NOMA Empowered Energy Efficient Data Collection and Wireless Power Transfer in Space-Air-Ground Integrated Networks

As the sixth generation network(6G)emerges,the Internet of remote things(IoRT)has become a critical issue.However,conventional terrestrial networks cannot meet the delay-sensitive data collection needs of IoRT networks,and the Space-Air-Ground integrated network(SAGIN)holds promise.We propose a novel setup that integrates non-orthogonal multiple access(NOMA)and wireless power transfer(WPT)to collect latency-sensitive data from IoRT networks.To extend the lifetime of devices,we aim to minimize the maximum energy consumption among all IoRT devices.Due to the coupling between variables,the resulting problem is non-convex.We first decouple the variables and split the original problem into four subproblems.Then,we propose an iterative algorithm to solve the corresponding subproblems based on successive convex approximation(SCA)techniques and slack variables.Finally,simulation results show that the NOMA strategy has a tremendous advantage over the OMA scheme in terms of network lifetime and energy efficiency,providing valuable insights.

Holistic Service-Based Architecture for Space-Air-Ground Integrated Network for 5G-Advanced and Beyond

The Service-based Architecture(SBA) is one of the key innovations of 5G architecture that leverage modularized, self-contained and independent services to provide flexible and cloud-native 5G network. In this paper, SBA for Space-Air-Ground Integrated Network(SAGIN) is investigated to enable the 5G integration deployment. This paper proposes a novel Holistic Service-based Architecture(H-SBA)for SAGIN of 5G-Advanced and beyond, i.e., 6G. The H-SBA introduces the concept of end-to-end servicebased architecture design. The "Network Function Service", introduced in 5G SBA, is extended from Control Plane to User Plane, from core network to access network. Based on H-SBA, the new generation of protocol design is proposed, which proposes to use IETF QUIC and SRv6 to substitute 5G HTTP/2.0 and GTP-U. Testing results show that new protocols can achieve low latency and high throughput, making them promising candidate for H-SBA.

Civil Aircraft Assisted Space-Air-Ground Integrated Networks: Architecture Design and Coverage Analysis

In this paper, we propose a novel AIenabled space-air-ground integrated networks(SAGIN). This new integrated networks architecture consists of LEO satellites and civil aircrafts carrying aerial base stations, called "civil aircraft assisted SAGIN(CAA-SAGIN)". The assistance of civil aircrafts can reduce the stress of satellite networks, improve the performance of SAGIN, decrease the construction cost and save space resources. Taking the Chinese mainland as an example, this paper has analyzed the distribution of civil aircrafts, and obtained the coverage characteristics of civil aircraft assisted networks(CAAN). Taking Starlink as the benchmark, this paper has calculated the service gap of CAAN, and designed the joint coverage constellation. The simulation results prove that the number of satellites in CAASAGIN can be greatly reduced with the assistance of civil aircrafts at the same data rate.

Three-Dimensional Cooperative Localization via Space-Air-Ground Integrated Networks

The space-air-ground integrated network(SAGIN)combines the superiority of the satellite,aerial,and ground communications,which is envisioned to provide high-precision positioning ability as well as seamless connectivity in the 5G and Beyond 5G(B5G)systems.In this paper,we propose a three-dimensional SAGIN localization scheme for ground agents utilizing multi-source information from satellites,base stations and unmanned aerial vehicles(UAVs).Based on the designed scheme,we derive the positioning performance bound and establish a distributed maximum likelihood algorithm to jointly estimate the positions and clock offsets of ground agents.Simulation results demonstrate the validity of the SAGIN localization scheme and reveal the effects of the number of satellites,the number of base stations,the number of UAVs and clock noise on positioning performance.

