Joint User Association and Satellite Selection for Satellite-Terrestrial Integrated networks

In this paper, we investigate a cooperation mechanism for satellite-terrestrial integrated networks. The terrestrial relays act as the supplement of traditional small cells and cooperatively provide seamless coverage for users in the densely populated areas.To deal with the dynamic satellite backhaul links and backhaul capacity caused by the satellite mobility, severe co-channel interference in both satellite backhaul links and user links introduced by spectrum sharing,and the difference demands of users as well as heterogeneous characteristics of terrestrial backhaul and satellite backhaul, we propose a joint user association and satellite selection scheme to maximize the total sum rate. The optimization problem is formulated via jointly considering the influence of dynamic backhaul links, individual requirements and targeted interference management strategies, which is decomposed into two subproblems: user association and satellite selection. The user association is formulated as a nonconvex optimization problem, and solved through a low-complexity heuristic scheme to find the most suitable access point serving each user. Then, the satellite selection is resolved based on the cooperation among terrestrial relays to maximize the total backhaul capacity with the minimum date rate constraints. Finally,simulation results show the effectiveness of the proposed scheme in terms of total sum rate and power efficiency of TRs' backhaul.

Elevation, Slope Aspect and Integrated Nutrient Management Effects on Crop Productivity and Soil Quality in North-west Himalayas, India

On farm bio-resource recycling has been given greater emphasis with the introduction of conservation agriculture specifically withclimate change scenarios in the mid-hills of the north-west Himalaya region（NWHR）. Under this changing scenario, elevation, slope aspect and integrated nutrient management（INM） may affect significantly soil quality and crop productivity. A study was conducted during 2009-2010 to 2010-2011 at the Ashti watershed of NWHR in a rainfed condition to examine the influence of elevation, slope aspect and integrated nutrient management（INM） on soil resource and crop productivity. Two years of farm demonstration trials indicated that crop productivity and soil quality is significantly affected by elevation, slope aspect and INM. Results showed that wheat equivalent yield（WEY） of improved technology increased crop productivity by -20%-37% compared to the conventional system. Intercropping of maize with cowpea and soybean enhanced yield by another 8%-17%. North aspect and higher elevation increased crop productivity by 15%-25% compared to south aspect and low elevation（except paddy）. Intercropping of maize with cowpea and soybean enhanced yield by another 8%-15%. Irrespective of slope, elevation and cropping system, the WEY increased by -30% in this region due to INMtechnology. The influence of elevation, slope aspect and INM significantly affected soil resources（SQI） and soil carbon change（SCC）. SCC is significantly correlated with SQI for conventional（R2 = 0.65＊）, INM technology（R2 = 0.81＊） and for both technologies（R2 = 0.73＊）. It is recommended that at higher elevation.（except for paddy soils） with a north facing slope, INM is recommended for higher crop productivity; conservation of soil resources is recommended for the mid hills of NWHR; and single values of SCC are appropriate as a SQI for this region.

Integrated Nutrient Management of Safflower (<i>Carthamus tinctorius</i>L.) under Rainfed Conditions

Optimistic and sustainable supply of soil available nutrients to crop plants enhances productivity. Integrated nutrient management (INM) approach can improve soil fertility on long term basis. The present study was conducted to determine effects of INM on quantitative and qualitative characters of two Safflower (Carthamus tinctorius L.) cultivars “Thori-78 and Leed-00”. Five treatments using different composition of poultry litter, farm yard manure, nitrogen and phosphorous fertilizers with recommended dose as a control measure were replicated thrice in randomized complete design. The results of field trial depicted maximum plant height (174.6 cm), number of heads plant-1 (42.67), number of seeds head-1 (59.0), thousand seed weight (42.26 g), biological yield (3089 Kg·ha-1) and seed yield (455.2 Kg·ha-1) recorded from combined application of FYM @ 2 t·ha-1and Half (N-P) (soil application) (T5) in Genotype “Leed-00” which was statistically different from all other treatments. Thori-78 also showed increase in yield and yield components under the same treatment (T5) i.e.2 t·ha-1 FYM and Half (N-P).No effect of INM was found on fatty acid composition of safflower cultivars. The correlation coefficients illustrated positive and significant association of seed yield with plant height (0.89), number of heads pod-1 (0.86) and number of seeds head-1 (0.83) as a result of application of selected treatment. These results demonstrated the significance of INM in safflower yield improvement under rainfed conditions.

