Download or read book Performance Analysis of Dynamic Routing Protocols in a Low Earth Orbit Satellite Data Network written by Richard F. Janoso and published by . This book was released on 1996-12-01 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern warfare is placing an increasing reliance on global communications. Currently under development are several Low Earth Orbit (LEO) satellite systems that propose to deliver voice and data traffic to subscribers anywhere on the globe. However, very little is known about the performance of conventional routing protocols under orbital conditions where the topology changes on a scale of minutes rather than days. This thesis compares two routing protocols in a LEO environment. One (Extended Bellman-Ford) is a conventional terrestrial routing protocol, while the other (Darting) is a new protocol which has been proposed as suitable for use in LEO networks. These protocols are compared via computer simulation in two of the proposed LEO systems (Globalstar and Iridium), under various traffic intensities. Comparative measures of packet delay, convergence speed, and protocol overhead are made It was found both protocols were roughly equivalent in end-to-end delay characteristics, though the Darting protocol had a much higher overhead load and demonstrated higher instability at network update periods. For example, while steady state end-to- end delays were within a few milliseconds, in one case Darting showed an increase of 764% in convergence time over Extended Bellman-Ford with an increase of 149% in overhead. Over all cases, Darting required an average of 72.1% more overhead than Extended Bellman-Ford to perform the same work. Darting was handicapped by its strong correlation between data traffic and protocol overhead. Modifications to reduce this overhead would result in much closer performance.

Download or read book A Performance Analysis of Dynamic Routing Algorithms in an IRIDIUM Like Low Earth Orbit Satellite System written by Stephen R. Pratt and published by . This book was released on 1999-03-01 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research presents a first of its kind comparative analysis of the Extended Bellman-Ford and Darting algorithms, using the Iridium low earth orbit (LEO) satellite system configuration for the simulation environment. The algorithms are compared to one another via discrete-event computer simulation and evaluated based on their ability to route real-time voice communications under low, medium, and high network loading conditions. The algorithms' ability to meet real-time voice constraints is evaluated with a full and degraded satellite constellation using an algorithmic satellite removal method. The investigation results indicate that both algorithms are suitable for use in a LEO environment and are capable of meeting the real-time voice communications requirements as long as a load-balancing mechanism is in place to route traffic around heavily loaded satellites. The results also indicate that the Iridium system is robust, capable of meeting the real-time voice constraints even when the constellation is degraded.

Download or read book A Performance Analysis of Dynamic Routing Algorithms in an Iridium like Low Earth Orbit Satellite System written by Stephen R. Pratt (CAPT, USAF.) and published by . This book was released on 1999 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Analysis of Protocol Independent Multicasting Dense Mode in Low Earth Orbit Satellite Networks written by Mark D. Saeger and published by . This book was released on 2003-03-01 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research explored the implementation of Protocol Independent Multicasting - Dense Mode (PIM-DM) in a LEO satellite constellation. PIM-DM is a terrestrial protocol for distributing traffic efficiently between subscriber nodes by combining data streams into a tree-based structure, spreading from the root of the tree to the branches. Using this structure, a minimum number of connections are required to transfer data, decreasing the load on intermediate satellite routers. The PIM-DM protocol was developed for terrestrial systems and this research implemented an adaptation of this protocol in a satellite system. This research examined the PIM-DM performance characteristics which were compared to earlier work for On- Demand Multicast Routing Protocol (ODMRP) and Distance Vector Multicasting Routing Protocol (DVMRP) - all in a LEO satellite network environment. Experimental results show that PIM-DM is extremely scalable and has equivalent performance across diverse workloads. Three performance metrics are used to determine protocol performance in the dynamic LEO satellite environment, including Data-to- Overhead ratio, Received-to-Sent ratio, and End- to-End Delay. The OPNET(registered) simulations show that the PIM-DM Data-to- Overhead ratio is approximately 80% and the protocol reliability is extremely high, achieving a Receive-to-Sent ratio of 99.98% across all loading levels. Finally, the PIM-DM protocol introduces minimal delay, exhibiting an average End-to-End Delay of approximately 76 ms; this is well within the time necessary to support real-time communications. Though fundamental differences between the DVMRP, ODMRP, and PIM-DM implementations precluded a direct comparison for each experiment, by comparing average values, PIM-DM generally provides equivalent or better performance.

Download or read book Routing and Quality of Service in Broadband LEO Satellite Networks written by Hoang Nam Nguyen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Routing and Quality-of-Service in Broadband LEO Satellite Networks describes mechanisms for supporting Quality-of-Service (QoS) strategies that consider properties of low earth orbit satellite networks and their effects on link handover. A graph model representing the dynamic topology of a satellite constellation is introduced based on a new parameter, lifetime. Novel routing and resource reservation algorithms as well as connection admission control strategies are proposed to minimize the handover blocking probability while maintaining QoS requirements. The author also discusses the roles of satellites in an all-IP mobile network architecture and the problems of mobility, QoS provisioning, and routing. This work will be of particular interest to researchers and professionals working on mobility networking in next generation networks.