Service Customized Space-Air-Ground Integrated Network for Immersive Media: Architecture, Key Technologies, and Prospects

The space-air-ground integrated network(SAGIN) is regarded as the key approach to realize global coverage in future network and it reaches broad access for various services. Being the new paradigm of service, immersive media(IM) has attracted users’ attention for its virtualization, but it poses challenges to network performance, e.g. bandwidth, rate, latency. However, the SAGIN has limitations in supporting IM services, such as 4 K/8 K video, virtual reality, and interactive games. In this paper, a novel service customized SAGIN architecture for IM applications(SAG-IM) is proposed, which achieves content interactive and real-time communication among terminal users. State-of-the-art research is investigated in detail to facilitate the combination of SAGIN and service customized technology, which provides endto-end differentiated services for users. Besides, the functional components of SAG-IM contain the infrastructure layer, perception layer, intelligence layer, and application layer, reaching the capabilities of intelligent management of the network. Moreover, to provide IM content with ultra-high-definition and high frame rate for the optimal user experience, the promising key technologies on intelligent routing and delivery are discussed. The performance evaluation shows the superiority of SAG-IM in supporting IM service.Finally, the prospects in practical application are high-lighted.

Predictive Decision and Reliable Accessing for UAV Communication in Space-Air-Ground Integrated Networks

The cooperation of multiple Unmanned Aerial Vehicles(UAVs) has become a promising scenario in Space-Air-Ground Integrated Networks(SAGINs) recently due to their widespread applications,where wireless communication is a basic necessity and is normally categorized into control and nonpayload communication(CNPC) as well as payload communication. In this paper, we attempt to tackle two challenges of UAV communication respectively on establishing reliable CNPC links against the high mobility of UAVs as well as changeable communication conditions, and on offering dynamic resource optimization for Quality-of-Service(QoS) guaranteed payload communication with variable link connectivity. Firstly, we propose the concept of air controlling center(ACC), a virtual application equipped on the infrastructure in SAGINs, which can collect global information for estimating UAV trajectory and communication channels. We then introduce the knapsack problem for modelling resource optimization of UAV communication in order to provide optimal access points for both CNPC and payload communication. Meanwhile, using the air controlling information, predictive decision algorithm and handover strategy are introduced for the reliable connection with multiple access points. Simulation results demonstrate that our proposal ensures an approximate always-on reliable accessing of communication links and outperforms the existing methods against high mobility,sparse distribution, and physical obstacles.

Intelligent Passive Detection of Aerial Target in Space-Air-Ground Integrated Networks

Passive detection of moving target is an important part of intelligent surveillance. Satellite has the potential to play a key role in many applications of space-air-ground integrated networks(SAGIN). In this paper, we propose a novel intelligent passive detection method for aerial target based on reservoir computing networks. Specifically, delayed feedback networks are utilized to refine the direct signals from the satellite in the reference channels. In addition, the satellite direct wave interference in the monitoring channels adopts adaptive interference suppression using the minimum mean square error filter. Furthermore, we employ decoupling echo state networks to predict the clutter interference in the monitoring channels and construct the detection statistics accordingly. Finally, a multilayer perceptron is adopted to detect the echo signal after interference suppression. Extensive simulations is conducted to evaluate the performance of our proposed method. Results show that the detection probability is almost 100% when the signal-to-interference ratio of echo signal is-36 dB, which demonstrates that our proposed method achieves efficient passive detection for aerial targets in typical SAGIN scenarios.

ESMD-Flow: An Intelligent Flow Forwarding Scheme with Endogenous Security Based on Mimic Defense in Space-Air-Ground Integrated Network

The Space-Air-Ground Integrated Network(SAGIN) realizes the integration of space, air,and ground networks, obtaining the global communication coverage.Software-Defined Networking(SDN) architecture in SAGIN has become a promising solution to guarantee the Quality of Service(QoS).However, the current routing algorithms mainly focus on the QoS of the service, rarely considering the security requirement of flow. To realize the secure transmission of flows in SAGIN, we propose an intelligent flow forwarding scheme with endogenous security based on Mimic Defense(ESMD-Flow). In this scheme, SDN controller will evaluate the reliability of nodes and links, isolate malicious nodes based on the reliability evaluation value, and adapt multipath routing strategy to ensure that flows are always forwarded along the most reliable multiple paths. In addition, in order to meet the security requirement of flows, we introduce the programming data plane to design a multiprotocol forwarding strategy for realizing the multiprotocol dynamic forwarding of flows. ESMD-Flow can reduce the network attack surface and improve the secure transmission capability of flows by implementing multipath routing and multi-protocol hybrid forwarding mechanism. The extensive simulations demonstrate that ESMD-Flow can significantly improve the average path reliability for routing and increase the difficulty of network eavesdropping while improving the network throughput and reducing the average packet delay.

