Satellite Communications with 5G, B5G, and 6G: Challenges and Prospects

Satellite communications, pivotal for global connectivity, are increasingly converging with cutting-edge mobile networks, notably 5G, B5G, and 6G. This amalgamation heralds the promise of universal, high-velocity communication, yet it is not without its challenges. Paramount concerns encompass spectrum allocation, the harmonization of network architectures, and inherent latency issues in satellite transmissions. Potential mitigations, such as dynamic spectrum sharing and the deployment of edge computing, are explored as viable solutions. Looking ahead, the advent of quantum communications within satellite frameworks and the integration of AI spotlight promising research trajectories. These advancements aim to foster a seamless and synergistic coexistence between satellite communications and next-gen mobile networks.

System Integration of Terrestrial Mobile Communication and Satellite Communication——The Trends, Challenges and Key Technologies in B5G and 6G

Mobile communication standards have been developed into a new era of B5G and 6G.In recent years,low earth orbit(LEO)satellites and space Internet have become hot topics.The integrated satellite and terrestrial systems have been widely discussed by industries and academics,and even are expected to be applied in those huge constellations in construction.This paper points out the trends of two stages towards system integration of the terrestrial mobile communication and the satellite communications:to be compatible with 5G,and to be integrated within 6G.Based on analysis of the challenges of both stages,key technologies are thereafter analyzed in detail,covering both air interface currently discussed in 3GPP for B5G and also novel network architecture and related transmission technologies toward future 6G.

From Earth to Space:A First Deployment of 5G Core Network on Satellite

Recent developments in the aerospace industry have led to a dramatic reduction in the manufacturing and launch costs of low Earth orbit satellites.The new trend enables the paradigm shift of satelliteterrestrial integrated networks with global coverage.In particular,the integration of 5G communication systems and satellites has the potential to restructure nextgeneration mobile networks.By leveraging the network function virtualization and network slicing,the satellite 5G core networks will facilitate the coordination and management of network functions in satellite-terrestrial integrated networks.We are the first to deploy a 5G core network on a real-world satellite to investigate its feasibility.We conducted experiments to validate the satellite 5G core network functions.The validated procedures include registration and session setup procedures.The results show that the satellite 5G core network can function normally and generate correct signaling.

Study on Security of 5G and Satellite Converged Communication Network

The 5G and satellite converged communication network(5G SCCN)is an impor⁃tant component of the integration of satellite-terrestrial networks,the national science,and technology major projects towards 2030.Security is the key to ensuring its operation,but at present,the research in this area has just started in our country.Based on the network char⁃acteristics and security risks,we propose the security architecture of the 5G SCCN and sys⁃tematically sort out the key protection technologies and improvement directions.In particu⁃lar,unique thinking on the security of lightweight data communication and design reference for the 5G SCCN network architecture is presented.It is expected to provide a piece of refer⁃ence for the follow-up 5G SCCN security technology research,standard evolution,and indus⁃trialization.

Assimilation of GMS-5 satellite winds using nudging method with MM5

With the aid of Meteorological Information Composite and Processing System (MICAPS), satellite wind vectors derived from the Geostationary Meteorological Statellite-5 (GMS-5) and retrieved by National Satellite Meteorology Center of China (NSMC) can be obtained. Based on the nudging method built in the fifth-generation Mesoscale Model (MM5) of Pennsylvania State University and Na- tional Center for Atmospheric Research, a data preprocessor is developed to convert these satellite wind vectors to those with specified format required in MM5. To examine the data preprocessor and evaluate the impact of satellite winds from GMS-5 on MM5 simulations, a series of numerical experimental fore- casts consisting of four typhoon cases in 2002 are designed and implemented. The results show that the preprocessor can process satellite winds smoothly and MM5 model runs successfully with a little extra computational load during ingesting these winds, and that assimilation of satellite winds by MM5 nudging method can obviously improve typhoon track forecast but contributes a little to typhoon intensity forecast. The impact of the satellite winds depends heavily upon whether the typhoon bogussing scheme in MM5 was turned on or not. The data preprocessor developed in this paper not only can treat GMS-5 satellite winds but also has capability with little modification to process derived winds from other geostationary satellites.

