Load Distribution of Base Stations in User-Centric Heterogeneous UDN

In ultra-dense networks(UDN),multiple association can be regarded as a user-centric pattern in which a user can be served by multiple base stations(BSs).The data rate and quality of service can be improved.However,BSs in user-centric paradigm are required to serve more users due to this multiple association scheme.The improvement of system performance may be limited by the improving load of BSs.In this letter,we develope an analytical framework for the load distribution of BSs in heterogeneous user-centric UDN.Based on open loop power control(OLPC),a user-centric scheme is considered in which the clustered serving BSs can provide given signal to interference plus noise ratio(SINR)for any typical user.As for any BS in different tiers,by leveraging stochastic geometry,we derive the Probability Mass Function(PMF)of the number of the served users,the Cumulative Distribution Function(CDF)of total power consumption,and the CDF bounds of downlink sum data rate.The accuracy of the theoretical analysis is validated by numerical simulations,and the effect the system parameters on the load of BSs is also presented.

A Successful Transmission Probability Based AP Clustering Scheme in User-Centric Cell-Free Networks

Cell-free network is a promising architecture with numerous merits in energy efficiency and macro diversity,which is easy and flexible to integrate with other communication technologies.However,its current network topology where access points(APs)are connected to a central processing unit(CPU)to jointly serve the users,causes huge burden to the fronthaul network.To deal with this problem,in this paper,we first combine thoughts in user-centric(UC)network where users are served by selected subset of APs.Then,we propose a successful transmission probability(STP)based AP clustering scheme to reduce the fronthaul capacity requirement(FCR).By using stochastic geometry and proper approximation methods,the approximated STP calculation expression is derived.Numerical simulations demonstrate that the obtained STP expression can provide a tight approximation compared to Monte Carlo simulation results under different system parameters while keeping the computation tractable.Furthermore,the relationship between the FCR and the STP threshold is formulated as a clustering optimization problem,which gives insights on clustering design in UC-CF network systems.We show by simulation results that the proposed scheme requires less fronthaul capacity than the original CF approach while ensuring the STP performance.

A Proactive Selection Method for Dynamic Access Points Grouping in User-centric UDN

Network densification is a promising solution to fulfill network capacity requirement and transmission rate for beyond 5G and 6G wireless communications.Ultra-dense network(UDN)integrates heterogeneous network resources and coordinates technologies on quality of service controlling,to provide users with flexible service.However,dense deployment reduces coverage radius of the cell,resulting in an increase on handover frequency,which makes a serious impact on service continuity.In this paper,we propose a proactive selection method for dynamic access points grouping(DAPGing)in accordance with“user-centric”philosophy,which selects target Access Points(AP)and reduces handover times to ensure communication continuity.This method includes two criteria:1)the user’s sojourn time,which is determined by analyzing the AP coverage area;2)neighbor relationship between APs,which is determined by coverage area and signal strength characteristics between neighboring APs.Therefore,candidate APs become the proactive selected ones to update the AP group.Stochastic geometry is used to build system model and performance metrics are analyzed,including AP group coverage probability and average update frequency.Experimental analysis shows that the proposed proactive selection method brings similar coverage probability to traditional handover method,while average update frequency is reduced more than 20%selection criteria.

A survey on user-centric cell-free massive MIMO systems

The mobile data traffic has been exponentially growing during the last several decades.This was enabled by the densification of the network infrastructure in terms of increased cell density(i.e.,Ultra-Dense Network(UDN))and/or the increased number of active antennas per Access Point(AP)(i.e.,massive Multiple-Input Multiple-Output(mMIMO)).However,neither UDN nor mMIMO will meet the increasing demand for the data rate of the Sixth Generation(6G)wireless communications due to the inter-cell interference and large quality-of-service variations.Cell-Free(CF)mMIMO,which combines the best aspects of UDN and mMIMO,is viewed as a key solution to this issue.In such systems,each User Equipment(UE)is served by a preferred set of surrounding APs cooperatively.In this paper,we provide a survey of the state-of-the-art literature on CF mMIMO.As a starting point,the significance and the basic properties of CF mMIMO are highlighted.We then present the canonical framework to discuss the essential details(i.e.,transmission procedure and mathematical system model).Next,we provide a deep look at the resource allocation and signal processing problems related to CF mMIMO and survey the up-to-date schemes and algorithms.After that,we discuss the practical issues in implementing CF mMIMO and point out the potential future directions.Finally,we conclude this paper with a summary of the key lessons learned in this field.