Software-Defined Space-Air-Ground Integrated Network Architecture with the Multi-Layer Satellite Backbone Network

Under the background of the rapid development of ground mobile communication,the advantages of high coverage,survivability,and flexibility of satellite communication provide air support to the construction of space information network.According to the requirements of the future space information communication,a software-defined Space-Air-Ground Integrated network architecture was proposed.It consisted of layered structure satellite backbone network,deep space communication network,the stratosphere communication network and the ground network.The Space-Air-Ground Integrated network was supported by the satellite backbone network.It provided data relay for the missions such as deep space exploration and controlled the deep-space spacecraft when needed.In addition,it safeguarded the anti-destructibility of stratospheric communication and assisted the stratosphere to supplement ground network communication.In this paper,algorithm requirements of the congestion control and routing of satellite backbone protocols for heterogeneous users’services were proposed.The algorithm requirements of distinguishing different service objects for the deep space communication and stratospheric communication network protocols were described.Considering the realistic demand for the dynamic coverage of the satellite backbone network and node cost,the multi-layer satellite backbone network architecture was constructed.On this basis,the proposed Software-defined Space-Air-Ground Integrated network architecture could be built as a large,scalable and efficient communication network that could be integrated into space,air,and ground.

A review of Space-Air-Ground integrated remote sensing techniques for atmospheric monitoring

Currently,the three-dimensional(3D)distribution and characteristics of air pollution cannot be understood based on the application of any single atmospheric monitoring technology.Long-term,high-precision and large-scale 3D atmospheric monitoring might become practical by combining heterogeneous modern technologies;for this purpose,the SpaceAir-Ground integrated system is a promising concept.In this system,optical remote sensing technologies employing fixed or mobile platforms are used as the main means for groundbased observations.Tethered balloons,unmanned aerial vehicles(UAV)and airborne platforms serve as the air-based observation segment.The final part,satellite remote sensing,corresponds to space-based observations.Aside from obtaining the 3D distribution of air pollution,research on emission estimation and pollution mechanisms has been extensively implemented based on the strengths of this system or some portion of it.Moreover,further research on the fusion of multi-source data,optimization of inversion algorithms,and coupling with atmospheric models is of great importance to the realization of this system.

铁路地质灾害勘察识别与监测预警

地质灾害对铁路建设、安全运营构成了极大威胁,“天空地”一体化综合勘察技术有效解决了地质灾害勘察识别难题。“天”基多源立体卫星遥感技术实现艰险复杂山区地质灾害的大范围精准判识,长时序InSAR与高精度GPS实现高陡岸坡的稳定性监测分析;“空”基真实感大场景、机载倾斜摄影和机载LiDAR扫描技术实现高植被覆盖区隐蔽性地质灾害判识;“地”基三维立体勘探技术获取岩土体结构、属性、参数;共同构建沟谷山地灾害链风险评价方案,为建设工程合理选址和工程设置提供依据。介绍地质灾害监测预警的方法、内容、技术和预警模型,对监测预警技术发展方向进行展望。

