带有卸载时延感知的边缘云增强FiWi网络节能机制

边缘云增强光无线融合网络中,存在传统节能机制与卸载业务不匹配的问题。该文提出一种带有负载转移的光网络单元卸载协同休眠机制。通过分析当前光网络单元负载,结合无线域多跳传输时延和目标光网络单元的报告帧发送时刻,进而确定休眠和目的光网络单元完成负载转移。然后光网络单元协同考虑边缘服务器的回传数据到达时刻和无线域控制帧的发送时刻,选取最合适的休眠时长以减少控制开销。仿真结果表明,所提机制在有效降低网络能耗的同时能保证卸载业务的时延性能。     

带有卸载压缩激励的云增强FiWi网络节能机制

针对云增强型光纤-无线(FiWi)网络能耗以及卸载的通信开销过大问题,该文提出一种自适应卸载压缩节能机制(ESAOC),针对不同类型的业务属性和最大的容忍时延,结合光网络单元的负载变化和无线网状网的流量情况,通过统计的方式获得不同优先级卸载数据的平均到达率,再结合各个节点的压缩时延,动态调整业务的卸载压缩比,以降低卸载的通信开销;同时,建立排队模型分析卸载业务在MEC服务器的排队时延,协同调度无线侧中继节点,进而对光网络单元和终端设备进行协同休眠调度,最大化休眠时长,提高系统能源效率。结果表明,所提方法在有效降低整个网络能耗的同时能够保证卸载业务的时延性能。     

新型无线紫外光协作通信网络性能分析与研究

为进一步提高无线紫外光通信网络的信息传输质量和网络性能,提出了一种新型无线紫外光协作通信网络,网络中各节点采用解码转发方式,设定各节点优先级,从而实现了网络节点实时转发的协作策略。仿真分析了有无缓存设置和有无协作条件下无线紫外光通信网络的归一化吞吐量、各节点平均时延等性能。仿真结果表明：无缓存设置时,随着数据帧传输成功率的增加,高优先级节点一直有较高的归一化吞吐量,而低优先级节点数据帧丢失,归一化吞吐量下降;有缓存设置时,随着缓存的增加,各节点归一化吞吐量均有所增加;与无协作相比,有协作的紫外光通信网络具有更高的节点归一化吞吐量和平均时延。     

长距离CSMA/CA协议的系统设计

文中研究载波监听多路访问/冲突避免(CSMA/CA)接入机制在航空无线自组织网络中的应用。航空无线自组织网络是一种长传播时延的自组织网络,首先对长传播时延背景下的CSMA/CA接入协议进行了理论分析,研究时隙长度(Slot),短帧间间隔(SIFS)和源节点等待ACK包的时间对系统性能的影响。通过分析得到不同传输半径下CSMA/CA的最优参数配置。通过仿真结果表明,长距离CSMA/CA可以基本保持CSMA/CA的吞吐量。     

OBS网络基于光缓存的多优先级业务冲突研究

光突发交换(OBS)网络是下一代IP over WDM光网络的典型代表.丈章时配置有光缓存的OBS网络核心节点中发生的多优先级业务冲突问题进行了性能分析,给出了不同优先级数据包的丢失率和平均等待时延,研究结果可以为OBS网络的实用化提供理论参考.     

基于优先级的OBS核心节点性能研究

设计了基于业务优先级的光突发交换核心节点模型,采用多级光纤延迟线的光缓存来提高交换网络的性能.交换节点在4个端口8条波长(4×8核心交换结构)的情况下,当光纤延迟线基本延迟单元为50μs、级数为8,负载为0.8时,丢包率小于0.01;为了满足不同业务服务质量的要求,将数据包按优先级划分,采用基于优先级的插空算法(VFPP),在相同缓存配置条件下使高优先级数据的丢包率降低到以下,在高负载下平均时延小于不区分优先级的情况.     

TWDM-PON中带有业务区分的混合资源调度算法

针对时分波分复用无源光网络长距离和广覆盖特性带来往返时延增大,造成高优先级业务时延性能严重恶化的问题,提出带有业务区分的混合资源调度算法.根据网络负载实时调整光网络单元组的波长数以实现资源共享,并动态划分子周期以对不同优先级业务进行区分服务;设计混合资源调度算法,以在线方式填充波长空隙,以离线方式保障资源高效调度.仿真结果表明,所提算法能够满足不同优先级业务的时延要求,保证服务质量,并提高信道利用率.     