Satellite E2E Network Slicing Based on 5G Technology

We investigate the design of satellite network slicing for the first time to provide customized services for the diversified applications,and propose a novel scheme for satellite end-to-end(E2E) network slicing based on 5G technology,which provides a view of common satellite network slicing and supports flexible network deployment between the satellite and the ground.Specifically,considering the limited satellite network resource and the characteristics of the satellite channel,we propose a novel satellite E2E network slicing architecture.Therein,the deployment of the network functions between the satellite and the ground is coordinately considered.Subsequently,the classification and the isolation technologies of satellite network sub-slices are proposed adaptively based on 5G technology to support resource allocation on demand.Then,we develop the management technologies for the satellite E2E network slicing including slicing key performance indicator(KPI) design,slicing deployment,and slicing management.Finally,the analysis of the challenges and future work shows the potential research in the future.

Challenges,Opportunities,and Future Research in the Integration of 5G/6G Networks,LEO Satellites,and IoT for Environmental Protection and Sustainable Development at ECSTAR

The rapid proliferation of connected IoT(Internet of Things)devices,along with the increasing demand for 5G mobile networks and ubiquitous high-speed connectivity,poses significant challenges in the telecommunications sector.To address these challenges,a comprehensive understanding of the integration of 5G/6G networks and LEO(Low Earth Orbit)satellite networks is required,forming the concept of“integrated networks”.Integration offers valuable advantages,including service continuity,wide-area coverage,and support for critical communications and emerging applications.This paper provides a high-level overview of the convergence of 5G/6G,LEO satellites,and IoT devices,shedding light on the technological challenges and standardization issues associated with the transition from 5G to 6G networks using NTNs(Non-Terrestrial Networks)based on LEO satellites.Furthermore,this research delves into the emerging social issues,potential possibilities,and the paradigm shift from the IoT to the IoI(Internet of Intelligence),which is poised to revolutionize the landscape of 6G wireless networks.By highlighting the interconnectedness of 5G/6G networks,LEO satellite systems,and IoT devices,it underscores the importance of leveraging these converging technologies to address environmental protection and achieve the United Nations SDGs(Sustainable Development Goals).In addition to providing valuable insights for readers seeking to comprehend the convergence of 5G/6G networks,LEO satellite systems,and IoT devices,this paper represents the outcomes of a comprehensive analysis conducted at the ECSTAR(Excellence Center of Space Technology and Research).Through an examination of technological challenges and advancements,it identifies future research directions and potential avenues for exploration at ECSTAR,thereby contributing to a broader understanding of integrated networks and their profound impact on future telecommunications systems.This research serves as a significant resource for advancing the knowledge and discourse surrounding the linkages between the convergence of these technologies,environmental protection,and the pursuit of the SDGs.

MISSION OBJECTIVES OF SJ-5 SATELLITE COMPLETELY ACHIEVED

The SJ-5 (Shijian-5) spacecraft is the first China-made satellite for scientific research with theCAS as the user. Blasting off from the TaiyuanSatellite Launch Center on May 10, l999, the SJ-5completed its main experimental tasks on scheduleafter a 90-day-long earth-orbit flight. The normaloperation of the satellite’s platform provided aguarantee for the smooth fulfillment of its mission.All payloads aboard the satellite were independent-

LoS MIMO Transmission for LEO Satellite Communication Systems

To provide global service with low latency, the broadband low earth orbits (LEO) satellite constellation based communication systems have become one of the focuses in academic and industry. To allow for wideband access for user links, the feeder link of LEO satellite is correspondingly required to support high throughput data communications. To this end, we propose to apply line-of-sight (LoS) multiple-input multiple-output (MIMO) transmission for the feeder link to achieve spatial multiplexing by optimizing the antenna arrangement. Unlike the LoS MIMO applications for static scenarios, the movement of LEO satellites make it impractical to adjust the optimal antenna separation for all possible satellite positions. To address this issue, we propose to design the antenna placement to maximize the ergodic channel capacity during the visible region of the ground station. We first derive the closed-form probability distribution of the satellite trajectory in visible region. Based on which the ergodic channel capacity can be then calculated numerically. The antenna placement can be further optimized to maximize the ergodic channel capacity. Numerical results verify the derived probability distribution of the satellite trajectory, and show that the proposed LoS MIMO scheme can significantly increase the ergodic channel capacity compared with the existing SISO one.

