近年来，低轨卫星通信系统凭借全球覆盖和灵活部署等优势，受到学术界和工业界的广泛关注。在低轨卫星通信系统中，星间链路将多个卫星连接成一个动态网络，如何降低网络的通信时延是一个亟待解决的研究问题。针对Walker极轨道星座的反向缝建链问题，提出一种星形交叉循环建链策略（SCLBS）。将反向缝两侧的轨道划分为多个交叉建链区，通过动态建立星间链路，优化传输时延，为极轨道反向缝提供稳定的建链方案。在飞机和船舶等实际业务场景下对SCLBS进行仿真，结果表明与基于最近卫星准则和基于最长可视时间准则等建链策略相比，SCLBS能够有效降低30%~60%的传输时延，明显提升系统性能。
Recently, the low earth orbit (LEO) satellite communication system has received wide attention from academia and industry, due to its global coverage and flexible construction. In the LEO satellite communication system, satellites are connected to a dynamic network through the inter-satellite link (ISL). How to reduce the communication delay of the network is an urgent research problem to be solved. For the problem of cross seam link-building of the Walker polar orbit constellation, this paper proposes a star cross looping link-building strategy (SCLBS). SCLBS divides the orbits into multiple cross link-building areas on both sides of cross seam and the transmission delay can be optimized by dynamically established ISL, providing a stable link-building scheme for polar orbit cross seam. SCLBS is applied to actual business scenarios such as the airplane and ship, and the test results show that SCLBS can effectively reduce the transmission delay by 30% to 60% compared with the link-building strategies based on the nearest satellite criterion and the longest visible time criterion, and significantly improve system performance.
[1] 3GPP. TR 38.821 v16.0.0:Solution for NR to support non-terrestrial networks (NTN)[R/OL]. (2020-01-16)[2021-02-05]. https://www.3gpp.org/ftp/Specs/archive/38_series/38.821/38821-g00.zip.
[2] 刘沛龙, 陈宏宇, 魏松杰, 等. LEO卫星网络海量遥感数据下行的负载均衡多径路由算法[J]. 通信学报, 2017, 38(S1):135-142.
[3] Tian F, Huang L L, Liang G, et al. An efficient resource allocation mechanism for beam-hopping based LEO satellite communication system[C]//2019 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB). Jeju, Korea (South):IEEE, 2019:1-5.
[4] 刘婉莹, 夏师懿, 姜泉江, 等. 低轨卫星网络基于跳波束的资源调度算法[J]. 中国科学院大学学报, 2020, 37(06):805-813.
[5] Ferreira A, Galtier J, Penna P. Topological design, routing, and handover in satellite networks[M]//Wiley Series on Parallel and Distributed Computing. New York, USA:John Wiley & Sons, 2002:473-493.
[6] De Sanctis M, Cianca E, Ruggieri M. Ip-based routing algorithms for Leo satellite networks in near-polar orbits[C]//2003 IEEE Aerospace Conference Proceedings (Cat. No.03TH8652). Big Sky, MT, USA:IEEE, 2003:1273-1280.
[7] Ekici E, Akyildiz I F, Bender M D. A distributed routing algorithm for datagram traffic in LEO satellite networks[J]. IEEE/ACM Transactions on Networking, 2001, 9(2):137-147.
[8] Gavish B, Kalvenes J. The impact of intersatellite communication links on LEOS performance[J]. Telecommunication Systems, 1997, 8(2/3/4):159-190.
[9] Yeo B S, Turner L F. An approach to the modeling of counter-rotating seam communication links for LEO satellite systems[C]//2004 IEEE Wireless Communications and Networking Conference (IEEE Cat. No.04TH8733). Atlanta, GA, USA:IEEE, 2004:2016-2020.
[10] Guo Z, Yan Z. A weighted semi-distributed routing algorithm for LEO satellite networks[J]. Journal of Network and Computer Applications, 2015, 58:1-11.
[11] Jamalipour A, Chen J. Performance study of handoff schemes in broadband ATM mobile satellite networks[C]//ATM 2000. Proceedings of the IEEE Conference on High Performance Switching and Routing (Cat. No.00TH8485). Heidelberg, Germany:IEEE, 2000:501-508.
[12] Gkizeli M, Tafazolli R, Evans B. Performance analysis of handover mechanisms for non-GEO satellite diversity based systems[C]//GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270). San Antonio, TX, USA:IEEE, 2001:2744-2748.
[13] 卢勇, 赵有健, 孙富春, 等. 卫星网络路由技术[J]. 软件学报, 2014, 25(05):1085-1100.
[14] Tang F L, Zhang H T, Yang L T. Multipath cooperative routing with efficient acknowledgement for LEO satellite networks[J]. IEEE Transactions on Mobile Computing, 2018, 18(1):179-192.
[15] Xia S Y, Jiang Q J, Zou C, et al. Beam coverage comparison of LEO satellite systems based on user diversification[J]. IEEE Access, 2019, 7:181656-181667.
[16] Chen L, Zhang Q, Li M L, et al. Joint topology control and routing in IEEE 802.11-based multiradio multichannel mesh networks[J]. IEEE Transactions on Vehicular Technology, 2007, 56(5):3123-3136.
[17] Qi S Y, Zhang Q, Xin X J, et al. Research on scanning method in satellite laser communication[C]//201918th International Conference on Optical Communications and Networks (ICOCN). Huangshan, China:IEEE, 2019:1-3.
