On Channel Sharing Policies in LEO Mobile Satellite Systems

We consider a low earth orbit (LEO) mobile satellite system with "satellite-fixed" cells that accommodates new and handover calls of different service-classes. We provide an analytical framework for the efficient calculation of call blocking and handover failure probabilities under two channel sharing policies, namely the fixed channel reservation and the threshold call admission policies. Simulation results verify the accuracy of the proposed formulas. Furthermore, we discuss the applicability of the policies in software-defined LEO satellites

QoS based Admission Control using Multipath Scheduler for IP over Satellite Networks

This paper presents a novel scheduling algorithm to support quality of service (QoS) for multiservice applications over integrated satellite and terrestrial networks using admission control system with multipath selection capabilities. The algorithm exploits the multipath routing paradigm over LEO and GEO satellites constellation in order to achieve optimum end-to-end QoS of the client-server Internet architecture for HTTP web service, file transfer, video streaming and VoIP applications. The proposed multipath scheduler over the satellite networks advocates load balancing technique based on optimum time-bandwidth in order to accommodate the burst of application traffics. The method tries to balance the bandwidth load and queue length on each link over satellite in order to fulfil the optimum QoS level for each traffic type. Each connection of a traffic type will be routed over a link with the least bandwidth load and queue length at current time in order to avoid congestion state. The multipath routing scheduling decision is based on per connection granularity so that packet reordering at the receiver side could be avoided. The performance evaluation of IP over satellites has been carried out using multiple connections, different file sizes and bit-error-rate (BER) variations to measure the packet delay, loss ratio and throughput

Handover Management In Mobile Satellite Communications

Mobile satellite communication offers vast coverage area with moderate bandwidth demands. However, in mobile satellite communication using Low Earth Orbits (LEO) satellite service, handover frequently occurs due to high velocity and large number of mobile satellites. With increase demand of multimedia traffic, an optimum utilization of network resources has been investigated. To accommodate and maintain Quality of Service (QoS) of handover calls in mobile satellite communication, priority for handover calls are applied. Traffic parameters of traffic arrival rate, traffic duration and priority among traffic applications are introduced. Traffic applications of type voice, video and data are observed and analysis of traffic behavior on handover has been done. An optimum set of channels to serve the different traffic types is proposed after considering the handover initiation and handover execution criteria. The algorithm proposes a more accurate measurement of handover initiation angle, introduced as look-up angle, which further reduces handover rate and successfully conserve the network resources

Application of advanced on-board processing concepts to future satellite communications systems: Bibliography

Abstracts are presented of a literature survey of reports concerning the application of signal processing concepts. Approximately 300 references are included

System level performance of ATM transmission over a DS-CDMA satellite link.

PhDAbstract not availableEuropean Space Agenc

Gateway placement optimization in LEO satellite networks based on traffic estimation

​© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Adopting satellite constellations to provide global Internet access services has recently drawn increasing attention. A Low Earth Orbit (LEO) satellite network with multiple satellites has global coverage ability, low latency and independent operation, so it can be an effective complement to terrestrial IP networks. Satellite gateways are placed on the ground and can serve as data exchange points between satellite networks and the Internet. As the placement scheme can affect the network performance, it is a fundamental problem to find appropriate sites for gateways. In this paper, a Gateway Placement Optimization (GPO) method in LEO satellite networks is proposed to solve the problem, which is modeled as a combination optimization problem. Our aim is to select the best places for gateways that can balance the traffic loads with as few gateways as possible. The constraints come from the physical links between gateways and satellites including the link interference, the satellite bandwidth and the number of satellite antennas. The gravity model is used to estimate the traffic matrix from/to gateways and satellites, and then the discrete Particle Swarm Optimization (PSO) algorithm is adopted and modified to solve this problem. Finally, the GPO method is applied to numerical tests involving real satellite constellation networks. Results indicate that our method has good performance and effectiveness.Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura::9.1 - Desenvolupar infraestructures fiables, sostenibles, resilients i de qualitat, incloent infraestructures regionals i transfrontereres, per tal de donar suport al desenvolupament econòmic i al benestar humà, amb especial atenció a l’accés assequible i equitatiu per a totes les personesObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura::9.c - Augmentar de forma significativa l’accés a les tecnologies de la informació i la comunicació i esforçar-se a proporcionar accés universal i assequible a Internet als països menys avançats a tot tardar el 2020Postprint (author's final draft

Scheduling flows over LEO constellations on LMS channels

Satellite systems typically use physical and link layer reliability schemes to compensate the significant channel impairments, especially for the link between a satellite and a mobile end-user. These schemes have been introduced at the price of an increase in the end-to-end delay, high jitter or out-of-order packets. This is show to have a negative impact both on multimedia and best-effort traffic, decreasing the Quality of Experience (QoE) of users. In this paper, we propose to solve this issue by scheduling data transmission as a function of the channel condition. We first investigate existing scheduling mechanisms and analyze their performance for two kinds of traffic: VoIP and best-effort. In the case of VoIP traffic, the objective is to lower both latency and jitter, which are the most important metrics to achieve a consistent VoIP service. We select the best candidate among several schedulers and propose a novel algorithm specifically designed to carry VoIP over LEO constellations. We then investigate the performance of the scheduling policies on Internet-browsing traffic carried by TCP, where the goal is now the maximize the users’ goodput, and select the best candidate in this case