高海拔寒冷地区LTE接入网能效评估与节能研究

流量爆炸式增长导致空口带宽和LTE基站数量激增,网络规模扩大导致能耗逐年上升.对无线网络能效进行测算与评估,提高网络能源使用效率,显著降低网络能耗,成为业界的研究重点.针对现有能效测算方法的不足,提出基于绿色无线通信技术的网络能效评估与测算体系和能耗结构模型,并就四川高海拔寒冷地区LTE接入网络的特征、主要节能技术应用进行探讨.     

基于能效和异构服务的密集家庭小区资源分配

密集家庭小区网络提高了网络容量,同时也严重增大了网络的能耗。为了提高家庭基站网络的能效,针对密集家庭小区场景,联合考虑家庭用户的异构服务、电路功率、网络的跨层干扰,提出了最大化家庭用户总能效的资源分配算法,利用Dinkelbach理论和拉格朗日对偶分解理论,求解了该优化问题的闭式解,并分析了算法复杂度。仿真结果表明,所提的资源分配算法具有更高的网络能效,比已有资源分配算法的能效提高了约20%。     

基于多小区通信系统能效优化研究

随着移动信息产业的发展,无线通信设备剧增,通信系统能耗也随之增加。不断攀升的系统能耗问题制约了移动通信的发展,以基站资源块和发射功率的最优分配方案来提高无线通信系统能效(EE,Energy Efficiency,能量效率)已经成为当下研究的热点。文章首先构造了系统能效优化的函数,采用KKT、凸优化的算法,获得最大的系统能效。然后针对系统能效优化的系统模型进行分析,对不同网络场景下的能效优化研究现状进行综述。最后,对多小区通信系统能效优化的研究进行了总结与分析。     

热点区域内能效最优的单中继部署策略

通信过程产生的能耗问题日益严峻。绿色通信作为一个全新的理念,旨在确保网络性能(如容量等)的同时尽可能降低能耗。在新一代的无线通信网络中,协作中继作为一项候选技术,能够有效提升网络容量和能效。文章在热点区域内研究以能效最大化为目标的最优中继位置问题。仿真结果表明,能够通过优化中继位置获得最大能效,并通过与无中继网络进行性能对比,表明文章提出的策略能够有效提高上行传输能效。     

内容中心网络中能效感知的概率性缓存机制

内置缓存技术是内容中心网络(Content Centric Networking, CCN)的核心技术之一。现有的研究大多主要针对网络资源利用率的优化,而忽略了网络能耗的问题。该文首先建立了一个能耗模型对CCN的网络能耗进行分析,并设计了一个能效判决条件来优化缓存过程的能效性。进而,在此基础上综合考虑内容流行度和节点中心性等因素提出一种能效感知的概率性缓存机制(E2APC)。仿真结果表明,该机制能在保证较高的缓存命中率和较小的平均响应跳数的同时有效地降低网络的整体能耗。     

一种基于C-RAN架构的LTE网络能效获取方法

提供了一种从单位流量能耗视角的LTE网络能效获取方法,弥补了现有技术不能对C-RAN架构下各网络子单元分别测算能效的不足。该方法包括收集流量清单和能耗清单,根据预设标记与过滤规则分别采集并上报无线网络中各网络子单元的实时流量和实时能耗。最后,根据流量清单、能耗清单以及预设时隙,获取各网络子单元和/或无线网络的能效。     

数据中心能效优化策略研究

数据中心数量及规模的增长使得数据中心能耗问题愈发凸显,多国政府针对数据中心能耗问题制定了相应的政策、法规,以促进数据中心节能。对数据中心能耗构成及能效指标进行了研究,从供配电系统、制冷系统及IT设备3个方面对数据中心能效影响因素进行了分析,然后对当前主流的数据中心能效优化策略进行了总结;在此基础上,提出了数据中心即服务的能效优化策略,该能效优化策略充分考察了数据中心服务性能和能耗的匹配性,能够有效实现数据中心全局能效优化。     

绿色基站能效评估技术及发展趋势

近十年来移动通信行业高速发展,网络规模急剧扩大,能耗呈指数增长趋势.基站能效评估已成为当前推动移动通信网络节能减排的重要手段,并发挥了重要作用.国内外标准化组织相继开展通信产品能效评估方法的研究工作,有计划、有步骤地推动能效评估方法的标准化.     

LTE基站能效测试与分析

随着LTE网络建设的深入,LTE基站数量不断增加,用户数与网络流量快速增长,网络能耗问题越发突出,由于无线接入网能耗占移动通信系统能耗的80%以上,其中基站能耗占比最大,基站的功耗成本成为运营商最主要的运营支出费用之一。然而目前缺乏有效的LTE设备能耗测试方法与测试数据,无法为运营商的节能减排工作提供指导,降低运营成本。针对该问题,建立了基站动态负荷能效模型,通过对LTE基站设备进行能耗测试与分析,掌握影响LTE基站主设备能效的因素,比较了不同网络、不同制式基站设备的能效,从节能的角度为LTE规划、采购、建设、优化提供建议。     

射频供能无线传感器网络高能效数据收集方案

在射频供能无线传感器网络中,提高网络能效和吞吐率是一个重要的研究问题.该文统筹考虑信道分配、节点的能量阈值以及MAC（Medium Access Control）帧分块重传机制,提出高能效和高吞吐率的数据收集方案;推导了节点的充电时间、节点传输一个MAC帧的平均能耗和平均时延、网络能效和吞吐率,定义了网络效用函数,形成了最大化网络效用的优化问题.通过调整效用系数并求解优化问题,可以获得使网络能效和吞吐率最大化的最优能量阈值和MAC帧最优分块个数.仿真结果表明,所提方案的能效和吞吐率高于已有方案.     

