(s):  
Saoucene Mahfoudh ◽  
Pascale Minet
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Sensor Networks ◽  
Ad Hoc ◽  
Idle State ◽  
Time Simulation ◽  
Simulation Results ◽  
Remaining Time ◽  
Slot Reuse ◽  
Node Energy

In wireless ad hoc and sensor networks, an analysis of the node energy consumption distribution shows that the largest part is due to the time spent in the idle state. This result is at the origin of SERENA, an algorithm to SchEdule RoutEr Nodes Activity. SERENA allows router nodes to sleep, while ensuring end-to-end communication in the wireless network. It is a localized and decentralized algorithm assigning time slots to nodes. Any node stays awake only during its slot and the slots assigned to its neighbors, it sleeps the remaining time. Simulation results show that SERENA enables us to maximize network lifetime while increasing the number of user messages delivered. SERENA is based on a two-hop coloring algorithm, whose complexity in terms of colors and rounds is evaluated. We then quantify the slot reuse. Finally, we show how SERENA improves the node energy consumption distribution and maximizes the energy efficiency of wireless ad hoc and sensor networks. We compare SERENA with classical TDMA and optimized variants such as USAP in wireless ad hoc and sensor networks.

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