Space/Air Covert Communications:Potentials,Scenarios,and Key Technologies

Space/air communications have been envisioned as an essential part of the next-generation mobile communication networks for providing highquality global connectivity. However, the inherent broadcasting nature of wireless propagation environment and the broad coverage pose severe threats to the protection of private data. Emerging covert communications provides a promising solution to achieve robust communication security. Aiming at facilitating the practical implementation of covert communications in space/air networks, we present a tutorial overview of its potentials, scenarios, and key technologies. Specifically, first, the commonly used covertness constraint model, covert performance metrics, and potential application scenarios are briefly introduced. Then, several efficient methods that introduce uncertainty into the covert system are thoroughly summarized, followed by several critical enabling technologies, including joint resource allocation and deployment/trajectory design, multi-antenna and beamforming techniques, reconfigurable intelligent surface(RIS), and artificial intelligence algorithms. Finally, we highlight some open issues for future investigation.

卫星互联网赋能新型电力系统创新应用

卫星互联网是通过卫星规模化组网,以航天、通信、网络、数据等技术为支撑的全球全域全时新型网络信息基础设施。与传统卫星网络相比,具有广覆盖、低时延、高带宽、低成本等优势。通过剖析新型电力系统在广域覆盖、抗毁顽存、垂直应用等信息化能力建设方面的挑战,凝练高中低轨协同的卫星互联网内涵定义与能力特征,提出卫星互联网在电力规划、态势感知、巡视检修、防灾应急等业务领域赋能新型电力系统的实践路径。提出基于零信任的星地融合网络信息安全体系,为建设、运行及发展空天地全面一体、通导遥深度融合的新型电力系统提供基础参考,进一步提升新质生产力水平。

星空地井一体化探测技术体系在复杂地质条件场地调查中的应用

复杂地质条件下的场地调查往往受地形起伏、断裂构造复杂、水文地质条件变化剧烈、人类工程扰动强烈等因素影响,存在调查范围缺乏科学性、调查尺度与精度难以协同平衡导致总体工作量部署高而高风险区表征精度相对不足。本文通过融合“星空界”、“天空界”、“地表界”、“地下界”技术,在突破单一技术手段片面零散探测的基础上,强调空天地一体化与井下探测技术的有机融合,构建了星空地井一体化探测技术体系。该一体化探测技术在湖北典型污染场地地下水污染调查中得到了有效应用验证,具有全局性视野认知、自组织高效诊断识别、兼具大时空尺度风险筛查与场地尺度分层精细表征等技术优势。此外,采用该一体化探测技术体系在江西赣南边远山区找水打井与地下水源应急供水中得到了应用验证,从技术方法上克服了传统单一方法的不确定性,科学有效地提高了基岩山区水文地质调查找水的成功率与工作效率。地表界调查圈定找水靶区,论证地下水源找水井位;地下界探测应用落地,基岩山区水文地质钻探涌水量达120 m3/d,解决了赣南革命老区季节性缺水的实际问题。作为行业共性关键技术,星空地井一体化探测技术体系在生态环境、自然资源、水利巡查、应急救灾等业务领域应用前景广阔。未来在多技术方法融合、多元异质信息融合及项目应用落地方面有待进一步拓展,天空界无人机航测、地下界分层精细探测新技术新方法等尚需加强研发应用与技术协同。

无人机辅助智能边缘网络技术综述

简要介绍了无人机作为空基信息平台的主要应用场景,结合6G多接入网络和用户为中心网络架构,讨论了无人机在构建智能边缘网络中的重要作用。结合无人机平台在不同场景下的通、感、算能力特点,介绍无人机自组网、无人机通感一体化、无人机边缘计算等无人机辅助智能边缘网络关键技术。最后,围绕无人机在构建智能边缘网络过程中与无线接入网新技术结合时产生的新问题,探讨无人机通信信道建模、三维立体部署与路径规划、携能有限与续航问题、无人机网络安全、无人机集群异构网络融合等关键技术挑战和未来研究方向。