A device information-centered accelerator control network management system

Purpose The control network is a critical infrastructure that supports the stable operation of the accelerator.Each device accessing the control network has different device information,such as IP address,MAC address,connected switches and ports,device location and purpose.Accurately maintaining the mapping relationship between these device information facilitates network management.It helps inventory assets,fault location and provide visibility into dynamic changes of device on the network.However,existing tools cannot fully satisfy these demands.They only map some information and lack details important for accelerator facilities like device location and purpose.Additionally,they only reflect the current status rather than indicating dynamic changes across all devices over time.As intelligent devices proliferate,the scale of the control network is rapidly expanding,posing greater challenges in maintaining mapping relationships.Methods This paper proposes a device information-centered Accelerator Control Network Management System(ACNMS).It establishes a device information management framework and allows network administrators to perceive the dynamic changes of devices on the network.The system adopts a layered architecture.Back-end modules implement the core logic of all functions.The graphical user interface presents data and provides a management portal.Results The system test on the control network of the National Synchrotron Radiation Laboratory demonstrates that it can meet the functional design objectives.The application scenarios of the ACNMS are further expanded through system integration and combination with network automation.Conclusion The ACNMS has proven to be an efficient network management tool that significantly improves the operation and maintenance efficiency of the accelerator control network.

Realizing Intelligent Spectrum Management for Integrated Satellite and Terrestrial Networks

Nowadays both satellite and terrestrial networks are expanding rapidly to meet the ever-increasing demands for higher throughput,lower latency,and wider coverage.However,spectrum scarcity places obstacles in the sustainable development.To accommodate the expanding network within a limited spectrum,spectrum sharing is deemed as a promising candidate.Particularly,cognitive radio(CR)has been proposed in the literature to allow satellite and terrestrial networks to share their spectrum dynamically.However,the existing CR-based schemes are found to be impractical and inefficient because they neglect the difficulty in obtaining the accurate and timely environment perception in satellite communications and only focus on link-level coexistence with limited interoperability.In this paper,we propose an intelligent spectrum management framework based on software defined network(SDN)and artificial intelligence(AI).Specifically,SDN transforms the heterogenous satellite and terrestrial networks into an integrated satellite and terrestrial network(ISTN)with reconfigurability and interoperability.AI is further used to make predictive environment perception and to configure the network for optimal resource allocation.Briefly,the proposed framework provides a new paradigm to integrate and exploit the spectrum of satellite and terrestrial networks.

Interference management in 6G space and terrestrial integrated networks: Challenges and approaches

The Space-Terrestrial Integrated Network(STIN)is considered to be a promising paradigm for realizing worldwide wireless connectivity in sixth-Generation(6G)wireless communication systems.Unfortunately,excessive interference in the STIN degrades the wireless links and leads to poor performance,which is a bottleneck that prevents its commercial deployment.In this article,the crucial features and challenges of STIN-based interference are comprehensively investigated,and some candidate solutions for Interference Management(IM)are summarized.As traditional IM techniques are designed for single-application scenarios or specific types of interference,they cannot meet the requirements of the STIN architecture.To address this issue,we propose a self-adaptation IM method that reaps the potential benefits of STIN and is applicable to both rural and urban areas.A number of open issues and potential challenges for IM are discussed,which provide insights regarding future research directions related to STIN.

Space-Terrestrial Integrated Mobility Management via Named Data Networking

In Future Space-Terrestrial Integrated Networks （FSTINs）, mobility is the norm rather than the exception, the current TCP/IP architecture is not competent. As a promising future network architecture, Named Data Networking （NDN） can support content consumer mobility naturally, but the content producer mobility support remains a challenging problem. Most previous research simply considered this problem in terrestrial scenarios, which involve stable infrastructures to achieve node mobility management. In this paper, we consider the problem in an FSTIN scenario without special handover management infrastructures. Specifically, we propose a tracing-based producer mobility management scheme and an addressing-assisted forwarding method via NDN architecture. We formally describe Multi-Layered Satellite Networks via a Time Varying Graph model and define the foremost path calculating problem to calculate the route of space segment, as well as an algorithm that can function in both dense （connected） and sparse （delay/disruption tolerant） scenarios. Finally, we discuss the acceleration method that can improve the Space-Terrestrial Integrated forwarding efficiency. Performance evaluation demonstrates that the proposed scheme can support fast handover and efficient forwarding in the FSTIN scenario.