一种光交换核心节点调度算法研究

光交换核心节点是光交换网络的核心设备,其性能的优劣直接影响网络的吞吐量、时延等重要指标。文章提出一种SWC-MSD(基于波长变换器的多播空分交换)模块的严格无阻塞光交换核心节点,在此基础上提出了三种调度算法,通过数学分析和实验仿真验证了算法的正确性。考察了这种核心节点在有无波长变换以及业务优先级不同的场景下阻塞率的变化情况,结果表明所提出的严格无阻塞光交换核心节点具有较低的阻塞率。     

优先级调度在交换式工业以太网中的应用研究

针对交换式以太网用于工业实时通信时不能确保数据按时送达问题,在通信站点和交换机端引入IEEE802.1p优先级服务机制,通过设置实时优先级字段来区分其不同的紧急程度的实时数据帧,并采用非抢占式固定优先级调度算法改善实时数据帧的传输时延.通过将调度分析法和网络演算法相结合,提出了一种混合的实时数据帧传输时延上界计算方法.比较研究表明该方法得到的结果比网络演算法更准确.     

基于REDP算法的动态QoS时延保障

针对无线多跳自组织网络中随机网络编码,之前提出了一种网络编码随机优先级检测调度算法(Random early detection with priority,REDP),对两条不同优先级的数据流建立Markov数学模型,推导出了引入REDP算法下数据流的单节点的时延数学表达式,该算法使得数据流能够根据自身优先级和拥塞程度调整丢包概率,从而主动丢弃数据包提前避免拥塞。文中将单节点时延问题拓展到多节点的网络拓扑结构中,提出了动态时延分配算法,该算法能够根据各个节点队列的缓存情况,动态调整各个节点的时延分配,仿真结果表明,动态时延分配算法能够实现实时数据流严格的Qo S时延保障,更利于视频、语音等实时业务流的传输。     

QoS-aware energy-saving mechanism for hybrid optical-wireless broadband access networks

Hybrid optical-wireless broadband access network (HOWBAN) takes full advantage of the high capacity and reliability of the passive optical network and the flexibility, ubiquity of the wireless network. Similar to other access networks, the issue of high energy consumption is a great challenge for HOWBAN. In HOWBAN, optical network units (ONUs) consume a great amount of energy. The sleep of ONUs can greatly improve the energy efficiency of HOWBAN. However, the quality of service (QoS) will be decreased while the packets are waiting in ONUs and optical line terminal. In this paper, we propose a QoS-aware energy-saving mechanism. A dynamic bandwidth allocation mechanism is designed to guarantee the QoS, where different priorities are considered. Meanwhile, we employ different sleep strategies by taking different priorities’ tolerant delays into account to prolong the sleep time of ONUs. Then, based on the evaluation of packet delay, the optimal sleep parameter is derived to maximum the energy efficiency. In addition, a load balancing and resource allocation mechanism is adopted in the wireless domain to reduce the delay and congestion caused by ONUs’ sleep. Results show that the proposed mechanism can effectively improve the energy efficiency and meet the QoS requirements of packets.     

Power saving with p-persistent sleep decision for wireless communications

In wireless and mobile communications systems, battery power is an essential and limited resource of portable devices. Sleep mode operation is widely used to save battery power. However, by using the sleep mode, the delay in packet transmission increases. In this paper, we propose an adaptive scheme, called the p-persistent sleep decision (SD), which controls the tradeoff between the power saving and the delay performance. The proposed p-persistent SD scheme can be used for the systems adopting frame structure with fixed length. At each beginning of frame, a node decides its state (i.e., sleep or active) for the frame, according to the result of p-persistent test, considering a variety of sleep-decision parameters, for examples, the number of queued packets and the channel condition. The performance of the p-persistent SD is evaluated by using Markov analysis. Numerical results show that we can easily control the tradeoff between the power saving and the delay performance by assigning different weights to the sleep-decision parameters. As an application example, we suggest the p-persistent SD applied to IEEE 802.11 MAC and compare its performance with that of the conventional IEEE 802.11 power save mode by using simulation. The simulation results show that the proposed scheme saves more energy under the given delay constraint. Since the proposed scheme is simple and practical, it can be applied to any star- and mesh-topology wireless networks with fixed frame length.     

Effective Energy Adaptive and Consumption in Wireless Sensor Network Using Distributed Source Coding and Sampling Techniques

Multimedia is the process of handling multiple medium of messages over network with high rate data services in wireless cellular area networks. Communication is the process of exchanging information form one service to another. In wireless networks are significantly growth of affecting network performance and energy consumption. The major problem is end to end delay in each node and meets the quality of services. The followings are considered for implementing wireless sensor network such as reduces the network delay, propagation delay and energy consumption. The senor node can sense the encoding value and reduce the network traffic delay using mitigation method. This paper propose a unique approach to provide simple routing services with reduced traffic delay, end to end delay network performance and to achieve better performance using Distributed Source Coding and Effective Energy Consumption methods. In this paper we use optimal early detection algorithm for improving network performance and energy consumption problem. An iterative Shannon fano and Tuker method is used for finding optimal solution of each node values. Network Simulator-3 is used for simulating network environments and setup the experiments. Our proposed method shows high data rate, good performance and low energy consumptions. The results compare with existing methodologies and performance is good.

