Optical feeder link architectures for very HTS: ground segment

Abstract

The paper deals with an analysis of Very High Throughput Satellite (VHTS) systems employing optical feeder links. As the capacities of newly announced next generation VHTS systems are exceeding the Terabit/s barrier, a large amount of investment needs to be directed not only to the space segment (as was the case traditionally), but also to the ground segment in support of the feeder links. To reduce this investment, satellite operators are reviewing various options and technologies for the feeder links, among which optical feeder links [1]. In this paper, different approaches are analysed for ground segment networks relying on Optical Ground Stations (OGS), exploring the concept of smart gateway diversity with N active OGS and P redundant ones, like is currently done in VHTS systems with RF feeder links. OGS locations are assessed in terms of aggregate availability and total cost for the satellite operator, which is an essential element for the viability of the VHTS system. Different options are assessed for the distribution of OGS gateway processing functions (local at OGS or centralised), and for their interconnection. The main technical challenges are discussed, identifying which technologies will be required for an operational VHTS system with OGS.

Free-space optical communication technologies will enable next generation of ultra high throughput satellite

“…The number and location of optical feeder stations are no longer constrained by considerations on frequency re-use or regulation issues but only on climatic conditions. Several studies have shown that a dozen stations in Europe (preferably in the south) can feed a VHTS in the 500-Gbps class with the required availability [2], [3]. As the satellite is accessed by a single station, all the traffic must be routed to the active station and the diversity network must be sized accordingly and consequently will be more expensive.…”

Joint Satellite Gateway Deployment & Controller Placement in Software-Defined 5G-Satellite Integrated Networks

“…Several papers have studied gateway diversity towards the optimization of High-Throughput Satellite (HTS) architectures. These works typically aim at optimizing the smart gateway configuration [33], gateway assignment [32], paving the way towards optical feeder links and dealing with atmospheric turbulence [34].…”

“…With such an approach, the authors in [23] have previously used the algorithm mentioned in theorem 3, for SDN controller placement at edge. In a similar fashion, let Vg be the maximum of equation (34). Thus, minimizing (34) is tantamount to maximizing…”

Optical feeder link architectures for very HTS: issues and possibilities

“…Several studies have addressed this problem and have calculated the required number of OGSs for achieving a very high availability, either based on pure probability analysis or based on actual cloud coverage databases. A companion paper in the ICSO 2018 [5] is presenting a relevant analysis using a comprehensive generative tool developed under ESA INFRA "Optical/RF Tool," contract [6].…”

“…The paper highlights a number of technical issues that arise when adopting a particular optical feeder link architecture, and proposes key areas of R&D that need to be considered by the optical communications community. It does not address the topic of cloud blockage and on-ground spatial diversity (dealt with in a companion paper [5]), assuming that the number of optical ground stations is sufficient to guarantee the target feeder link availability.…”