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20 March 2022, Volume 3 Issue 1

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Special Issue: Frontier Technologies of Satellite Internet

Massive MIMO LEO Satellite Communications System

Kexin LI, Li YOU, Xiqi GAO

2022, 3(1):  2-8.  doi:10.11959/j.issn.2096-8930.2022001

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Extending massive multiple-input multiple-output (MIMO) technique to low earth orbit (LEO) satellite communication systems enables satellites to implement fl exible beamforming, which can make full use of the spatial degrees of freedom of massive MIMO and signifi cantly improve the spectral effi ciency and energy effi ciency of LEO satellite communication systems.Several related issues in massive MIMO-based LEO satellite communication systems were studied.The characteristics of massive MIMO LEO satellite channels were analyzed.The important diff erences between them and terrestrial wireless channels were revealed.With the aim of addressing the problems on channel information acquisition, multi-user transmission and user scheduling in massive MIMO LEO satellite communication, the main difficulties faced by the current work were discussed, and how to use the characteristics of massive MIMO LEO satellite channels to design tailored solutions with low implement complexity was conceived.

User Random Access Technology Based on Beam Hopping Satellite Communication System

Zixuan HUANG, Jiaxi ZHOU, Jing ZHANG, Zhengyu ZHANG

2022, 3(1):  9-17.  doi:10.11959/j.issn.2096-8930.2022002

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On the basis of geosynchronous earth orbit multi-beam satellite communication systems, this paper designed the process of user random access to the network and specifi c signaling interaction under the agile beam mechanism, and proposed the scheduling strategy and allocation scheme of the agile signaling beam.This scheme increased the fl exibility of access resource allocation under the premised of ensured that all users could accessed the network, eff ectively improved the utilization rate of satellite network resources.The request of user access to the satellite communication network belongs to the burst type, it is more suitable to use the random competition access, so this paper based on the general random competition access strategy, proposed an adaptive random competition access algorithm based on the heat value, based on the heat value predicted by the network side, the user selects diff erent random access strategies for access.Through the simulation and analysis of the optimization algorithm, it is proved that the algorithm could eff ectively reduced the probability of access collision under various network loads, so as to achieved the purpose of users quickly accessing the network.

Beam Hopping Beam Optimization and Resource Allocation Algorithm Based on Phased Array

Mengting HAO, Chen ZHANG, Gengxin ZHANG

2022, 3(1):  18-26.  doi:10.11959/j.issn.2096-8930.2022003

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Beam hopping technology can provide enough fl exibility and high resource utilization for satellite communication system, and shows good performance in broadband satellite communication system.However, the existing beam planning scheme of beam hopping technology is relatively fi xed and can not change with the change of service demand characteristics.For the situation of uneven distribution of user demand and scattered location, the advantages of beam hopping technology are diffi cult to play.To solve the above problems, a beam optimization method was proposed, which used the agility characteristics of phased array antenna to adjusted the size of beam according to the characteristics of service distribution, so as to made the service demand in each beam more balanced.On this basis, from the perspective of matching the demand with the actual transmission capacity, the minimization n-order diff erence objective function was established, the time slot resources allocated in each beam were solved by convex optimization algorithm, and the overall satisfaction and system delay of the system before and after beam optimization were compared.The simulation results showed that compared with the traditional beam planning scheme, the algorithm could improved the overall satisfaction of the system, reduced the system delay and improved the access success rate of the users.

Large Scale LEO Satellite Internet Routing Algorithm Based on Load Balancing

Yijie WANG, Wei ZHAO, Fei CHENG, Wen CHEN, Anjie CAO

2022, 3(1):  27-34.  doi:10.11959/j.issn.2096-8930.2022004

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The expanding market demand has set off an upsurge of large-scale LEO constellation deployment.With the characteristics of large bandwidth, low delay and continuous coverage, it provides broadband internet services for users all over the world.Aiming at the problem of congestion and packet loss caused by uneven network load, an adaptive large-scale LEO inter satellite routing algorithm based on load balancing was proposed.The algorithm divided the direction and level of candidate satellites according to the information obtained from small area detection, calculated the weight value according to diff erent partition results, and selected the next hop node with the highest level and the lowest weight value, carry out the same steps hop by hop until the data reaches the destination satellite node, fi nally formed a low delay path to realized low packet loss rate data transmission in the whole network.Through the simulation experiment, compared with the classical algorithm and the existing large-scale LEO satellite routing algorithm, the routing algorithm could eff ectively improved the routing performance of LEO large-scale satellite communication network and provided high-quality services for users.

