Coordinated Planning Transmission Tasks in Heterogeneous Space Networks: A Semi-Distributed Approach

This paper studies the coordinated planning of transmission tasks in the heterogeneous space networks to enable efficient sharing of ground stations cross satellite systems. Specifically, we first formulate the coordinated planning problem into a mixed integer liner programming(MILP) problem based on time expanded graph. Then, the problem is transferred and reformulated into a consensus optimization framework which can be solved by satellite systems parallelly. With alternating direction method ...     

Channel Capacity and Power Allocation of MIMO Visible Light Communication System

In this paper, the channel capacity of the multiple-input multiple-output(MIMO) visible light communication(VLC) system is investigated under the peak, average optical and electrical power constraints. Finding the channel capacity of MIMO VLC is shown to be a mixed integer programming problem. To address this open problem, we propose an inexact gradient projection method to find the channel capacity-achieving discrete input distribution and the channel capacity of MIMO VLC. Also we derive both u...     

Dynamic recovery for survivable virtual network embedding

Network virtualization is a promising way to overcome the current ossification of the Intemet. It is essential challenge to find effective, efficient and robust embedding algorithms for recovering virtual network. The virtual network mapping algorithm based on integer programming which was proposed months ago. But it did consider the faults of physical network resources, which is so called survivable virtual network embedding （VNE） problem. Previous strategies for enabling survivability in network virtualization focused on providing protection for the physical network or enhancing the virtual networks by providing backup physical resources in advance, and treated all the physical failures as link failures. In the article, a dynamic recovery method is proposed to solve the survivable virtual network embedding problem based on the integer programming VNE algorithm. The dynamic recovery method doesn＇t need to backup physical resources and it makes more substrate resources which can be used in the embedding. The dynamic recovery process will be activated only when physical failures occur. Different algorithms are used to recovery node and link failures. Simulations show that the method helps to recover almost all of physical failures by finding the substitute nodes and paths, and its performance is very close to that of pure VNE method without considering physical failures.     

Integer Programming Problem Based on Plasmid DNA Computing Model

A DNA algorithm by operating on plasmids was presented to solve a special integer programming, a typical hard computing problem. The DNA algorithm employed double-stranded molecules to encode variables of 0-1 programming problem, the encoded DNA molecules were inserted into circular plasmids as foreign DNA molecules. Followed by, a series of enzymatic treatments to plasmids were performed in order to find feasible solutions to the given problem. The final optimum was obtained by applying founded feasible solutions to object function. Compared with other DNA algorithms of integer programming problem, the proposed algorithm is simple, error-resistant, above all, feasible. Our work clearly showed the distinct advantages of plasmid DNA computing model when solving integer related programming problem.     

Joint power allocation and subcarrier pairing in OFDM-based cooperative relaying system

This paper proposes rate-maximized (MR) joint subcarrier pairing (SP) and power allocation (PA) (MR-SP&PA),a novel scheme for maximizing the weighted sum rate of the orthogonal-frequency-division multiplexing (OFDM) relaying system with a decode-and-forward (DF) relay.MR-SP&PA is based on the joint optimization of both SP and power allocation with total power constraint,and formulated as a mixed integer programming problem in the paper.The programming problem is then transformed to a convex optimization problem by using continuous relaxation,and solved in the Lagrangian dual domain.Simulation results show that MR-SP&PA can maximize the weighted sum rate under total power constraint and outperform equal power allocation (EPA) and proportion power allocation (PCG).     

Cooperative Path Dynamic Planning Model of UCAV Team Based on Global Optimization Method

Cooperative path dynamic planning of a UCAV (unmanned combat air vehicle) team not only considers the capability of task requirement of single UCAV, but also considers the cooperative dynamic connection among members of the UCAV team. A cooperative path dynamic planning model of the UCAV team by applying a global optimization method is discussed in this paper and the corresponding model is built and analyzed. By the example simulation, the reasonable result acquired indicates that the model could meet dynamic planning demand under the circumstance of membership functions. The model is easy to be realized and has good practicability.     

