With the increasing number of user terminals (UTs), interference among UTs might significantly decrease throughput low earth orbit satellite communication system. In this paper, scheduling method is investigated to suppress interference. Specifically, leveraging strong spatial directivity channels, a low-complexity angle-based orthogonal selection (AOUS) algorithm proposed, which selects with n...

In Low Earth Orbit (LEO) mega constellations, there are relevant use cases, such as inference based on satellite imaging, in which a large number of satellites collaboratively train machine learning model without sharing their local datasets. To address this problem, we propose new set algorithms Federated (FL), including novel asynchronous FL procedure FedAvg that exhibits better robustness ag...

A novel LEO/MEO two-tier satellite communication system with inter-satellite links ( I S L r ) is proposed for providing multimedia services to global mobile users. This two-tier syxtem architecture can reduce the transmission delay for long-distunce users via ME0 satellites while keeping the benefits of using LEO satellites as the service access nodes. The routing and re-routing during a hando...

Abstract—Snapshot is a fundamental notion proposed for routing in mobile low earth orbit (LEO) satellite networks which is characterized with predictable topology dynamics. Its distribution has a great impact on the routing performance and on-board storage. Originally, the snapshot distribution is invariable by using the static snapshot partition method based on the mechanical steering antenna....

A GPS Radio Occultation occurs when a transmitting GPS satellite, setting or rising behind the Earth limb, is viewed by a LEO satellite that carries on board a space-qualified GPS receiver. In this way, it is provided a vertical sounding of the atmosphere exploiting the relative motion between the GPS and the LEO satellites. The technique proved to be particularly precise in retrieving temperat...

In this document we describe the architecture of BRAHMS (Broadband Access for High speed Multimedia via Satellite), project sponsored by EU in the framework of IST research programme. BRAHMS aims at specifying an IP-based architecture for broadband satellite access independently of the particular GEO or LEO satellite technology adopted in the satellite link. Broadband Multimedia Satellite Syste...

Sequential satellite microwave images of tropical cyclones readily lend themselves to morphing applications, which allow for a straightforward visualization of the storms' structural trends. P olar and other low-Earth-orbiting (LEO) satellites provide critical data for use in weather analysis and forecasting. However, the temporal sampling issue leads to the common problem of interpreting seque...

A number of satellite communication systems have been proposed using geosynchronous (GEO) satellites, as well as low earth orbit (LEO) constellations operating in the Ka-band and above. At these frequencies satellite networks are able to provide broadband services requiring wider bandwidth than the current services at C or Ku-band. As a consequence, some of the new services gaining momentum inc...