     

Optimal energy efficiency routing strategy based on community in mobile social network

An optimal energy efficiency routing strategy based on community was proposed,which minimized the network energy consumption under the given delay constraint.Firstly the expected energy consumption and delay of message delivery in the connected network were obtained through Markov chain.Then the comprehensive cost function for delivering message from source node to destination node was designed,which was combined with energy consumption and delay.Thus,the optimization function to comprehensive cost of relay node delivering message was obtained,and further the reward function of relay node was gotten.Finally the optimal expected reward of optimal relay node was achieved using the optimal stopping theory,so as to realize the optimal energy efficiency routing strategy.In simulations,the average energy consumption,the average delay and the average delivery ratio of routing optimization strategy were compared with those of other routing strategies in related literatures.The results show that the strategy proposed has smaller average energy consumption,shorter average delay and higher average delivery ratio,gaining better energy consumption optimization effect.     

分簇无线传感器网络动态时隙分配MAC协议

为降低大规模无线传感器网络的平均能耗,提出了一种基于动态分配的调度型无线传感器网络MAC协议（SDC-MAC）。该协议簇间使用FDMA方式分配无线信道,簇内通过TDMA方式给各个节点分配可变长的时隙。随着簇结构的变化,簇头通过时隙分配通知,对簇内节点的时隙分配进行动态调整,簇成员节点则根据控制信息进行休眠和唤醒。仿真结果显示,该算法有效地降低了网络的平均能耗,当网络流量高时还可降低平均数据包时延。     

一种基于突发长度预测的光突发汇聚机制

提出了一种基于突发长度预测的固定时间汇聚方法.边缘节点在监测时间段内对到达的数据流进行监测,并且根据监测的结果预测在固定的汇聚时间内完成汇聚的突发包长度,提前将控制分组转发到核心网络中进行资源预留.通过理论分析及计算机仿真表明,这种汇聚方法能够有效地降低光突发交换网络中的端到端延迟.     

Data Association Coverage Algorithm Based on Energy Balance and Controlled Parameters in Wireless Sensor Networks

Based on a position-independent and computationally simple node scheduling algorithm, a scheduling algorithm based on energy balance is proposed. The analysis and simulation results showed that the algorithm can extend the lifespan of the entire network whereas ensuring energy balance. Data aggregation was a relatively time-consuming operation in sensor networks, especially in high-density networks. Therefore, minimizing the problem of data aggregation delay had become a hot topic of research. The algorithm adopted a clustering idea of low power in the cluster and high power between clusters, combined with channel allocation to reduce data aggregation delay, and data aggregation between clusters can be performed without collisions. The number of channels used in different network topologies tends to be constant.

     

A novel IP with MPLS over WDM-based broad-band wavelength switchedIP network

This paper presents a new technology for constructing IP over photonic systems. An IP with multiprotocol label switching (MPLS) over wavelength division multiplexing (WDM)-based broad-band IP network architecture and protocol is proposed and analyzed in this paper, which supports variable-length IP-like optical packet label switching and optical virtual path routing. This system tries to merge into one layer the functionalities of the wavelength switching, SONET mux/demux, and IP routing, and is sometimes known as the concept of optical MPLS. The label banding, forwarding/switching process, and node architecture of the proposed network are discussed and studied. A unique as well as important function of a lambda/label edge router (LER) is a flow assembly device that can encompass MPLS' forward equivalence classes, label stacking, and label switching path aggregation function. At the same time, a particular function of the core label switching router is wavelength merging. A fiber delay line is used to delay the data stream in order to process the label information and resolve contention. Transmission bit error rate measurements of the baseband data stream and back-to-back is also demonstrated to show its feasibility     

一种新型的光分组交换环网体系结构

提出了一种以波长为标签的新型全光变长分组交换环网的体系结构、网络节点的光分组数据包收发模型,以及防止光分组冲突的多令牌协议。使用多令牌协议的环网在进行光分组交换时,不需要高速的光子器件,无需使用延迟线、电中继以及解决光分组的冲突问题。通过数值仿真,分析了4节点、8节点和16节点环网巾光分组各种的时延特性以及网络的吞吐量特性。结果表明,当网络负载增大时,数据包的平均时延增大,同时网络节点的吞吐量和资源利用率也随之增大;网络节点数目越多,网络的吞吐率也越大。