QoS-priority based load balancing algorithm for LTE systems with mixed users

Focusing on the load balancing problem among multi-cells in long term evolution(LTE) networks with mixed users, a new multi-objective optimization modeling strategy, which integrates the guaranteed bit rate(GBR) and the best effort(BE) users, was proposed. In consideration of quality of service(Qo S) priorities of different users, a decomposition method was presented to solve the original model. Derivations such as applying Lagrange multiplier method, sub-optimal solutions for mixed users were deduced. Based on derived solutions, including resource allocation schemes, a practical multi-objective load balancing algorithm jointly dealing with mixed users was given. Simulation shows a significant improvement of GBR users’ satisfaction level and BE users’ throughput in LTE networks by using the proposed algorithm.     

DESIGN OF MULTI—SERVICE SDH NETWORKS：FORMULATION AND HEURISTICS

Multi-service SDH networks support both packet-and circuit-switched traffic.Optimal design of such a network means to guarantee the circuit connections and configure a logical packet-switched topology with lowest congestion.This letter first formulates the problem as a mixed integer linear programming,which achieves optimal solution but has high computation.Then a heuristic algorithm is proposed to yield near-optimal soultion effciently.Performance of the algorithm is verified by an example.     

Concurrent speeches separation using Wrapped Discrete Fourier Transform

This letter proposes a new method for concurrent voiced speech separation. Firstly the Wrapped Discrete Fourier Transform (WDFT) is used to decompose the harmonic spectra of the mixed speeches. Then the individual speech is reconstructed by using the sinusoidal speech model. By taking advantage of the non-uniform frequency resolution of WDFT, harmonic spectra parameters can be estimated and separated accurately. Experimental results on mixed vowels separation show that the proposed method can recover the original speeches effectively.     

Selection of PCEs＇ location in multi-domain optical networks

Path computation elements （PCEs） are employed to compute end-to-end paths across multi-domain optical networks due to the advantages of powerful computation capability. However, PCEs＇ location selection is still an open problem which is closely related to the communication overhead. This paper mainly focuses on the problem of PCEs＇ location selection to minimize the overall communication overhead in the control plane. The problem is formulated as a quadratic integer programming （QIP） model, and an optimal decision rule is gained from the solution of the QIP model. Then based on the decision rule, a distributed heuristic algorithm is proposed for dynamic network scenario. Simulation results demonstrate the benefit and the effectiveness of our proposed approach by comparing it with random selection policy.     

移动WiMAX无线网络规划的流程和方法

WiMAX无线网络规划是当今宽带移动通信领域一个重要的研究课题。本文首先介绍TWiMAXN络结构,接着描述了移动WiMAX无线网络规划的流程,其中详细论述了传播模型校准、链路预算,最后给出了详细规划中频率规划和系统级仿真的过程和方法,为移动WiMAX的大规模建设提供了参考和经验。     

浅谈WiMAX频率规划

简单介绍了WiMAX技术、提高WiMAX频率利用率的方法,并分析了影响WiMAX频率规划的2个因素。     

Highly efficient optical aggregation network with network functions virtualization

Network functions virtualization enables network edge functions to be relocated from dedicated hardware to distributed pools of commodity servers. Metro aggregation networks provide transport between access gateway nodes and such servers accommodating virtual network functions (VNFs). Networks need to be designed to increase the efficiency of network resource usage and reducing network cost as well as energy consumption. However, independently placing VNFs on a server from a physical network design degrades the efficiency of resource usage and causes an increase in network cost. We can avoid such problems by adequately placing each VNF in consideration of the location of access gateway nodes and a network topology. We thus propose a method for designing an optical aggregation network with VNF placement. We successfully formulate the design method as mixed‐integer linear programming and demonstrate its effectiveness through intensive mathematical experiments. The experiments showed that the proposed method reduced network cost by up to about 18% while performing almost optimally in terms of server load dispersion.     