Multilayer Satellite Network Dynamic Access Technology

Yunhan LI, Jianpeng MA, Xiongwen HE, Shun ZHANG, Hongyan LI

2022, 3(1):  35-43.  doi:10.11959/j.issn.2096-8930.2022005

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Using the characteristics of satellites in diff erent orbits to build a more effi cient multilayer satellite network has become a hotspot in satellite network research in recent years.Traditional satellite network access methods have been unable to meet the needs of multilayer satellite networks with low latency and fl exible access, so it is urgent to design an effi cient random dynamic access protocol for multilayer satellite networks.This paper fi rst summarized the traditional satellite network access technology, clarifi ed the development context of the satellite network random access protocol, and then proposed diff erent low latency for the two diff erent scenarios of ground station access to satellite and multilayer satellite network intersatellite access.The access method could provided a reference for the development of the dynamic access technology of the multilayer satellite network in the future.

Research on Resource Allocation of Satellite Internet Service Function Based on SDN/NFV

Meilin XU, Min JIA, Qing GUO

2022, 3(1):  44-49.  doi:10.11959/j.issn.2096-8930.2022006

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Software-defined networks and network function virtualization can effectively solve the problems of difficult management and control of large-scale networks and diffi culties in resource scheduling.Applying the software-defi ned network architecture model and network function virtualization technologies to the large-scale satellite internet can eff ectively solve some problems.This paper proposed a new SDN/NFV-based new satellite internet architecture, different satellite domains could be responsibled for different functions, inter-satellite and inter-domain could used SDN and NVF for eff ective collaboration, effi cient used of network resources, research and optimization of its service function resource allocation technology after VNF deployment, a simulated annealing algorithm based on resource awareness was proposed.Simulation results showed that this algorithm could effectively reduced the end-to-end delay and bandwidth consumption of SFC data fl ow during transmission, and could provided users with better services.

Research Prospect of Anti-Jamming Strategy for the Satellite Internet

Chen HAN, Aijun LIU, Kang AN

2022, 3(1):  50-55.  doi:10.11959/j.issn.2096-8930.2022007

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As an important infrastructure of the national information system, the satellite internet is of great signifi cance to the national security.Thus, it needs to ensure the validity and reliability of the data transmission in the hostile jamming environment.The threat of smart jamming and the limitation of classical link-layer anti-jamming methods give rise to the new demand of intelligent and networked antijamming solutions.In view of the structural characteristics of the satellite internet and the development trend of modern communication jamming technologies, this paper analyzed the basic architecture of intelligent and networked anti-jamming.Based on the closed-loop strategic of sense-learn-prediction-decision-feedback, intelligent and active anti-jamming decision was made to realized self-confi guration and self-optimization.Based on the cooperative communication between nodes, networked anti-jamming ability was improved by the means of topology control and reconstruction, adjacent resources reallocation, and traffi c load balancing.It provided certain theoretical support for the construction of anti-jamming strategy system to achieved the cross-layer optimization, multi-domain combination, and adaptive intelligence.

Studies

Hierarchical Intelligence Deployment Architecture for Satellite Internet

Zhe JI, Sheng WU, Wenbo WANG

2022, 3(1):  56-61.  doi:10.11959/j.issn.2096-8930.2022008

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To support the extensive traffi c anytime and anywhere, satellite networks have become a communication network infrastructure.It is challenging for the large-scale satellite internet to satisfy the requirements of the explosive increasing data traffi c and the delay-sensitive service delivery.The architecture characteristics of the satellite internet were discussed.Then, a hierarchical intelligence deployment architecture was proposed, and several intelligent training techniques that were highly possible for application in the architecture were given.Finally, some technical challenges for the proposed architecture were discussed from diff erent perspectives.

Digital Twin Satellite Internet: Architecture and Key Technologies

Yaoqi LIU, Hongguang LI, Yiqing ZHOU, Jinglin SHI, Yongtao SU, Jinxi QIAN

2022, 3(1):  62-71.  doi:10.11959/j.issn.2096-8930.2022009

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A digital twin satellite internet (DTSI) architecture was proposed, which provided support for the whole life cycle of satellite internet through the three-dimensional closed-loop mechanism of parallel twin, security endogenous and intelligent evolution.Then, the key problems and technologies of DTSI were discussed.Aiming at the complex and changeable satellite internet system, a standardized model processing and generation method based on mechanism and data driving was proposed.In the face of the data torrent formed by massive information and uneven distribution, a pool computing-storage strategy of three-level diversion strategy was proposed.In order to achieved high fi delity with the characteristics of the actual system, an intelligent orchestration and distributed heterogeneous processing platform was designed to classifi ed and quickly calculated diff erent models and events.In order to achieved high fi delity with the characteristics of the actual system, an intelligent orchestration and distributed heterogeneous processing platform was designed to classifi ed and quickly calculated diff erent models and events, the satellite internet twin cycle evolution system of observation-orientationdecision-act was formed, so as to realized the stable development of the whole life cycle of satellite internet.

