LEO Network Research Articles

Load balancing routing algorithm based on extended link states in LEO constellation network

As an important part of satellite communication network, LEO satellite constellation network is one of the hot research directions. Since the nonuniform distribution of terrestrial services may cause inter-satellite link congestion, improving network load balancing performance has become one of the key issues that need to be solved for routing algorithms in LEO network. Therefore, by expanding the range of available paths and combining the congestion avoidance mechanism, a load balancing routing algorithm based on extended link states in LEO constellation network is proposed. Simulation results show that the algorithm achieves a balanced distribution of traffic load, reduces link congestion and packet loss rate, and improves throughput of LEO satellite network.

A Load Balancing Routing Strategy for LEO Satellite Network

The LEO network composed of massive satellite nodes is a hot research field at present. In such a network, the problem of load balancing should be reconsidered due to the large number of satellite nodes, the frequently changing topology, and the uneven distribution of global ground users. To solve such problem, a selective iterative Dijkstra algorithm (SIDA) is proposed to optimize the path finding process by reducing the reuse frequency of nodes. On the basis of SIDA, a selective split load balancing strategy (SSLB) is proposed to solve the link congestion problem in low latitude LEO network. SSLB is a distributed strategy, which diverts the traffic flow of congestion nodes to neighboring nodes. SSLB reduces the burden of neighbor nodes, which need the less demand of computing resources and signaling interaction. Simulation results show that SIDA reduces the number of congestion links and balances the load distribution, while SSLB can effectively suppress the number of new congestion links after traffic diversion. These algorithms provide a load balancing solution for LEO satellite network.

An Efficient Explicit Error Notification with Adaptive Packet Size Mechanism to Improve TCP Performance in LEO Network

An Efficient Explicit Error Notification with Adaptive Packet Size Mechanism to Improve TCP Performance in LEO Network

Network pruning for extending satellite service life in LEO satellite constellations

We address the problem of network pruning for extending the service life of satellites in LEO constellations. Satellites in LEO constellations can spend over 30 % of their time under the earth's umbra, time during which they are powered by batteries. While the batteries are recharged by solar energy, the depth of discharge they reach during eclipse significantly affects their lifetime--and by extension, the service life of the satellites themselves. For batteries of the type that power Iridium satellites, a 15 % increase to the depth of discharge can practically cut their service lives in half. In this paper, we present the design and evaluation of two forms of network pruning schemes that reduce the energy consumption of LEO satellite network. First, we propose a new lightweight traffic-agnostic metric for quantifiying the quality of a frugal topology, the Adequacy Index (ADI). After showing that the problem of minimizing the power consumption of a LEO network subject to a given ADI threshold is NP-hard, we propose heuristcs to solve it. Second, we propose traffic-aware metric for quantifiying the quality of a frugal topology, the maximum link utilization (MLU). Also, with the problem being NP-hard subject to a given MLU threshold, we propose heuristics to solve it. We evaluate both forms using realistic LEO topologies and traffic matrices. Results show that traffic-agnostic pruning and traffic-aware pruning can increase the satellite service life by as much as 85 and 80 %, respectively. This is accomplished by trading off very little in terms of average path length and congestion.

Addressing, Routing and Delivery Time Analysis of a LEO Satellite Network for Personal Communication System

Low Earth orbit satellite (LEO) networks become more important as demand for a truly global seamless personal communication system increases. To cover the whole earth, the inter links are very much essential. The LEO satellite network is connected by means of four point and six point cross-links. In this paper, the message delivery time of a low earth orbit satellite network was analyzed. The LEO network is the current trend in research and development to be included in the global PCS for supplementing terrestrial personal communication network and analyzed in this paper. The network is assumed to be regular and homogeneous. The addressing of the satellites was done by assuming the network in the form of Hexagonal meshes of six point cross-links. The continuous wrapping and broadcasting algorithm were also developed in this paper. The message delivery time was analyzed for the obtained LEO network for PCS.

Delivery time analysis of a low Earth orbit satellite network for seamless PCS

The message delivery time on a low Earth orbit (LEG) satellite network is analyzed. The LEO network is assumed to be seamless and virtual cut-through switching is proposed for use. Equations to calculate the message delivery time and the probability of a message being delivered successfully using no more than a time delay bound for LEO networks, varying in size and connectivity, are derived. The message delivery times of different LEO networks, varying in network connectivity, are compared. Numerical examples show that with the probability of successful delivery =0.99 and the probability of cut-through =0.5, an 8/spl times/8 LEO network with six crosslinks per node can deliver messages 40% faster than with four crosslinks per node for communicating satellites, separated by D hops, where D is the network diameter. >