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该文根据无线Mesh网络流量呈现树状拓扑汇聚的特点提出基于拓扑分割的信道分配策略。依据无线干扰对不同链路的影响程度,把无线干扰分类为有确定方向的纵向干扰和横向干扰;提出沿着纵向干扰方向逐跳分割网络拓扑算法;提出最少信道隔离纵向干扰和为吞吐量最小的子拓扑增加信道的子拓扑间信道分配策略;提出横向干扰分块的子拓扑内信道使用方法;理论分析子拓扑内的冲突域及网络性能瓶颈,仿真研究子拓扑的吞吐性能及信道分配顺序。仿真结果表明,隔离纵向干扰和增加信道的分配策略能够有效保证和提升网络吞吐量,横向干扰分块的方法优于802.11s中定义的公共信道框架多信道机制。 相似文献
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本文针对面向ITS应用无线Mesh网络分布式多址接入对时间同步的要求,以及实际应用环境对网络同步的制约因素,通过对已有时间同步机制与技术的分析对比,具体研究在缺乏网络外部高精度同步时钟支持条件下,基于物理层参数解析的分布式WMN全网时间同步方法,给出了改进的无线MESH网网络节点时间同步方案,并就方案性能进行了仿真研究。 相似文献
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针对应急通信背景下无线Mesh网络(WMN)中存在的信道干扰和频谱资源利用不充分的问题,该文提出一种改进的离散蝙蝠算法(IDBA)用于求解最优部分重叠信道(POCs)分配方案。该方法采用K-means聚类算法优化网络拓扑,引入樽海鞘群的链式行为提高局部搜索能力,建立以最小化链路加权干扰为目标的线性规划模型来解决流量汇聚情况可能造成的网络瓶颈链路问题。仿真结果表明,在不同网络规模下,相比于其他基于群智能优化算法的信道分配方法,该方法具有较快的收敛速度和较优的搜索能力。此外,该方法能够在节点密集时显著降低网络干扰并保持网络的稳定性。 相似文献
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Peng Cheng Zhaoyang Zhang Guanding Yu Hsiao‐Hwa Chen Peiliang Qiu 《Wireless Communications and Mobile Computing》2009,9(2):155-167
In this paper, a cross‐layer analytical framework is proposed to analyze the throughput and packet delay of a two‐hop wireless link in wireless mesh network (WMN). It considers the adaptive modulation and coding (AMC) process in physical layer and the traffic queuing process in upper layers, taking into account the traffic distribution changes at the output node of each link due to the AMC process therein. Firstly, we model the wireless fading channel and the corresponding AMC process as a finite state Markov chain (FSMC) serving system. Then, a method is proposed to calculate the steady‐state output traffic of each node. Based on this, we derive a modified queuing FSMC model for the relay to gateway link, which consists of a relayed non‐Poisson traffic and an originated Poisson traffic, thus to evaluate the throughput at the mesh gateway. This analytical framework is verified by numerical simulations, and is easy to extend to multi‐hop links. Furthermore, based on the above proposed cross‐layer framework, we consider the problem of optimal power and bandwidth allocation for QoS‐guaranteed services in a two‐hop wireless link, where the total power and bandwidth resources are both sum‐constrained. Secondly, the practical optimal power allocation algorithm and optimal bandwidth allocation algorithm are presented separately. Then, the problem of joint power and bandwidth allocation is analyzed and an iterative algorithm is proposed to solve the problem in a simple way. Finally, numerical simulations are given to evaluate their performances. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Due to the superiority in large bandwidth capacity and flexible resource allocation,orthogonal frequency division multiplexing passive optical network (OFDM-PON) has been recognized as one of the promising candidates for the next generation PON.There are many research works on the system architecture design of OFDM-PON.However,most of these works focused on the techniques of physical structure and signal transmission and less addressed the bandwidth allocation algorithms supporting the new types of system architecture.The bandwidth allocation in OFDM-PON,which is one of the key techniques to enable the access of multi-service,refers to the joint optimization of multi-dimensional resources in time domain,frequency domain and bits.A layered bandwidth allocation algorithm was proposed for multi-service in the enhanced system architecture of OFDM-PON,aiming at the efficient bandwidth resource utilization.Simulation results prove that the proposed bandwidth allocation algorithm outperforms the conventional algorithms without layered transmission significantly in terms of resource utilization and packet delay. 相似文献
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一种公平的EPON动态带宽分配算法 总被引:7,自引:0,他引:7
提出一种EPON上行链路动态带宽分配算法一周期比例DBA。ONU基于多门限周期地上报带宽请求,OLT根据ONU的带宽请求及其合约带宽进行动态带宽分配。当多个ONU竞争系统带宽时,OLT按照ONU合约带宽的比例进行带宽分配。仿真结果表明:周期比例DBA算法在实现高带宽利用率的同时又具有良好的公平性。 相似文献
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Ethernet Passive Optical Network (EPON) has been widely considered as a promising technology for implementing the FTTx solutions to the “last mile” bandwidth bottleneck problem. Bandwidth allocation is one of the critical issues in the design of EPON systems. In an EPON system, multiple optical network units (ONUs) share a common upstream channel for data transmission. To efficiently utilize the limited bandwidth of the upstream channel, an EPON system must dynamically allocate the upstream bandwidth among multiple ONUs based on the instantaneous bandwidth demands and quality of service requirements of end users. This paper introduces the fundamental concepts on EPONs, discusses the major issues related to bandwidth allocation in EPON systems, and presents a survey of the state-of-the-art dynamic bandwidth allocation (DBA) algorithms for EPONs. 相似文献
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Cooperative access among user devices by sharing wireless access bandwidth opens a new paradigm in heterogeneous networks.However,how to stimulate cooperative relay nodes forwarding service data for others and allocating corresponding bandwidth to support it are two key issues in the cooperative access.This paper proposes a Stackelberg game based framework which is benefit participants including relay nodes and client nodes.This framework generalizes the pricing based bandwidth allocation algorithm by the Stackelberg game model,which optimizes the profit of the cooperative relay nodes while guaranteeing the bandwidth requirements of client nodes.We transform the profit maximization problem into a convex problem and solve it using the convex optimization method.The simulation results demonstrate that the proposed framework and corresponding algorithms outperform the bidding weight proportional fairness and fixed value bandwidth allocation ones significantly. 相似文献