LTE精准覆盖方法研究

本文主要是对LTE深度优化精准覆盖方法进行了研究,并开发了图形化工具,进行了现场验证。该精准覆盖工具准确率高,可操作性强,在优化规划实际工作中的指导性意义逐步显现,覆盖效果一目了然,可以指导天馈改造、居民区规划、天线选型等实际工作。     

WCDMA网络覆盖性能评估方案探析

在基于传统评估WCDMA／HSPA网络覆盖性能方案的基础上提出了新的评估方案,采用数学统计方法来评估网络质量,统计粒度小,能够客观真实反映网络覆盖问题,非常适用于网络评估及网络优化工作。     

新型LTE室内覆盖系统对比研究

本文梳理了传统室内覆盖系统应用于LTE的局限性,对三种新型LTE室内覆盖系统的结构、特性进行了分析和比较,对它们的不用应用场景进行了推荐,并给出了典型案例。     

长沙地铁电视覆盖系统建设方案设计

本文主要介绍长沙地铁2号线地铁电视所采用的基于国标(DTMB)地面数字电视技术共缆传输覆盖系统的建设方案,实现在地铁车厢内移动接受地面数字电视信号,并通过长沙地铁2号线隧道内的覆盖实例,提出与商用通讯信号共缆传输系统的设计方案与参数选择。     

多数据源关联分析评估天馈合理性的探讨

通常,对于天馈的优化往往是基于DT发现的异常事件,或者是针对用户投诉率较高的地区进行基站查勘,排查出天馈的故障以及合理性问题。文中列举了通过网管数据排查天馈故障以及通过多数据源的关联分析排查天馈合理性的新方法和新思路。     

密集市区深度覆盖研究及微基站的应用

通过对密集市区覆盖场景的细化和划分,并根据覆盖场景的特点分析微基站的适用性,提出了针对密集市区深度覆盖的思路和解决方案,最后,进一步探讨和验证了微基站工程应用的可行性及其覆盖效果,为密集市区深度覆盖提供一种有效的解决方案。     

A PSO based Energy Efficient Coverage Control Algorithm for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are large-scale and high-density networks that typically have coverage area overlap. In addition, a random deployment of sensor nodes cannot fully guarantee coverage of the sensing area, which leads to coverage holes in WSNs. Thus, coverage control plays an important role in WSNs. To alleviate unnecessary energy wastage and improve network performance, we consider both energy efficiency and coverage rate for WSNs. In this paper, we present a novel coverage control algorithm based on Particle Swarm Optimization (PSO). Firstly, the sensor nodes are randomly deployed in a target area and remain static after deployment. Then, the whole network is partitioned into grids, and we calculate each grid’s coverage rate and energy consumption. Finally, each sensor nodes’ sensing radius is adjusted according to the coverage rate and energy consumption of each grid. Simulation results show that our algorithm can effectively improve coverage rate and reduce energy consumption     

A Multi-Objective Metaheuristics Study on Solving Constrained Relay Node Deployment Problem in WSNS

This paper studies how to deploy relay nodes into traditional wireless sensor networks with constraint aiming to simultaneously optimize two important factors; average energy consumption and average network reliability. We consider tackling this multi-objective (MO) optimization problem with three metaheuristics, which employ greatly different evolutional strategies, and aim at an in-depth analysis of different performances of these metaheuristics to our problem. For this purpose, a statistical procedure is employed to analyse the results for confidence, in consideration of two MO quality metrics; hypervolume and coverage of two sets. After comprehensive analysis of the results, it is concluded that NSGA-II provides the best performance.     

The revealing power of a test case

‘Propagation, infection, and execution analysis’ (termed PIE) is used for predicting where faults can more easily hide in software. To make such predictions, programs are dynamically executed with test cases, and information concerning the test cases is collected into a histogram, each bin of which represents a single test case. The score in a bin predicts the likelihood that the test case will reveal a fault through the production of a failure (if a fault exists in the set of program locations that the test case executes). Preliminary experiments using program mutations suggest that the histogram technique presented in this paper can rank test cases according to their fault revealing ability.     

Hydration mechanisms of smithsonite from DFT-D calculations and MD simulations

Investigation on the mineral?water interactions is crucial for understanding the subsequent interfacial reactions. Currently, the hydration mechanisms of smithsonite are still obscure. In this paper, the adsorption of H₂O at different coverage rates on smithsonite (1 0 1) surface was innovatively investigated using density-functional theory (DFT) calculations and molecular dynamics (MD) simulations by analyzing adsorption model, interaction energy, atomic distance, density of state, electron density difference, concentration profile, radial distribution function and self-diffusion coefficient. We found that single H₂O preferred to be dissociated on smithsonite (1 0 1) surface via the interaction of surface Zn with the Ow of H₂O and H-bond between Hw of H₂O and surface Os. However, dissociation adsorption and molecular adsorption coexisted on the smithsonite surface at a high coverage rate of H₂O, and dissociation adsorption remained the main adsorption mechanism. Moreover, we found the interaction between smithsonite surface and H₂O was weakened as a function of H₂O coverage, which was because the presence of interlayer H₂O and different layers of H₂O decreased the reactivity of the smithsonite surface. The H₂O is mainly adsorbed on the smithsonite surface by forming three layers of H₂O (about 10–15 Å), with the ordering degree gradually decreasing.