基于移动边缘计算的空天地一体化网络架构

下一代无线通信技术将通过支持智能交通、智能医疗、虚拟现实/增强等服务来提高用户的体验质量。这些新兴的服务通常都是计算密集型和时延敏感型的,必须满足严格的时延、能耗和可靠性要求,而基于云计算的服务难以满足这些要求。为了解决以上问题,提出移动边缘计算(Mobile Edge Computing,MEC)技术,解决将卸载请求回传到云计算中心所具有的高时延和高带宽消耗的问题。空天地一体化网络(Space-Air-Ground Integrated Network,SAGIN)作为6G的重要研究方向,可以弥补全球范围内的巨大覆盖缺口,受到广泛关注。通过将MEC技术、联邦学习技术和人工智能技术引入SAGIN,高效管理网络中海量、异构的资源,构建低时延、低能耗、高可靠性的SAGIN,以支持新兴的各种服务。

无人机协同空天地一体化战场信息采集策略研究

围绕空天地一体化战场信息采集场景,建立优化目标为最大化系统效率和性能的信道分配和设备匹配模型。针对信道分配和设备匹配决策变量具有相关和耦合性的特点,提出一种基于遗传算法和深度强化学习的两阶段资源分配(GD2A)算法。通过仿真验证,分析超参数对GD2A算法的性能和收敛速度的影响。对比实验表明,GD2A算法能在6G空天地异构网络中保障军事通信的可靠性和安全性,最大化系统效用。

面向无人作业的天空地协同网络:需求、挑战、技术变革机遇

在偏远、危险地区,机器人可感知环境、智能交互,协同完成复杂任务。以卫星和无人机为主体的天空地协同网络能够为这些机器人提供全域泛在、随遇接入的通信服务。首先,分析无人作业发展趋势和机器人通信需求。基于此,面向机器人通信的特点,建议跳出“信息传输管道”的传统视角,在支持信息传输的同时,关注信息的内容和价值。进一步综合考虑机器人通信中信息生成的动作及其反馈,提出潜在技术变革的切入点。具体地,从结构化通信资源配置、机器人行为调控和感-传-算-控闭环模型三个方面阐述维纳控制论启发的通信范式变革途径。

6G service-oriented space-air-ground integrated network: A survey

As an indispensable component of the emerging 6G networks,Space-Air-Ground Inte-grated Networks(SAGINs)are envisioned to provide ubiquitous network connectivity and services by integrating satellite networks,aerial networks,and terrestrial networks.In 6G SAGINs,a wide variety of network services with the features of diverse requirements,complex mobility,and multi-dimensional resources will pose great challenges to service provisioning,which urges the develop-ment of service-oriented SAGINs.In this paper,we conduct a comprehensive review of 6G SAGINs from a new perspective of service-oriented network.First,we present the requirements of service-oriented networks,and then propose a service-oriented SAGINs management architec-ture.Two categories of critical technologies are presented and discussed,i.e.,heterogeneous resource orchestration technologies and the cloud-edge synergy technologies,which facilitate the interoperability of different network segments and cooperatively orchestrate heterogeneous resources across different domains,according to the service features and requirements.In addition,the potential future research directions are also presented and discussed.

边坡全维度监测技术与模型试验研究

中国是世界上地质灾害最严重的国家之一,其中滑坡常年位于各类地质灾害首位,因此对滑坡灾害进行深层次的研究至关重要。边坡工程常常会受到人类工程活动与自然地质作用叠加效应的影响,从而增加了对边坡变形失稳机理的科学认知难度。为精准掌握边坡状态信息与变形失稳过程,可通过建立全维度的监测体系以实现边坡状态信息的动态解译与表征,据此获得更加精准、可靠、直观的边坡稳定性评价依据。文章围绕边坡破坏模式及典型边坡监测技术,在厘清边坡变形演化过程的基础上,对边坡“天—空—地—体”一体化监测技术体系进行了全面分析;概述性总结了基于DFOS的边坡监测技术,重点阐述了基于DFOS的边坡多源多场监测研究思路与实施路径;系统性梳理了基于典型监测技术与DFOS技术的边坡物理模型试验研究过程与结果,以期为开展边坡加固方案设计与防灾减灾控灾提供重要的参考依据。