Capacity Analysis Of The Low-orbit Satellite Network

The low-orbit satellite network with the advantages of low latency,wide coverage,low cost,and broad bandwidth is ushering in a new upsurge of development and has broad application prospects in the Internet of Things,personal mobile communications and other fields.Judging from low-orbit satellite networks that have been released by various countries,the large-scale development of low-orbit satellite networks has become a trend.Although the scale of the low-orbit satellite network continues to expand,the relationship between the capacity of the low-orbit satellite network and network scale,node/ link reliability,business distribution is still unclear,which affects the top-level design of the network and causes the risk of network resources waste or insufficient network service capability.To this end,this paper mainly investigates the maximum data rate that can be injected into the low-orbit satellite network,i.e.the network throughput capacity,and explores the relationship between the capacity of the low-orbit satellite network and network scale,node/ link reliability,and network business distribution.The main innovations and contributions of this paper are as follows:1.The mathematical relationship between network scale and network capacity is modeled.The law of network capacity changing with the number of orbits N,the number of single-orbit satellites M,and the maximum feasible transmission rate of the link B_l is revealed.The restriction mechanism of network topology on network capacity is discovered,and the optimal network topology configuration that maximizes the network capacity is presented.Two classic capacity calculation methods,namely maximum flow minimum cut and average path hop,are used to verify the above theories at the same time.The results show that the network capacity increases with the increase of the maximum feasible transmission rate of the link.The single-satellite capacity decreases as the network size increases,and is approximately proportional to 1/(NM)^1/2.The network capacity increases as the network scale increases,and is approximately proportional to (NM)^1/2.2.The mathematical relationship between node/ link reliability and network capacity is modeled,and the mechanism of the effect of node/ link failure probability on network capacity is revealed.The deployment strategy of network scale that maximizes network capacity under the node/ link reliability constraints is given,and the relationship between node reliability and the network scale for a given network capacity is revealed.The results show that when a given network capacity requirement is met,as the network scale continues to increase,the network's requirements for node reliability continue to decrease,and the gradient of decline continues to decrease.3.The mathematical relationship between network business distribution and network capacity is modeled.The law of network capacity changing with network business distribution is revealed.The capacity of the low-orbit satellite network in the case of unsaturated service is analyzed based on the method of average path hop.The unity of the theories with unsaturated and saturated services is verified.In addition,the analysis method of the network business distribution that maximizes network capacity for a given network scale is presented.