Determining the Rate of Salinity of Persian Gulf Waters with the Aid of Satellite Images and Least Squares Method

As yet various methods have been used for determining the salinity rate of seas and oceans water. The current method of determining salinity rate of seas water has been field examination of various points of sea and determining its salinity rate. In the last decade, remote sensing satellite images have had high capability in determining sea waters salinity rate. Regarding that the present methods in remote sensing depend on the studied regions, therefore, the necessity of customization of these methods is felt. Fresh water springs due to impact on water salinity and temperature and also the environment physics and density like sound velocity are very significant and since coasts and islands of Persian Gulf are considered among arid and semi-arid regions and lack drinking water, access to fresh water springs has more significance. After studies performed, preparation of salinity rate observations and catching two series of proper images for felid data for complete coverage of the region, preprocessing and calibration was performed. For this purpose in turning the acquired radiance to reflection, ENVI software was used. The histogram of calibrated shades of gray rates in images was specified, so that reflection of each sample can be extracted from images. In this paper, the rate of least method efficiency in determining salinity rate of Persian Gulf waters was examined and finally identifying fresh water pits using remote sensing technique was done. The obtained results in the least squares methods after combining various bands of image with each other specified that combining 4 bands of 2, 3, 5 and 7 has the least standard deviation rate with training data and test, which is equal to 0.385 and 0.991978.

Modeling and Characterization of Vegetation, Aquatic and Mineral Surfaces Using the Theory of Plausible and Paradoxical Reasoning from Satellite Images: Case of the Toumodi-Yamoussoukro-Tiébissou Zone in V Baoulé(Côte d’Ivoire)

In this paper, the theory of plausible and paradoxical reasoning of Dezert- Smarandache (DSmT) is used to take into account the paradoxical charac-ter through the intersections of vegetation, aquatic and mineral surfaces. In order to do this, we developed a classification model of pixels by aggregating information using the DSmT theory based on the PCR5 rule using the ∩NDVI, ∩MNDWI and ∩NDBaI spectral indices obtained from the ASTER satellite images. On the qualitative level, the model produced three simple classes for certain knowledge (E, V, M) and eight composite classes including two union classes characterizing partial ignorance ({E,V}, {M,V}) and six classes of intersection of which three classes of simple intersection (E∩V, M∩V, E∩M) and three classes of composite intersection (E∩{M,V}, M∩{E,V}, V∩{E,M}), which represent paradoxes. This model was validated with an average rate of 93.34% for the well-classified pixels and a compliance rate of the entities in the field of 96.37%. Thus, the model 1 retained provides 84.98% for the simple classes against 15.02% for the composite classes.

基于GF-5高光谱遥感的农作物种植结构监测研究

光学影像在农作物种植结构分类研究中因光谱波段数量有限,对于外在特征差异较小的农作物识别与分类存在一定的局限性。本研究探索利用高分五号(GF-5)高光谱卫星影像的丰富光谱信息,根据不同类别农作物对不同谱段反射光谱曲线差异性进行分类,结果表明农作物种植结构分类效果良好。

用GMS-5气象卫星资料遥感监测白天雾的研究

用日本 GMS- 5静止气象卫星的可见光通道和长波红外通道的资料 ,采用多通道合成和图像增强技术生成云雾彩色图像 ,分析了云雾的纹理特征、运动规律和消散规律 ,探讨了白天雾和低层云的遥感监测和识别方法 。

利用GMS-5红外资料进行云的分类识别

利用GMS 5 3个红外通道 (2个分裂窗区通道和 1个水汽通道 )的亮温资料 ,依据各种云不同的辐射特征对其进行分类 ,由此识别出积雨云 (Cb)、浓积云 (Cg)、卷云 (Ci)、积云 (Cu)、中云(Cm)、密云 (Dense)等 6种主要云类以及雾 (Fog)和晴空区域。结合安徽寿县地面观测基准站 1998年 6、7月份的地面观测资料 ,对分类结果进行了检验 ,得到了较为令人满意的结果 ,准确率接近70 %。

近地面PM_(2.5)浓度卫星反演研究进展

卫星反演近地面PM2.5浓度是大气科学研究的重要领域之一。本文从卫星AOD数据来源、反演算法和建立AOD-PM2.5反演模型等关键技术阐述了近地面PM2.5浓度卫星反演的研究进展以及存在的问题。针对数学统计法、物理订正法和耦合反演法,分别分析了三种方法的优缺点,并重点分析了物理订正法中的湿度订正和垂直订正技术。

