Assessment of a Gateway Switching Algorithm for Q/V-Band Smart Diversity Systems in the Q/V-Lift Project (original) (raw)

Gateway Switching in Q/V Band Satellite Feeder Links

IEEE Communications Letters, 2000

A main challenge towards realizing the next generation Terabit/s broadband satellite communications (SatCom) is the limited spectrum available in the Ka band. An attractive solution is to move the feeder link to the higher Q/V band, where more spectrum is available. When utilizing the Q/V band, due to heavy rain attenuation, gateway diversity is considered a necessity to ensure the required feeder link availability. Although receive site diversity has been studied in the past for SatCom, there is much less maturity in terms of transmit diversity techniques. In this paper, a modified switch and stay combining scheme is proposed for a Q/V band feeder link, but its performance is also evaluated over an end-to-end satellite link. The proposed scheme is pragmatic and has close to optimal performance with notably lower complexity.

Smart gateway diversity techniques and transport-layer issues for future satellite networks

Next-generation satellite networks will build on smart gateway diversity (SGD) architectures based on the large capacity offered by high-frequency bands (Q, V, and W) in order to achieve very high system availability figures (greater than 99%). Despite the numerous studies about system design, little literature has explored the networking problems arising when switching traffic flows from one gateway, subject to feeder link outage, to an alternate one. In this regard, particularly promising multi-path strategies are represented by multi-path transmission control protocol (MP-TCP) and concurrent multipath transfer-stream control transmission protocol, which are the main aim of this paper along with the management of quality of service (QoS) requirements. This work shows the attractive advantages offered by MP-TCP in various operative SGD scenarios and also explores how multi-path strategies can be efficiently combined with QoS-based scheduling strategies.

Optimization of Q/V-band Smart Gateway Switching in the framework of Q/V-Lift Project

2019 IEEE Aerospace Conference, 2019

High-Throughput Satellite (HTS) systems are expected to reach the milestone of terabit/s capacity in few years through the exploitation of Extremely High Frequencies (EHF), in particular Q/V-bands and W-band, in the feeder link. In this respect, the H2020 QV-LIFT project, kicked-off in November 2016, aims at filling crucial gaps in the ground segment technology required by future Q/V-band HTS systems. One of the most challenging objectives of QV-LIFT team is develop and test a smart gateway management system (SGMS) operating in the Q/V-band. The SGMS will implement fade mitigation techniques able to counteract the detrimental propagation impairments across the feeder link. This paper reports the optimization and simulation activities that have been performed to design SMGS control logic, with a focus on the atmospheric channel predictor and switching decision algorithm. The channel is fully characterized by synthetic time series of rain attenuation generated by a Multisite Time-series Synthesizer (MTS).

Assessment of Practical Smart Gateway Diversity Based on Multisite Measurements in Q-/V-Band

2021

Next generations of high throughput satellite (HTS) systems operating a <inline-formula> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula>-/<inline-formula> <tex-math notation="LaTeX">$V$ </tex-math></inline-formula>-band network of gateways (GWs) for the feeder link need to apply some form of smart gateway diversity (SGD) to ensure they meet the demanding availability targets. However, most of the published research on SGD usually resorts to ideal assumptions that are not realistic for an operational system. To evaluate in more depth the performance of practical SGD, this article exploits for the first time multisite propagation measurements for a network of six measurement sites (GWs) at 40 GHz. Based on this, it studies the performance of SGD in terms of feeder availability and number of switches between GWs taking into account the climatic region, the switching processing delay, the clustering of GWs, ...

QoS Support in SGD-Based High Throughput Satellite Networks

This paper proposes a quality of service (QoS) management framework for high throughput satellite (HTS) systems using extremely high frequency (EHF) frequency bands, which can achieve high capacity provided that feeder link outage events caused by severe weather conditions can be properly counteracted. To this regard, smart gateway diversity architectures implementing advanced gateway handover procedures are certainly attractive, although they can only partly mitigate the negative effects of adverse weather conditions in terms of packet losses, delays, and jitters, which significantly degrade the performance of delay-sensitive and delay-insensitive traffic flows. To cope with these technical challenges, we propose an incremental rerouting scheme to control congestion events because of capacity reduction during the transient phase, consisting of offloading high-priority QoS traffic flows from the affected gateway towards gateways operating in more favorable conditions. Moreover, we apply inter-flow network coding at the gateways to protect delay-insensitive flows from packet losses occurring during feeder link outage. Finally, extra capacity is reserved at the gateways to handle the additional traffic resulting from gateway handover. The theoretical analysis (validated by simulation campaigns) allowed characterizing network coding performance and confirming the potentialities of our QoS management framework for HTS systems. Index Terms— QoS management, inter-flow network coding, terabit satellite systems, smart gateway diversity.

Channel Prediction and Network Coding for Smart Gateway Diversity in Terabit Satellite Networks

Globecom 2014, December 8-12, 2014, Austin, Texas, 2014

This paper explores the network design implications to be taken into account in Smart Gateway Diversity (SGD) satellite systems, where gateway outage events have to be counteracted by efficient handover procedures. In more detail, enabling high data-rate satellite systems in these conditions requires efficient coordination strategies between gateways, upstream routers and Network Control Centre (NCC) to precisely estimate the need of handover and to efficiently manage the satellite resources. To this regard, this paper adopts a simple channel estimation algorithm and applies network coding to cope with packet losses deriving from possible inaccuracies on the prediction of the handover time. The results obtained via simulation confirm the capabilities of network-coding-based approaches and pave the way for further studies in the area of network for SGD satellite systems.

Gateway Diversity for Q/V Feeder Links: Requirements, Characteristics, and Challenges

In this paper, we review the work of the gateway diversity schemes for Q/V band feeder links for a future HTS system. As each gateway will carry very high capacity, it is essential to ensure very high availabilities for the feeder links, typically greater than 99.9%. In order to do so, spatial diversity is required, since Adaptive Coding and Modulation (ACM) and Uplink Power Control (UPC) are unable to cope with the fade dynamics encountered at these high frequency bands. In an effort to reduce the total number of gateways in the system and to result in a more cost effective system, the concept of Smart gateways has emerged. We first review different architectures implementations and highlight their similarities and differences. We then outline the technological challenges and the issues that the envisaged solutions should consider during the design process. Finally we give views on a technology roadmap to meet these challenges.

Gateway Handover Implications on Transport Layer Performance in Terabit Satellite Networks

ASMS 2014, September 8-10, 2014, Livorno, Italy, 2014

Next-generation satellite systems are expected to provide an overall capacity of Tbit/s, whereby the use of higher frequency bands (e.g., Q, V, or W) will be required. In this regard, the satellite network will implement gateway (GW) diversity schemes and handover techniques to cope with the cases where GW feeder links experience outage due to weather-induced channel degradations. The efficient use of the available satellite capacity calls for multi-link transmission paradigms, which are currently not supported by TCP, but can be enabled by the more recent MP-TCP protocol that is based on a multi-homing approach. Hence, this paper explores the benefits achieved by adopting MP-TCP in a smart GW diversity scenario, showing that this technique allows a smooth support of GW handover events.

UNBALANCED LARGE SCALE MULTIPLE SITE DIVERSITY PERFORMANCE IN SATELLITE COMMUNICATION NETWORKS

2000

Frequency bands well above 10GHz are of primary importance for current and, more importantly, future user oriented satellite communication networks. In this course, well known rain fade mitigation techniques such as site diversity are reviewed and considered for use in a different context. This paper extends previous analytical methodologies to the case of large scale site diversity, that is, satellite