移动互联网业务对基站能耗的影响

快速发展的移动互联网业务,为运营商带来了诸多挑战,业务特性与网络能耗之间的映射关系尚属空白。为了准确评估业务对网络资源的影响以及网络设备由此产生的能耗,深入物理层资源粒度,提出一种改进的“二次线性映射”模型及四步建模思路,同时选取了11种典型业务场景,定量评估数据、信令分别消耗的网络资源和能耗大小,便于业务能耗的精细化管理和运营管控,为降低端到端资源开销和业务能耗打下基础。     

人工智能在智慧能源管理中的应用研究

物联网和云计算等技术的发展使得数据中心呈现爆炸性的增长,数据中心能耗大、能效利用率低、能耗和能效管理信息化程度不高,造成能源的巨大浪费。本文基于人工智能算法,从能耗指标PUE智能优化和能量智能管理调度角度,提供智慧能源管理解决方案。     

Energy-efficient and QoS-supported deployment strategy of dense Macro-Femto cellular network

With the exponentially increasing of users’ demand for mobile data traffic,massive small cells have been deployed to satisfy the users’ quality of service (QoS) by operators.However,a significant energy would be consumed caused by dense deployment.To this end,a dense heterogeneous cellular network deployment strategy was proposed with QoS guarantee to decline system energy consumption.Firstly,a dense Macro-Femto biased cellular network was used to build the network model,the two QoS indicators of SINR coverage and user average rate was analyzed by stochastic geometry theory.Then,under the condition of QoS constraint,average spatial power consumption (ASPC) was taken as the optimization goal,optimal deploy density and transmission power of Femto were achieved by using optimization theory.Finally,the experimental results show that,comparing with the traditional strategy which only considering base station density,the proposed strategy has advantages in terms of energy efficiency while QoS guarantee.     

无线EH认知物联网网络资源分配研究

由于5G技术的快速发展,基于能量采集的认知物联网(Internet of things,IOT)具有很大的应用前景。针对无线物联网网络中存在的"doubly-near-far"问题,考虑在认知物联网网络中将能量采集与信息接收站分开管理,提出了一个基于能量采集的异构认知物联网网络模型,实现用户能效的最大化。此外,该模型不仅考虑能量采集,还考虑了频谱利用率低、频谱资源稀缺的问题,针对该网络优化问题,提出了一个混合整数非线性规划问题,通过信道分配、功率控制以及时间分配的联合优化的方法,考虑用户数据速率、干扰约束的同时,最大化能效。仿真实验结果证明了所提出模型以及算法的有效性。     

基于话务负荷的自适应绿色基站

构筑环境友好的生产模式,高效使用有限的能源,是运营商现阶段的研究重点。文章探讨了一种基于话务承载情况自适应调整能源消耗的模式,能在不损失业务承载能力和性能的前提下降低电力消耗,并针对现网的话务模型进行算法优化。应用结果显示该模式切实可行,利于推广,能在通信系统性能与节能目标间实现有效平衡。     

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.     

Energy efficiency of TCP: An analytical model and its application to reduce energy consumption of the most diffused transport protocol

Energy efficient communications become a challenge for both industries and researchers. Incorporating energy efficiency into the design of network protocols and architectures represents a relevant issue in networking research. Currently, very few works address energy efficiency as a fundamental feature of network protocols. This paper benchmarks energy efficiency of TCP to understand the parameters and operational mechanics that determine and contribute to energy consumption. We propose an analytical model with energy consumption to protocol operation cycles and novel optimization techniques for reducing energy consumption of TCP. The evaluation results, obtained from NS2 simulations, demonstrate that even minor modifications of the protocol behavior can bring significant savings of energy. Copyright © 2015 John Wiley & Sons, Ltd.     

Energy spectral efficiency tradeoff in downlink OFDMA network

Spectral efficiency (SE) is an important metric in traditional wireless network design. However, as the development of high‐data rate services and rapidly increase of energy consumption, energy efficiency (EE) has received more and more attention. In this paper, we investigate the EE–SE tradeoff in downlink OFDMA network. Different from previous researches, we try to optimize EE and SE simultaneously. First, the problem is formulated as a multiobjective optimization problem (MOP), and its Pareto optimal set is characterized. Then, we convert the MOP to a single‐objective optimization problem (SOP) by the weighted linear sum method and show that it is neither quasi‐convex nor quasi‐concave. After that, a novel algorithm using particle swarm optimization is proposed to solve the SOP. Simulation results validate that the proposed algorithm can efficiently reduce total transmit power and improve EE, although the cost is sacrificing some SE, which could be used to design an flexible energy efficient network in the future.Copyright © 2014 John Wiley & Sons, Ltd.     

In-network caching for energy efficiency in content-centric networking

Recently, Internet energy efficiency is paid more and more attention. New Internet architectures with more energy efficiency were proposed to promote the scalability in energy consumption. The eontent-eentrie networking （CCN） proposed a content-centric paradigm which was proven to have higher energy efficiency. Based on the energy optimization model of CCN with in-network caching, the authors derive expressions to tradeoff the caching energy and the transport energy, and then design a new energy efficiency cache scheme based on virtual round trip time （EV） in CCN. Simulation results show that the EV scheme is better than the least recently used （LRU） and popularity based cache policies on the network average energy consumption, and its average hop is also much better than LRU policy.