Download or read book Satellite Personal Communications for Future generation Systems written by Enrico Del Re and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: Consisting of selected technical contributions to the European Project COST252, this volume provides many innovative results which can be the basis for new global telecommunications systems providing multimedia services at high rates. It also presents new perspectives on communications problems in various areas.

Download or read book Congestion Control and Routing Over Satellite Networks written by Jinhua Cao and published by . This book was released on 2010 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satellite networks and transmissions find their application in fields of computer communications, telephone communications, television broadcasting, transportation, space situational awareness systems and so on. This thesis mainly focuses on two networking issues affecting satellite networking: network congestion control and network routing optimization. Congestion, which leads to long queueing delays, packet losses or both, is a networking problem that has drawn the attention of many researchers. The goal of congestion control mechanisms is to ensure high bandwidth utilization while avoiding network congestion by regulating the rate at which traffic sources inject packets into a network. In this thesis, we propose a stable congestion controller using data-driven, safe switching control theory to improve the dynamic performance of satellite Transmission Control Protocol/Active Queue Management (TCP/AQM) networks. First, the stable region of the Proportional-Integral (PI) parameters for a nominal model is explored. Then, a PI controller, whose parameters are adaptively tuned by switching among members of a given candidate set, using observed plant data, is presented and compared with some classical AQM policy examples, such as Random Early Detection (RED) and fixed PI control. A new cost detectable switching law with an interval cost function switching algorithm, which improves the performance and also saves the computational cost, is developed and compared with a law commonly used in the switching control literature. Finite-gain stability of the system is proved. A fuzzy logic PI controller is incorporated as a special candidate to achieve good performance at all nominal points with the available set of candidate controllers. Simulations are presented to validate the theory. An effocient routing algorithm plays a key role in optimizing network resources. In this thesis, we briefly analyze Low Earth Orbit (LEO) satellite networks, review the Cross Entropy (CE) method and then develop a novel on-demand routing system named Cross Entropy Accelerated Ant Routing System (CEAARS) for regular constellation LEO satellite networks. By implementing simulations on an Iridium-like satellite network, we compare the proposed CEAARS algorithm with the two approaches to adaptive routing protocols on the Internet: distance-vector (DV) and link-state (LS), as well as with the original Cross Entropy Ant Routing System (CEARS). DV algorithms are based on distributed Bellman Ford algorithm, and LS algorithms are implementation of Dijkstras single source shortest path. The results show that CEAARS not only remarkably improves the convergence speed of achieving optimal or suboptimal paths, but also reduces the number of overhead ants (management packets).

Download or read book Performance Analysis of the Transmission Control Protocol Over Low Earth Orbit Satellite Communication Systems written by Rahul Sangal and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Routing Algorithm Analysis for a Nanosatellite Constellation in Low Earth Orbit written by S. McKenzie-Picot and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper examines possible routing algorithms in a proposed network of nanosatellites with the goal of finding networking methods that could be effectively used in a dynamic environment with limited computing power. Three routing algorithms were created and their performance was compared to Dijkstra's shortest path algorithm. The chaos method transmitted to accessible satellites at random. The minimum distance method transmitted to the closest unused satellite. The grouping method grouped satellites by their physical position in the network and made transmission decisions based on these groups. Each algorithm was run for every possible combination of source and destination satellite in the network to find average transmission times, distances, and number of network nodes used. It was found that the grouping method had performance comparable to Dijkstra's algorithm while requiring less computing power, and was acceptable for high-speed network requirements, such as live voice. The chaos method was acceptable for lower speed applications and for satellites that had little computing power, and the minimum distance method improved on chaos method with little extra computing power required.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1990 with total page 996 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Satellite Network Robust QoS aware Routing written by Fei Long and published by Springer. This book was released on 2014-04-28 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satellite Network Robust QoS-aware Routing presents a novel routing strategy for satellite networks. This strategy is useful for the design of multi-layered satellite networks as it can greatly reduce the number of time slots in one system cycle. The traffic prediction and engineering approaches make the system robust so that the traffic spikes can be handled effectively. The multi-QoS optimization routing algorithm can satisfy various potential user requirements. Clear and sufficient illustrations are also presented in the book. As the chapters cover the above topics independently, readers from different research backgrounds in constellation design, multi-QoS routing, and traffic engineering can benefit from the book. Fei Long is a senior engineer at Beijing R&D Center of 54th Research Institute of China Electronics Technology Group Corporation.