6G星地融合网络资源管理关键技术

卫星网络因具备弥补地面网络覆盖盲区的特性,成为6G网络实现泛在连接应用场景的关键技术之一。为了实现卫星网络和地面网络间高效的资源融合管理,首先简要介绍了星地融合网络的发展现状,总结了星地融合网络资源管理技术的研究现状以及面临的挑战。其次,对6G星地融合网络下的移动性管理、跨域多维资源管理和统一的空口协议设计等关键技术进行分析,并基于对现有研究的探讨给出解决方案。最后,对未来面向6G的星地融合网络资源管理的发展提出了新的展望。

星地融合网络管控架构设计

星地融合网络的运行管控需要面向巨型星座和天地大尺度网络,实现对异构基础设施、分层立体网络、跨域多维资源、定制化业务服务的综合调度管理,管控对象多样,关系错综复杂,管控的协同性和高效性直接影响网络的服务能力。针对以上问题,基于网络为本、星网协同的理念,探索星座、网络、业务的协同管控机制,提出星地融合网络运行管控的总体架构,并详细设计管控中心功能,规划典型运行管理流程,分析其在巨型星座在轨管理和大尺度跨域网络管理等方面的适用性,为星地融合网络运行管控系统建设和系统运行管理提供技术支撑。

星地融合网络中基于无监督图学习的卫星切换方法研究

随着未来6G移动通信研究的快速发展,星地融合通信将是满足全域覆盖、泛在接入的重要技术。在星地融合网络中切换决策直接影响网络性能与服务持续性,现有切换算法主要通过实时监测候选卫星状态,计算权重进行切换判决,难以适应高动态星地网络中时空周期异步的切换决策。提出一种基于无监督图学习的卫星切换方法,引入卫星覆盖时空图表征网络连接关系,设计前向蚂蚁和后向蚂蚁发现并反馈的信息素感知机制,建立图学习模型,挖掘卫星覆盖时空图中卫星节点、用户节点与连接关系之间的隐式特征信息和拓扑信息,将切换决策问题转化为求解节点和边之间的连接关系概率,同步切换决策周期。仿真结果验证了所提卫星切换方法具有较快的收敛速度,切换时延降低20%。

Joint UE Location Energy-Efficient Resource Management in Integrated Satellite and Terrestrial Networks

Integrated satellite and terrestrial networks can be used to solve communication problems in natural disasters,forestry monitoring and control,and military communication.Unlike traditional communication methods,integrated networks are effective solutions because of their advantages in communication,remote sensing,monitoring,navigation,and all-weather seamless coverage.Monitoring,urban management,and other aspects will also have a wide range of applications.This study first builds an integrated network overlay model,and divides the satellite network into two categories:terrestrial network end users and satellite network end users.The energy efficiency,throughput,and signal-to-noise ratio(SINR)are deduced and analyzed.In this paper,we discuss the influence of various factors,such as transmit power,number of users,size of the protected area,and terminal position,on energy efficiency and SINR.A satellite-sharing scheme with a combination of the user location and an exclusion zone with high energy efficiency and anti-jamming capability is proposed to provide better communication quality for end users in integrated satellite and terrestrial networks.

面向天地一体化的确定性网络技术研究

卫星通信是未来通信领域的关键技术,低轨互联网星座是6G空天地海一体化网络的战略性基础设施,能够将当前通信网络扩展到全球近地区域。确定性网络技术是天基网络的重要技术之一,相比传统尽力而为的分组网络,确定性网络具有低时延、低抖动、低丢包率、高可靠的优势。概述了确定性网络当前的研究背景及现状,提出面向卫星通信的确定性网络架构,阐述了其关键技术,最后讨论了未来研究方向。

天地异构网络资源融合管理与智能调度技术

针对天地网络资源跨域分散、快速配置调度难、综合利用率低等问题,开展天地异构网络资源特性及融合模式分析,以网络性能优化为目标设计天地异构网络资源融合管理架构。针对资源的异质异构性进行网络资源的分类与虚拟化,针对不同的网络服务需求进行资源多维描述和子网构建,针对业务的动态变化进行虚拟化资源的智能分配与动态调整。采用上述技术实现了网络资源的协同运用与自主调优,通过全网资源的统一调度和智能分配提高了网络资源利用率,提升了网络服务质量。

铁路通信综合网络管理系统网络安全建设的研究

介绍铁路通信综合网管系统的建设背景、网络安全现状,并结合标准《铁路网络安全等级保护基本要求安全通用要求》(Q/CR 772-2020)、《铁路通信网络安全技术要求第1部分总体技术要求》(Q/CR 783.1-2021)对综合网管系统的的网络安全内容进行研究和分析,同时给出综合网管系统的网络安全建设模型建议。通过对综合网管系统网络安全建设的研究,为今后综合网管系统网络安全的有效防护工作提供参考。

银行业DAO数字化安全运营体系研究

在网络威胁呈爆发式增长的当下,随着业务模式数字化重塑与业务持续性增长,银行业面临因网络安全防线持续扩大所导致的安全设备冗杂、安全运营任务繁重、实战能力不足等问题.对银行业金融机构在安全运营中所面临的挑战进行分析,提出了融合平战一体化安全运营机制的银行业DAO(defence,ability and operation)数字化安全运营体系,重点研究纵深化防护基础、原子化能力中枢、数字化运营总台3层次架构,以及针对常态化、高强度、无间断防护目标的平战一体机制实施路径.

