Democratizing LEO Satellite Network Measurement

Low Earth Orbit (LEO) satellite networks are quickly gaining traction with promises of impressively low latency, high bandwidth, and global reach. However, the research community knows relatively little about their operation and performance in practice. The obscurity is largely due to the high barrier of entry for measuring LEO networks, which requires deploying specialized hardware or recruiting large numbers of satellite Internet customers. In this paper, we introduce HitchHiking, a methodology that democratizes global visibility into LEO satellite networks. HitchHiking builds on the observation that Internet-exposed services that use LEO Internet can reveal satellite network architecture and performance, bypassing the need for specialized hardware. We evaluate HitchHiking against ground truth measurements and prior methods, showing that it provides more coverage and accuracy. With HitchHiking, we complete the largest study to date of Starlink network latency, measuring over 2,400 users across 13 countries. We uncover unexpected patterns in latency that surface how LEO routing is more complex than previously understood. Finally, we conclude with recommendations for future research on LEO networks.Comment: Pre-Prin

Survivability Analysis of the Iridium Low Earth Orbit Satellite Network

This thesis evaluates the survivability of the proposed Iridium Low Earth Orbit (LEO) Satellite Network. In addition to the complete Iridium constellation, three degraded Iridium constellations are analyzed. This analysis occurs via the use of simulation models, which are developed to use three dynamic routing algorithms over three loading levels. The Iridium network models use a common set of operating assumptions and system environments. The constellation survivability was determined by comparing packet rejection rates, hop\u27 counts, and average end to end delay performance between the various network scenarios. It was concluded that, based on the established scenarios, the proposed Iridium constellation was highly survivable. Even with only 45 percent of its satellites functioning (modeled with 36 failed Iridium satellites), the average packet delays were never greater than 178 milliseconds (msec), well within the real time packet delivery constraint of 400 msec. As a result, while additional research is necessary, Iridium has demonstrated the network robustness that is required within the military communications environment

Performance Analysis of Protocol Independent Multicasting-Dense Mode in Low Earth Orbit Satellite Networks

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® 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

Explicit Load Balancing Technique for NGEO Satellite IP Networks With On-Board Processing Capabilities

科研費報告書収録論文(課題番号:17500030/研究代表者:加藤寧/インターネットと高親和性を有する次世代低軌道衛星ネットワークに関する基盤研究

Logical topology-based routing in LEO constellations

Satellite communication is distinguished by global coverage and the ability to support a wide range of applications. LEO (Low Earth Orbit) satellite systems employing inter-satellite links offer rich connectivity in space and provide direct broadband access and personal communication service. One of the technical challenges for LEO systems is the design of efficient routing strategies tailored to their highly dynamic nature. In this paper, we present a new routing method which solves the routing problem effciently by overlaying a static logical topology over the physical constellation. The algorithm generates near-optimal shortest paths. The performance of our proposed scheme is evaluated through theoretical analysis and simulations.published_or_final_versio

Geographical and Orbital Information Based Mobility Management to Overcome Last-Hop Ambiguity over IP/LEO Satellite Networks

科研費報告書収録論文(課題番号:17500030/研究代表者:加藤寧/インターネットと高親和性を有する次世代低軌道衛星ネットワークに関する基盤研究

ERSVC: An Efficient Routing Scheme for Satellite Constellation Adapting Vector Composition

AbstractCompared with GEO and MEO satellites, LEO satellite constellation is able to provide low-latency, broadband communications which is difficult to be provided by the GEO or MEO satellites. However, one of the challenges in LEO constellation is the development of an efficient and specialized routing scheme. This paper takes transmission rate and data transmission time into consideration, and proposes ERSVC, an efficient routing scheme for satellite constellation adapting vector composition. ERSVC reduces routing table computation complexity, and saves restricted satellite resources. By adapting vector composition method, the amount of data flowing into satellite constellation is maximized while the data traffic is well controlled. Correlative and comprehensive simulation indicates that ERSVC is superior to existing schemes for LEO satellite constellation, especially in balancing data flow