Semantics-oriented approach for information interoperability and governance:towards user-centric enterprise architecture management

Enterprise architecture (EA) efforts focus on business, technology, data, and application architecture, and their integration. However, less attention has been given to one of the most critical EA elements, i.e., users (EA audiences). As a result, existing EA management systems (EAMS) have become old, large, content-centric document-repositories that are unable to provide meaningful information of use to the enterprise users and aligned with their needs and functional scope. We argue that a semantic technology based mechanism focusing on enterprise information and user-centricity has the potential to solve this problem. In this context, we present a novel ontology-based strategy named the user-centric semantics-oriented EA (U-SEA) model. Based on this model, we have developed a user-centric semantics-oriented enterprise architecture management (U-SEAM) system. Our approach is generic enough to be used in a wide variety of user-centric EAM applications. The results obtained show computational feasibility to integrate and govern enterprise information and to reduce complexity with respect to interoperability between enterprise information and users.

Joint association and beamforming optimization in reconfigurable intelligent surface-enhanced user-centric networks

Fully coordinated Cell-Free(CF)networks can alleviate the Inter-Cell Interference(ICI)for the cell-edge users in cellular networks.Due to the complex topology of the association between the Access Points(APs)and the users in CF networks,it is challenging to deploy CF networks in practical scenarios.In order to make CF networks feasible,we introduce User-Centric(UC)networks enabling each user served by a limited number of APs.As a low-cost and energy-efficient technology,Reconfigurable Intelligent Surface(RIS)can be embedded in UC networks to further improve the system performance.First,we provide a brief survey on the prior works in UC networks for clear comprehension.Then,we formulate a Spectral Efficiency(SE)maximization problem for RIS-enhanced UC networks.For solving the non-convex problem,we divide it into three subproblems and propose a joint optimization framework for optimizing AP-user association,active beamforming of multiple antennas at the APs,and the passive beamforming of the RIS.Besides,a channel gain based association method coupled with the design of RIS is proposed to construct a dynamic and efficient association.The subproblems about optimizing active and passive beamforming are solved with the fractional programming.Simulation results show that the proposed joint optimization framework for RIS-enhanced UC networks can obtain good SE compared with other benchmark schemes.

The Intersection of Privacy by Design and Behavioral Economics: Nudging Users towards Privacy-Friendly Choices

This paper conducts a comprehensive review of existing research on Privacy by Design (PbD) and behavioral economics, explores the intersection of Privacy by Design (PbD) and behavioral economics, and how designers can leverage “nudges” to encourage users towards privacy-friendly choices. We analyze the limitations of rational choice in the context of privacy decision-making and identify key opportunities for integrating behavioral economics into PbD. We propose a user-centered design framework for integrating behavioral economics into PbD, which includes strategies for simplifying complex choices, making privacy visible, providing feedback and control, and testing and iterating. Our analysis highlights the need for a more nuanced understanding of user behavior and decision-making in the context of privacy, and demonstrates the potential of behavioral economics to inform the design of more effective PbD solutions.

基于深度强化学习的无蜂窝系统无线接入点选择算法

面向以用户为中心的无蜂窝分布式多输入多输出(Multiple-Input Multiple-Output, MIMO)架构,研究利用不完备信道状态信息(Channel State Information, CSI)下实现无线接入点(Access Point, AP)与用户(User Equipment, UE)之间的选择,提出基于深度强化学习(Deep Reinforcement Learning, DRL)的高效分配算法,通过使用不完备CSI快速生成以用户为中心的AP集合,减少了对前馈链路容量的占用。仿真结果表明,与其他传统选择算法相比,所提出的DRL接入点选择算法可以获得至少22.48%的总遍历频谱效率增益;与深度Q网络(Deep-Q-Network, DQN)算法相比,可以获得约14.17%的总频谱效率增益。

有机秩序视阈下的城市公园公共设施设计方法

目的城市公园作为典型室外公共空间之一,其使用者的多样性、空间环境的复杂性、时间变化的异质性等不确定因素,往往给设计师们带来巨大的挑战。在连续不断的时间中,探究使用者的空间行为规律,并根据其行为特征提出可供设计师参考的,具有实践价值的理论依据。方法从城市公园有机秩序出发,应用分时行为地图注记法,按不同时间层段研究城市公园空间中的用户行为。结果通过对上海市内不同行政区划的14个公园展开为期半年(共计2538人次)的田野调查,发现了各类用户行为与设施设计间的“错位”问题,提出公园公共设施设计应在原有追求局部设计人性化的基础上,对于跨时间段的空间及其公共设施设计进行优化,尊重空间使用者的使用逻辑及其活动时间秩序规律的有机秩序化设计方法。同时,通过归纳分析构建了城市公园宏、中、微观有机秩序模式,解析有机秩序时间分层段结构的空间行为。结论公园中公共设施的有机秩序化设计能长期有效地满足不同时段不同用户的需求,并通过设计鼓励促进空间中小群活动的产生,同时带动空间活动达到理想的有机秩序的状态。有机秩序化设计关注的是随着时间变化而持续产生的“人性化”设计体验,是对于原本“人性化”设计理念的提升。