通信-感知-计算-存储深度融合下的无线资源管控

为满足多样化应用与极致性能需求,6G网络将提供通信、感知、计算与存储的融合服务,实现无缝泛在连接、全域精准感知的愿景。围绕通感算存深度融合下无线资源管控研究,首先简要介绍了通感算存融合网络的产生背景和无线资源管控研究现状,并对通感算存深度融合的灵活组网架构构建与关键技术进行了阐述。进一步地,为实现通感算存深度融合下的多域资源高效管控,对移动边缘计算网络和通感一体化网络的无线资源管控关键技术进行了分析讨论,并在此基础上探讨了通信、感知、计算与存储融合下的无线资源管控相关技术难点。

适应四网融合的市域(郊)铁路列控系统互联互通设计方案研究

近年来,“四网融合”发展已成为国家对轨道交通发展的重大战略,信号系统互联互通是实现“四网融合”的关键条件。从信号系统应用情况看,近期市域(郊)铁路信号系统列控制式大多数采用CTCS2+ATO,城市轨道交通线路信号系统主要采用CBTC,有必要对这两种列控系统互联互通设计方案进行研究。依托实际工程应用需求,采用重点内容举例和类比分析方法。首先,分析了互联互通土建及设备系统需要具备的工程条件,并对两种典型列控系统情况进行说明;之后,结合国内互联互通线路接驳及车站配线工程需求,阐述互联互通主要设计原则、制式转换最关键的共管区设计要点,以举例分析方式对停车和不停车切换的典型运营场景进行说明;最后,根据不同的设备设置方式,从调度指挥、车载列控和联锁设备几个方面,提出了完全独立和完全融合两种系统互联互通的建议方案;系统阐述互联互通需要具备的工程条件、共管区结合列控系统统一布置的设计要点,按两套车载设备同时在线和作业流程研究典型运营场景,提出了完全独立和完全融合两种方案的调度信息处理、车辆接口方式和联锁处理策略。

成德眉资经济圈轨道交通一体化发展对策研究

经济圈是都市圈发展进程中寻求更高标准、更高质量的城市形态,不仅能够更好地优化城市资源配置,还能够提升城市整体竞争力,促进经济的持续健康发展。成德眉资经济圈轨道交通一体化建设,不断促进多层次轨道交通初步成网,轨道交通半小时通勤圈和“两环三射”框架初步形成。通过阐释成德眉资经济圈轨道交通发展现状,从线网布局、运营管理、协同机制等方面,分析成德眉资经济圈轨道交通一体化发展存在的问题,提出完善轨道交通线网布局、加强运营管理一体化、强化组织协同管理等对策,以推动成德眉资经济圈协同发展。

基于四网融合的既有铁路市域化运营改造与发展研究——以西户铁路为例

针对四网融合背景下既有铁路市域化运营改造的相关问题,以西户铁路为例,研究既有铁路市域化运营改造的新思路与新模式。首先结合市域铁路的功能定位,在梳理既有铁路开行市域列车建设模式和运营特点的基础上,提出现阶段利用既有铁路开行市域列车存在技术标准不完善、线网融合程度低、客流强度不高、运营亏损严重等问题;然后以西户铁路开行市域列车为例进行研究,分析运输组织模式、客流特征、交通接驳方式等内容,深入探讨单线市域铁路客货混跑模式的适用性;最后论述市域铁路高质量发展的优化策略,提出统筹前期规划、优化交通衔接、提升运营效率、加快用地开发、打破管理壁垒等建议方案,为后续既有铁路改造提升提供参考。

跨学科融合视角下高校体育赛事网络舆情管理策略研究

随着新媒体技术的迅猛发展,高校体育赛事的网络舆情呈现出新的传播特点。基于传播学、社会心理学、信息技术等多学科理论,分析新媒体时代高校网络舆情的生成与传播、预警与防范、引导与应对。在此基础上,详细研究高校体育赛事网络舆情的传播特性,建立新的网络舆情管理模型,并提出了一系列防范和应对策略。通过这些措施,旨在有效应对新媒体时代高校体育赛事网络舆情的挑战,提升高校舆情管理的科学性和有效性。