Download or read book Multicast Routing Algorithms and Failure Analyses for Low Earth Orbit Satellite Communication Networks written by Jae Soong Lee and published by . This book was released on 2002-08-01 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the rapidly changing environment of mobile communications, the importance of the mobile satellite (e,g,, low earth orbit satellites (LEOsats)) networks will increase due to their global visibility and connection. Multicasting is an effective communication method in terms of frequency spectrum usage for a LEO network. It is devised to provide lower network traffic (i,e,, one-to-many transmissions). This research examines the system performance of two dissimilar terrestrially-based multicasting protocols: the Distance Vector Multicast Routing Protocol (DVMRP) and the On Demand Multicast Routing Protocol (ODMRP). These two protocols are simulated in large group membership density and in the presence of satellite failures. Two different algorithms are developed and used to select critical satellites for degrading a LEO network constellation. The simulation results show that the ODMRP protocol successfully reconfigured routes in large group membership density areas and in satellite failure conditions. Results also show that the ODMRP provided reliable packet delivery. However, ODMRP showed an enormous end-to-end delay in severe satellite failure conditions. This result is attributable to the delayed route refreshing procedure of ODMRP. In contrast, the DVMRP suffered from broken routes and complexity in the large group membership density and in satellite failure conditions. It had a smaller packet delivery ratio than the ODMRP (approximately 85,5% versus 98,9% for the 80 user case). The DVMRP showed scalable and stable end-to-end delay under multiple failed satellite conditions. The large group membership density and the multiple satellite failure conditions provide a more complete assessment for these two protocols.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1984 with total page 1294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Communications Signal Processing and Systems written by Qilian Liang and published by Springer Nature. This book was released on 2020-04-04 with total page 2720 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together papers from the 2019 International Conference on Communications, Signal Processing, and Systems, which was held in Urumqi, China, on July 20–22, 2019. Presenting the latest developments and discussing the interactions and links between these multidisciplinary fields, the book spans topics ranging from communications to signal processing and systems. It is chiefly intended for undergraduate and graduate students in electrical engineering, computer science and mathematics, researchers and engineers from academia and industry, as well as government employees.

Download or read book Advanced Routing Protocols for Satellite and Space Networks written by Chao Chen and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Satellite systems have the advantage of global coverage and offer a solution for providing broadband access to end users. Local terrestrial networks and terminals can be connected to the rest of the world over Low Earth Orbit (LEO) satellite networks simply by installing small satellite interfaces. With these properties, satellite systems play a crucial role in the global Internet to support real-time and non-real-time applications. Routing in satellite networks, and the integration of satellite networks and the terrestrial Internet are the key issues to support these services. Furthermore, the developments in space technologies enable the realization of deep-space missions such as Mars exploration. The Interplanetary Internet is envisioned to provide communication services for scientific data delivery and navigation services for the explorer spacecrafts and orbiters of future deep-space missions. The unique characteristics posed by deep-space communications call for different research approaches from those in terrestrial networks. The objective of this research is to develop advanced architectures and efficient routing protocols for satellite and space networks to support applications with different traffic types and heterogeneous quality-of-service (QoS) requirements. Specifically, a new QoS-based routing algorithm (QRA) is proposed as a connection-oriented routing scheme to support real-time multimedia applications in satellite networks. Next, the satellite grouping and routing protocol (SGRP) is presented as a unicast routing protocol in a two-layer satellite IP network architecture. The border gateway protocol - satellite version (BGP-S) is then proposed as a unified routing protocol to accomplish the integration of the terrestrial and satellite IP networks at the network layer. Finally, a new routing framework, called the space backbone routing (SBR), is introduced for routing through different autonomous regions in the Interplanetary Internet. SBR provides a self-contained and scalable solution to support different traffic types through the Interplanetary Internet.

Download or read book An Analysis of Dynamic Routing Protocols in Highly Distributed Data Networks written by Andrew Steven Kessler and published by . This book was released on 1993 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Service Efficient Network Interconnection Via Satellite written by Y. Fun Hu and published by John Wiley & Sons. This book was released on 2002-01-21 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provide access to such facilities in developing regions of the world is also viable and particularly attractive in the short to mid-term. Private LAN connection facilities could also be made available to the corporate user, offering the possibility to establish broadband internet access within a closed user group. Such a scenario could be of interest to the financial sector. By gathering the knowledge and experiences of well-known satellite systems experts from different parts of Europe this comprehensive volume provides detailed analysis on technical aspects for interconnecting local area network using satellite. Starting from traffic source modelling for different types of applications and services to different types of transmission techniques and networking functions for supporting such services, different case studies are presented to analyse the performance of such technologies. By providing an insight to current and future developments in satellite communications systems and by covering a broad.