面向Sub-7 GHz频段分布式超大规模MIMO技术

下一代移动通信系统将在新的频段进一步提升整体性能。面向未来6G系统在Sub-7 GHz频段部署所面临的连续覆盖、容量提升以及部署困难等潜在难题,提出了一种创新的总体方案。这一方案结合了以用户为中心的接入网架构与分布式超大规模MIMO技术,旨在实现更高效的通信性能和用户体验。在所提出的以用户为中心的网络构架中,系统能够突破中心化限制,构建出中心网络与边缘分布式网络结合的以用户为中心的端到端分布式自治网络,智能自适应端到端用户需求。基于该构架可通过动态调整小区的覆盖范围和容量,更好地应对不同场景下的用户需求。通过优化连接管理策略,可以有效减少连接中断和延迟,提升系统的稳定性和用户的满意度。针对上述接入网络构架,给出了分布式超大规模系统中的灵活小区构建、链接管理及接入过程方案,并对CSI测量上报、分布式天线校准等底层核心问题进行了分析。

The Influence of a User-Centred Design Focus on the Effectiveness of a User Interface for an Agricultural Machine

As agricultural machines become more complex, it is increasingly critical that special attention be directed to the design of the user interface to ensure that the operator will have an adequate understanding of the status of the machine at all times. A user-centred design focus was employed to develop two conceptual designs (UCD1 & UCD2) for a user interface for an agricultural air seeder. The two concepts were compared against an existing user interface (baseline condition) using the metrics of situation awareness (Situation Awareness Global Assessment Technique), mental workload (Integrated Workload Scale), reaction time, and subjective feedback. There were no statistically significant differences among the three user interfaces based on the metric of situation awareness;however, UCD2 was deemed to be significantly better than either UCD1 or the baseline interface on the basis of mental workload, reaction time and subjective feedback. The research has demonstrated that a user-centred design focus will generate a better user interface for an agricultural machine.

Towards Specifications for Automatic Recognition Software:An Example of a User-Centred Design

This article describes a user-centred method used to design innovative pattern recognition software for technical paper documents. This kind of software can make some errors of interpretation. It will therefore be important that human operators are able to identify and correct these mistakes. The identification of errors is a difficult task because operators need to establish co-reference between the initial document and it interpretation. Moreover, users must be able to checks the interpretation without forgetting any area. This task requires the interface is easy to use. The experiments showed that the sequential display of interpretation is the most effective and that the interruptions by user reduce task duration. Moreover, queries by the system may improve error detection. This paper summarizes the main results of the research conducted in the context of this design for enhance the interface, and describes the specifications to which it gave rise.

面向6G的用户为中心网络研究综述

与第5代移动通信网络(5G)相比,第6代移动通信网络(6G)有望引入新的性能指标和应用方案,如全球覆盖、更高的频谱/能源/成本效率、更高的智能和安全水平。用户为中心网络(UCN)将成为实现6G的关键推动者,因为其突破了传统基站为中心网络并与信息产业的新兴技术形成了有效融合。该文将从物理层的信道估计和预测、网络上层的性能分析以及链路层的无线资源管理等方面综述这一新型网络的研究现状。首先,讨论和分析UCN的概念和总体网络架构;其次,总结UCN网络中信道估计预测方法、性能分析策略和无线资源管理(RRM)方案;最后,在广泛的调研基础上,探讨UCN网络中的开放性问题,为今后的研究方向提供思路。此综述旨在使读者快速而全面地了解UCN的当前技术状况,从而吸引更多的研究人员进入这一领域。

外向型汉语学习词典的供需错位和出路

外向型汉语学习词典存在“需求大出版多而用户少”的供需错位,其主要原因是缺乏用户意识,更谈不上用户中心,以检索查检方式、收词规模、可理解性和词典介质四个维度为例分析用户需求和已有词典的错位,可以得出汉语学习词典欲走出困境,须做到:(1)在理念上从“编者中心”切实转向“用户中心”;(2)词典生产手段要实现电子化、数据化、融媒化、平台化,充分利用融媒词典编纂和使用平台创造机会使用户全程“参与”词典的编纂和完善,实现编者和用户的角色融合;(3)词典研究方法上应加强定量研究和实证研究,充分利用用户查询数据为词典优化提供支撑;(4)词典评价环节也应站在用户的角度为“用户中心”保驾护航。

