Achieving maximum flow for Inter-planetary networks

Inter-planetary network (IPN) systems on earth and spacecrafts communicate with systems on other planets. Communications and data are often relayed and delivered by the IPN systems. Delay/Disruption Tolerant Networking (DTN) have several unique characteristic features with significant challenges such as intermittent link connectivity, long and variable propagation delays, link bandwidth asymmetry, high link error rates and Power constraints. It is vital to overcome these challenges to achieve maximum flow for IPN systems. The aim of this project is to address the issue of achieving maximum flow in Inter-planetary network. To tackle these issues, a DTN model as time aggregated graph (TAG) was proposed and a bidirectional storage transfer series was used to correlate various time intervals and aid in maximizing flow. Our results suggest that the maximum flow can be achieved by seeking an augmenting path, computing its maximum flow, and getting its residual network using an iterative approach. In future, we intend to investigate the increase in difficulty of achieving maximum flow.

Review on Free-Space Optical Communications for Delay and Disruption Tolerant Networks

The increase of data-rates that are provided by free-space optical (FSO) communications is essential in our data-driven society. When used in satellite and interplanetary networks, these optical links can ensure fast connections, yet they are susceptible to atmospheric disruptions and long orbital delays. The Delay and Disruption Tolerant Networking (DTN) architecture ensures a reliable connection between two end nodes, without the need for a direct connection. This can be an asset when used with FSO links, providing protocols that can handle the intermittent nature of the connection. This paper provides a review on the theoretical and state-of-the-art studies on FSO and DTN. The aim of this review is to provide motivation for the research of an optical wireless satellite network, with focus on the use of the Licklider Transmission Protocol. The assessment presented establishes the viability of these networks, providing many examples to rely on, and summarizing the most recent stage of the development of the technologies addressed.

Analysis of Information Interaction Efficiency in Low-Orbit Satellite Constellations

The objects of the research are networks and information interactions in low-orbit satellite constellations performing tasks of remote sensing of the Earth. Research of network creation questions in this case is a necessary condition as opportunities and efficiency of information interaction directly depend on opportunities of a network. DTN (Delay-and-Disruption Tolerant Networking) technology is a basis of the network creation and CGR (Contact Graph Routing) approach is a basis of message routing. DTN technology and CGR approach are originally developed and used to provide communication with spacecraft located in a deep space. Therefore, the article discusses issues and problems arising in the context of their use in relation to low-orbit satellite constellations. The purpose of the information interaction study is development of effective interaction schemes (protocols). In the paper, the schemes of information interaction that can be used by a group of satellites in case of autonomous planning are considered. Along with autonomous planning, the paper also considers information interaction that can be used to implement network control of a satellite constellation in the case of ground planning. The effectiveness of the information interaction schemes are assessed by efficiency of orders’ execution. Measurement of efficiency is estimated via simulation of the communication network and the corresponding scheme of information interaction.