可生存光纤—无线融合宽带接入网规划方法

光纤—无线融合（fiber-wireless,FiWi）宽带接入网的出现不仅为随时随地的灵活宽带接入提供了新的技术参考,同时也为可生存宽带接入网的低成本设计增加了研究契机。研究了可生存FiWi接入网的网络规划问题,提出一种基于无线重路由保护的可生存网络规划方法。当任意光纤链路断裂时,失效的光网络单元可通过无线重路由将业务转移到其他可用的光网络单元承载。重点解决了无线路由器部署、备份射频接口配置及光网络单元容量分配的联合优化问题,目标是通过最小化网络部署成本实现业务的完全保护。采用整数线性规划方法获得了小规模网络规划问题的最优解,同时提出了适用于大规模网络规划问题的启发式算法。仿真结果证实了所提方法在降低网络部署成本方面的有效性。     

Network planning for mobile multi‐hop relay networks

In this paper, the coverage problem of network planning in mobile multi‐hop relay networks is defined on the basis of integer linear programming. In order to provide desired utilities and also meet deployment limitations for network planning, we propose a supergraph tree algorithm to place base stations and relay stations at the lowest cost position. Furthermore, another algorithm for avoiding the interference between base stations, which is called interference aware tree algorithm is also proposed. Both the proposed algorithms are formulated on the basis of a graph theoretic technique and analyzed in the simulation results. The results show that the supergraph tree algorithm provides the lowest construction cost with different network scenarios, and the interference aware tree algorithm provides the highest communication quality for mobile multi‐hop relay infrastructure‐based communication network planning. Copyright © 2013 John Wiley & Sons, Ltd.     

WiMAX组网方案研究

本文研究了基于OFDM技术的WiMAX小区规划方案,给出了各种提高频谱效率的方案;然后对WiMAX与现网的融合进行了分析,给出了紧耦合和松耦合两种方法,并就基于IPv6的WiMAX核心网机制进行了阐述;最后对基站的无线互联方案进行了探讨.     

宽带无线接入WiMAX系统组网设计

WiMAX作为新兴的宽带无线接入技术,具有覆盖范围广、传输带宽大的特点,已经成为电信业关注的热点,WiMAX无线接入系统的组网设计问题已成为一个重要的课题.文中对WiMAX组网设计涉及到的几个关键问题,如业务需求预测、频率规划、传播摸型、组网方式等相关问题进行了探讨,可为WiMAX无线接入网络的规划,工程设计和工程建设提供参考和帮助.     

WiMAX无线网络规划

本文结合WiMAX的技术特性,主要探讨了IEEE802.16d和802.16e无线网络的覆盖、容量和频率规划特点,并分析了WiMAX的系统干扰,为运营商的网络建设提供了参考与建议。     

Cost‐Efficient Virtual Optical Network Embedding for Manageable Inter‐Data‐Center Connectivity

Network virtualization opens the door to novel infrastructure services offering connectivity and node manageability. In this letter, we focus on the cost‐efficient embedding of on‐demand virtual optical network requests for interconnecting geographically distributed data centers. We present a mixed integer linear programming formulation that introduces flexibility in the virtual‐physical node mapping to optimize the usage of the underlying physical resources. Illustrative results show that flexibility in the node mapping can reduce the number of add‐drop ports required to serve the offered demands by 40%.     

Overview of mobile WiMAX technology and evolution

Mobile WiMAX is a fast growing broadband access technology that enables low-cost mobile Internet applications, and realizes the convergence of mobile and fixed broadband access in a single air interface and network architecture. Mobile WiMAX combines OFDMA and advanced MIMO schemes along with flexible bandwidth and fast link adaptation, creating a highly efficient air interface that exceeds the capacity of existing and evolving 3G radio access networks. WiMAX networks, built on all-IP network architecture for plug and play network deployments, can support a mix of different usage and service models. While some consider mobile WiMAX as a candidate for the fourth generation of mobile networks, others view it as the first generation of mobile Internet technologies emerging from a wider ecosystem targeting to extend the success of WiFi over wide area networks supporting mobility. This article provides a high-level overview of mobile WiMAX technology and its evolution roadmap from both radio and network perspectives.