GMS-5红外资料反演大气可降水量

建立了用ＧＭＳ－５红外亮温资料反演大气可降水量的分裂窗统计法。初步试验结果表明，分裂窗统计法反演的ＲＭＳ误差为０．３７ｇｃｍ－２。优于用ＧＯＥＳ的分裂窗资料反演可降水量的精度，达到或超过用ＡＶＨＲＲ分裂窗资料反演可降水量的精度。对月平均水汽分布的比较显示，反演可降水量分布与实际探空资料获得的分布是一致的。

国产GF-5高光谱遥感在铀矿找矿中的应用——以甘肃省龙首山地区为例

GF-5观测卫星拥有着330个谱段的高光谱分辨率遥感数据,是我国2019年自主研发的首颗高光谱综合观测卫星。基于GF-5卫星开展的地质找矿应用的研究较少,文章选取了基岩裸露程度高、铀成矿地质条件优越的甘肃省龙首山铀成矿带作为GF-5高光谱遥感适宜性和可行性验证研究区,开展了数据预处理研究,构建了GF-5高光谱数据处理方法和流程,运用MNF算法、PPI算法,结合SAM光谱角填图技术,在研究区内共提取到包括钠长石、赤铁矿、高岭石、石英(硅化)、绿泥石和方解石在内的6种蚀变矿物。提取的蚀变矿物空间展布与区内铀矿(化)点、断裂构造和龙首山岩群分布特征关系密切,并通过开展地面光谱测量验证了蚀变矿物提取结果的可靠性。基于研究成果,丰富了GF-5高光谱的铀矿找矿工作思路,为国产GF-5高光谱遥感应用于地质找矿提供了参考。

基于SPOT-5卫星影像的灌区作物识别

高分辨率卫星影像是作物精确分类和评估的重要数据源,在农作物种植规划、估产等领域具有重要的应用价值。本研究利用分辨率为2.5m的SPOT-5影像分析张掖市盈科灌区的作物分布状况,同时分别生成分辨率为10和30m的影像,用于尺度验证。最终得到研究区作物分类图,所用方法主要有最小距离法、马氏距离、最大似然法、光谱角制图仪(SAM)和支持向量机(SVM)。Kappa系数分析表明,最大似然法和SVM的分类效果好于其它分类器,分别为0.871 9和0.862 5,但这两种方法的统计量无明显区别;分类图精度评价表明,基于最大似然法的分类图总体精度最高,为90.6%;随像元空间尺度的增加,分类精度未产生明显变化。研究结果表明,最大似然法和SVM技术可以与SPOT-5影像结合,用于作物类型识别和作物面积估算。

用GMS-5对东亚地区对流层高层水汽的研究

大气中的水汽是气候变化中至关重要的影响因子,对流层高层的水汽对地气系统的辐射能量平衡尤为重要。卫星观测极大地弥补了常规探空手段对高空低温低湿条件下的水汽探测能力的不足。6.7μm水汽通道是被广泛用于大气水汽反演的卫星通道之一,Soden等(1993)提出一个用该通道亮温反演对流层高层水汽的方法。将这一方法应用于日本GMS 5静止卫星的水汽云图,得到东亚地区中无云区域与水汽云图具有相同时空分辨率的对流层高层水汽分布。反演得到的月平均对流层高层平均相对湿度与NCEP分析资料给出的平均相对湿度具有较好的一致性。根据1996—2002年的GMS 5水汽通道亮温资料得到东亚地区对流层高层水汽的典型时、空分布形式。随卫星观测记录的延续,反演得到的长时间序列的对流层高层相对湿度资料将为水循环的研究和水汽对气候变化响应和反馈的研究提供有力依据。

Meteosat-5卫星HRI资料接收处理系统研制

为了接收定位于６３°Ｅ的Ｍｅｔｅｏｓａｔ－５ 卫星ＨＲＩ高分辨资料，研制了ＨＲＩ接收处理系统并投入业务运行，接收的资料通过９２１０ ＶＳＡＴ 卫星通信网向用户广播．本文介绍了系统组成、研制内容和实验结果．