Connection Planning Method Between LEO Communication Constellation and Earth Station

Shuge ZHAO, Xiaoyu LI, Qi LIU, Aijing WU, Jing WEI

2022, 3(1):  72-78.  doi:10.11959/j.issn.2096-8930.2022010

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A connection planning method between LEO communication constellation and earth station was proposed.Considering the large number of LEO communication constellation satellites, it is diffi cult to directly establish the connection planning method between LEO communication constellation and multiple earth stations.The connection planning method between single satellite and single earth station, the connection planning method between satellite constellation and single earth station, the connection planning method between satellite constellation and multiple earth stations were established.The former planning method is the basis of the latter planning method, which is the expansion of the former planning method, and fi nally forms a connection planning method between LEO communication constellation and multiple earth stations.A typical simulation example showed that in the process of connecting between the earth station and the satellite constellation, the elevation from the earth station to the satellite was not lower than the lower limit of the communication elevation.In the single connecting section between the earth station and the satellite, the variation trend of off -axis angle decreases fi rst and then increases.The connected satellites selected by the earth station showed the orbital plane switching and the sequential switching of satellites in an orbital plane, which indirectly verifi ed the correctness of the connection planning strategy.

Security Management Technology of Multilayer Satellite Internet Based on Blockchain

Ruijie ZHU, Yudong ZHANG, Yating WEI, Chao XI

2022, 3(1):  79-86.  doi:10.11959/j.issn.2096-8930.2022011

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Satellite internet have the advantages of wide coverage, low latency, large transmission capacity and no geographical infl uence.It can provide ubiquitous internet access services for users all over the world.However, the heterogeneity of satellite internet and ground network, the channel opening and node exposure of satellite internet will pose a security threat to network access and resource management.Aiming at the security problem of satellite internet, a multilayer satellite internet security management architecture based on blockchain was proposed.As a distributed ledger technology, blockchain uses chain data structure to verify and store data, and adopts encryption methods to maintain that data blocks cannot be tampered.Blockchain can realize network security access, trusted resource management, and provide information security protection for satellite internet.This paper improved the security of satellite internet by integrating blockchain technology with satellite internet.

Research on the Power Flux-Density at the Earth’s Surface Produced by Emissions from the Fixed Beam of NGSO Constellation System

Ying HUANG, Chen JIAN, Wei LI, Kang YAN

2022, 3(1):  87-93.  doi:10.11959/j.issn.2096-8930.2022012

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The power fl ux-density is an interference criterion for protecting terrestrial service systems from non-geostationary orbit (NGSO) constellation systems.Based on the defi nition of power fl ux density(PFD), a calculation method on the PFD produced by the emissions from the fi xed beam of NGSO constellation system was given.On the basis of describing the PFD constraint conditions of the NGSO fi xed-satellite service system given by ITU, a method for determining the limits of PFD from the NGSO constellation system was presented.Taking the Starlink system as the typical scenario, the PFD produced by telemetry, tracking, and control (TT＆amp;C) beam of the Starlink system was analyzed.The results showed that the analytical results of the given method were consistent with those of the Starlink system, and the PFD of TT＆amp;C beam in the 18.55-18.6 GHz frequency band exceeded the limit given in radio regulations.Under the current ITU framework, the number of the satellite constellation is a decisive factor for the legal use of the Ka band by NGSO constellation system.

Aviation Information Network Architecture Based on SDN/NFV

Xinkang SONG, Xiang WANG, Haotong FU, Shanghong ZHAO

2022, 3(1):  94-100.  doi:10.11959/j.issn.2096-8930.2022013

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As the key support for the emergence of cluster combat eff ectiveness, the design architecture of aviation information network will infl uence the combat mode in the aviation fi eld.Based on the future operational requirements of aviation cluster, the defi ciency of traditional aviation information network was introduced and the technical characteristics of SDN/NFV was analyzed.On this basis, combined SDN/NFV technology and aviation information network, an aviation information network architecture based on SDN/NFV was proposed, and its components were briefl y described.The future research directions and challenges of aviation information network architecture based on SDN/NFV were summarized.It also explored the ability of establishing effi cient information exchange and fi ne-grained aggregation of resources in aviation information network, which provided reference for the development of aviation information network in the future.

Key Technologies of Wavelength Routing for Space-based Information Network

Xin LI, Yongjun LI, Cong PENG, Shanghong ZHAO

2022, 3(1):  101-107.  doi:10.11959/j.issn.2096-8930.2022014

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With the expansion of space exploration scope and the enrichment of exploration means, the number of users carried by space-based information networks has increased rapidly, and the types of services have been continuously updated.As a key technology of optical network, wavelength routing technology is of great signifi cance to improve wavelength utilization and ensure network service quality.Three typical wavelength routing methods of space-based information networks based on multi-service, dynamic characteristics and software defi nition were introduced.And the intelligent wavelength routing technology, hierarchical wavelength routing technology and multipath wavelength routing technology in space-based information networks were studied.The key technologies of wavelength routing in space-based Optical information networks were prospected.