6G以用户为中心接入网的下行功率分配研究

为满足6G对大数据量、用户一致性服务等需求,业界提出以用户为中心的6G网络架构,并探讨资源管理、移动性管理等关键问题。文章针对6G以用户为中心的接入网,研究资源管理问题中的下行功率分配,提出基于用户接收功率的比例功率分配算法。具体包括建立基于下行联合传输的UCAN系统模型,推导用户信噪比、传输速率和频谱效率表达式,基于针对每个用户的传输质量个性化满足原则,提出基于用户接收功率的比例功率分配算法,同时针对该算法设计了易于工程实现的方案。仿真结果显示,文章提出的比例功率分配算法相较以网络为中心的功率分配算法能够提升单个用户下行信噪比,从而提升网络下行平均吞吐量,并使网络中用户获得一致性体验。

面向XR业务的以用户为中心的接入网

扩展现实(eXtened Reality,XR)业务作为6G沉浸式通信场景的代表性业务,具有高吞吐量、低时延和高可靠性等要求。传统蜂窝网架构具有小区边缘性能差、小区间切换带来服务中断时延等问题。一些已有的优化方案如条件切换、双激活协议栈等可以保证业务连续,但无法提供稳定的高速率服务。因此需要以用户为中心的接入网架构为用户提供一致性的高质量服务。文章首先分析XR业务的需求和挑战,然后提出满足XR业务的以用户为中心的接入网解决方案,并研究其关键技术,包括灵活小区管理、网络功能和资源管理、高效协作调度、业务下沉及以用户为中心架构下的内生AI。最后进行系统级仿真,结果表明以用户为中心的接入网对XR业务系统容量的增益在30%以上。

5G网络技术研究现状和发展趋势

首先分析了5G网络中的新需求对移动通信网络的挑战,从而说明进行5G网络技术研究的必要性。随后,介绍了目前国内外研究组织在5G网络相关技术的研究进展,包括NGMN、5GPPP、IMT-2020等,同时也介绍了国内外标准化组织对5G网络技术的标准化研究进展。基于对5G网络中的新需求、新挑战的分析,结合国内外关于5G网络技术研究现状的总结,预测了未来5G网络技术的发展趋势并给出了相关的技术发展方向。最后对5G网络的发展进行了总结和展望。

参与式感知:以人为中心的智能感知与计算

越来越多的无线智能移动设备集成了大量不同种类的传感器模块,与此同时无线移动网络也迅速普及.这些因素推动了参与式感知概念的提出与发展.参与式感知又被称为城市感知、以用户为中心的感知、群智感知.参与式感知可以解决传统无线传感网络难以大规模部署以及部署成本高昂的问题.参与式感知系统通过利用移动智能设备中的传感器、社交网络以及个人设备使用行为对参与者周围的物理环境、社会环境或者个人状态进行自主式采集、传输和分析,并做出智能化决策.这对未来实现智慧城市、普适计算以及物联网等重大概念具有重要的意义.首先介绍了参与式感知相关概念、理论以及相应的应用原型系统;然后介绍了参与式感知相关研究前沿热点,包括参与式感知的原型设计、感知数据处理、激励机制、隐私保护、恶意攻击以及不同移动网络的问题等;最后给出研究参与式感知的一般方法.

基于软件定义的以用户为中心的5G无线网络架构

5G无线接入网络是一种复杂的异构网络,各个协议之间的封闭性限制了网络性能。为了统一管理异构网络,向用户提供个性化的服务,提出了一种基于软件定义的以用户为中心的新型网络架构。该架构通过软件定义的形式统一管理所有无线网络,打破了传统蜂窝小区的概念,针对每个用户生成以用户为中心的小区,小区内的所有基站都能为该用户提供服务。这种新的网络架构能够为用户提供个性化的网络服务,提升用户的峰值速率和边缘用户性能。

基于数字预案的应急处置流程构造方法

为了能够在应急处置中有效利用应急预案,并解决应急处置流程构造中的不确定性,提出一种基于数字预案的应急处置流程构造方法。根据应急预案中包含的应急事件以及与处置相关的组织、规则和预定义的流程,给出了数字预案的定义。基于数字预案,在应急处置流程构造过程中为用户推荐应急响应级别和应急活动,形成一种以用户为中心、预案辅助决策的应急处置流程构造方法。结合应急处置的实例和相关工作,对方法进行了分析和评价。