Multicast-aware power allocation in multiple spot-beam satellite communication systems

SUMMARYSatellite systems and high-altitude platform systems working in Ka and V bands require the application of adaptive techniques in order to mitigate link degradations caused by atmospheric impairments such as those due to cloud cover. Among these techniques, resource sharing system techniques and site diversity need information on the spatial distribution of impairments caused by cloud cover, including the probability of simultaneous occurrence of adverse conditions in various regions.A study has been performed in Spain, within the framework of COST Action 280, to investigate the large-scale spatial distribution of cloud cover using synoptic meteorological data. Cloud cover distribution for individual sites and the spatial correlation properties for pairs of sites have been investigated. The geographical distributions of the values obtained from the statistical analysis have been represented in maps of contour lines using standard mapping procedures. Correlation parameters are expected to decrease with distance; however, the maps derived taking a given site as reference reveal a significant influence of climatic and geographic factors such as weather fronts, orography or the proximity to the sea. The statistics and maps obtained can be useful to optimize power sharing in multi-beam satellite systems, as suggested in this paper.

Section: Discussion: Suggested Applicationsmentioning

confidence: 99%

Spatial distribution of cloud cover

García¹,

Benarroch²,

Riera³

2008

“…From the four resources introduced above, recent research has focused on power allocation, 4–8 while the other satellite resources such as the frequency assignment and beam placement have been less studied. The latter two problems have been shown to be NP hard, 9,10 which is why brute force algorithms are unfeasible for medium‐ to large‐scale scenarios (ie,

>

850 beams, as we show later).…”

Section: Introductionmentioning

confidence: 99%

Static beam placement and frequency plan algorithms for LEO constellations

Osa

Guerster

Barrios

et al. 2020

LEO satellites are growing rapidly in number, but also in configurability of the payload, which presents new challenges of how to allocate the satellite's resources. We present an algorithm to solve two subproblems of the resource allocation problem for multi-beam satellites in large LEO constellations. Our approach produces a static beam placement and a static frequency plan, taking into account the user demands and interference conditions, respectively. We provide an easy to implement and fast approximation for the beam placement problem, which is converted into an Edge Clique Cover problem using graph theory. The frequency assignment problem is translated into a constraint satisfaction problem, which is later solved with a first-fit heuristic. We apply our algorithm to a scenario based on SpaceX's Starlink constellation, and when compared to two different baselines, we show that our method requires 40% fewer beams while being able to provide service to 2% more users.

“…It is envisaged in [2] that future large-capacity satellites, using both Ka and Q/V bands, will combine such technologies with site diversity applied to networks of Gateway Earth Stations. Multibeam systems make use of shared on-board resources, so that the available power can be allocated among the beams taking into account both traffic requirements and channel conditions [3,4]. Therefore, the probability that a given number of spot beams are affected simultaneously by bad weather conditions that may cause impairments in the corresponding links needs to be investigated.…”

Section: Introductionmentioning

confidence: 99%

Large‐scale correlation of rainfall rate based on data from Spanish sites

Garcia‐del‐Pino

Benarroch

Riera

2014

SUMMARY Modern and future satellite systems working in the Ka and Q/V bands often require the application of site diversity to mitigate the degradations caused by rain. Satellite systems operating in these bands may make use of multi‐beam techniques to provide high‐capacity services. To achieve an efficient performance in both techniques, precise information is necessary on the occurrence of simultaneous rain fades in various links under a given satellite coverage. This is attained through the knowledge of the spatial characteristics of rainfall rate over the area of interest. The availability of a large database of rain gauge data from about 50 sites in Spain has allowed the undertaking of a study on the large‐scale spatial distribution of rainfall rate. Joint distributions and correlation parameters have been investigated for pairs of sites, and experimental results have been compared with predictions based on the ITU‐R site diversity model, obtaining the best results when stratiform rainfall is dominant in both sites. Some statistical dependence has been found even for distances above 700 km. The values obtained from the statistical analysis have been represented taking a given site as reference in maps of contour lines using standard mapping procedures. Correlation parameters are expected to decrease with distance; however, the contour maps reveal a significant influence of climatic and geographic factors such as weather fronts, orography or the proximity to the sea. The statistics and maps obtained are useful to optimise both power sharing in multi‐beam satellite systems and the application of site diversity. Copyright © 2014 John Wiley & Sons, Ltd.