QV-LIFT Project: Using the Q/V Band Aldo Paraboni Demonstration Payload for Validating Future Satellite Systems

Abstract

In future communication satellite systems the adoption of higher frequencies as Q/V-band (around 40 GHz for downlink and 50 GHz for uplink) is seen as the promising step forward to achieve higher performance in terms of total system throughput. The envisaged usage of these frequency bands, bringing an additional 5 GHz bandwidth in each polarization (10 GHz in total), is dual: as feeder link for Fixed Satellite Service (FSS) systems and as user link for Mobile Satellite Service (MSS) for aeronautical terminals.
The QV-LIFT project is paving the road for the future deployment of such Q/V-band SatCom systems, providing core technologies for both ground and user segments. The subsystems developed in the course of the project will be tested in a real environment using the Q/V-band Aldo Paraboni payload on Alphasat and its associated ground segment, made available by the Italian Space Agency (ASI).
This project has been granted by the European Commission and involves a consortium of companies and universities coordinated by the Italian Space Agency (Agenzia Spaziale Italiana, ASI). The consortium consists of: Consorzio Nazionale Interuniversitario per le Telecomunicazioni (CNIT), Martel GmbH (Martel), Erzia Technologies SL (Erzia), Eutelsat S.A. (Eutelsat), M.B.I. SRL (MBI), Heriot-Watt University (HWU), SkyTech Italia SRL (SkyTech), OMMIC SAS (OMMIC).
This paper presents part of the project activities, such as the description of one possible future Very High Throughput Satellite (VHTS) scenarios for Q/V-band systems. Furthermore, the technologies currently under development and the system test architecture which will be used to validate the developed technology and functionalities are presented.

Full text

QV-LIFT Project: Using the Q/V Band Aldo Paraboni Demonstration
Payload for Validating Future Satellite Systems
F. Massaro, M. Bergmann, R. Campo, M. Thiebaut, D. V. Finocchiaro, A. Arcidiacono
fmassaro@eutelsat.com, mbergmann@eutelsat.com, rcampo@eutelsat.com,
mthiebaut@eutelsat.com, dfinocchiaro@eutelsat.com, aarcidiacono@eutelsat.com,
Eutelsat SA (FRA)
G. Goussetis, J. A. Garcia-Perez
g.goussetis@hw.ac.uk, jag34@hw.ac.uk,
Heriot Watt university (UK)
G. Amendola,
g.amendola@dimes.unical.it,
CNIT-Università della Calabria (ITA)
C. Riva,
carlo.riva@polimi.it,
Politecnico di Milano (ITA)
R. Nebuloni,
roberto.nebuloni@ieiit.cnr.it,
IEIIT- Consiglio Nazionale delle Ricerche (ITA)
G. Bacci,
gbacci@mbigroup.it,
MBI (ITA)
M. Sigler
manuel.sigler@erzia.com,
ERZIA Technologies (SPA),
F. Cipolloni, R. Eleuteri
fcipolloni@skytechitalia.it, releuteri@skytechitalia.it,
SkyTech Srl (ITA)
G. Codispoti, G. Parca
giuseppe.codispoti@asi.it, giorgia.parca@asi.it,
ASI – Agenzia Spaziale Italiana (ITA)
Abstract
In future communication satellite systems the adoption of higher frequencies as Q/V-band (around 40
GHz for downlink and 50 GHz for uplink) is seen as the promising step forward to achieve higher
performance in terms of total system throughput. The envisaged usage of these frequency bands,
bringing an additional 5 GHz bandwidth in each polarization (10 GHz in total), is dual: as feeder link for
Fixed Satellite Service (FSS) systems and as user link for Mobile Satellite Service (MSS) for
aeronautical terminals.
The QV-LIFT project is paving the road for the future deployment of such Q/V-band SatCom systems,
providing core technologies for both ground and user segments. The subsystems developed in the
course of the project will be tested in a real environment using the Q/V-band Aldo Paraboni payload
on Alphasat and its associated ground segment, made available by the Italian Space Agency (ASI).
This project has been granted by the European Commission and involves a consortium of companies
and universities coordinated by the Italian Space Agency (Agenzia Spaziale Italiana, ASI). The
consortium consists of: Consorzio Nazionale Interuniversitario per le Telecomunicazioni (CNIT), Martel
GmbH (Martel), Erzia Technologies SL (Erzia), Eutelsat S.A. (Eutelsat), M.B.I. SRL (MBI), Heriot-Watt
University (HWU), SkyTech Italia SRL (SkyTech), OMMIC SAS (OMMIC).
This paper presents part of the project activities, such as the description of one possible future Very
High Throughput Satellite (VHTS) scenarios for Q/V-band systems. Furthermore, the technologies
currently under development and the system test architecture which will be used to validate the
developed technology and functionalities are presented.
Introduction
1.
Future VHTS systems must be capable to cope with the growing demands at competitive prices. In
order to provide the necessary capacity of 400 Gbps or more for future VHTS an evolution to Q/V-

band (40/50 GHz) for feeder links will be necessary. The high interest for this frequency band is
confirmed by the demand for bandwidth that has been shown by well-known satellite manufacturers,
such as Boeing, which proposed big LEO constellation with downlink in the 37.5 – 42.5 GHz and
uplink in 47.2 to 50.2 and 50.4 to 52.4 GHz band. The related filing was delivered to FCC and ITU in
November 2016. Boeing’s request was followed recently by other proposals for potential use of V-
band satellites by other companies such as SpaceX, Telesat and Theia (see [1] and [2]).
Signal fading in Q/V-band can exceed 30 dB as indicated in Figure 1, showing the Complementary
Cumulative Distribution Function (CCDF) of atmospheric attenuation at 37 GHz for six sites in Europe.
Fade mitigation techniques, such as the adaptive power control (APC) and the adaptive coding and
modulations (ACM), do not provide a sufficient dynamic range by themselves.
Figure 1: 37 GHz CCDF of atmospheric attenuation along six Earth-to-GEO satellite paths
To overcome that, strategies have been proposed in literature. Promising ones for future VHTS
systems were published as smart gateway and soft diversity [3] and [4].
The QV-LIFT
1
project investigates on the applicability of such techniques and provides technological
solutions with high level of technology readiness so as to foster the competitiveness of European
industry as key technology providers for Q/V-band.
The rest of the paper is organized as follows: Section 2 provides a generic example of a future VHTS
system for Mobile Satellite Services (MSS). In Section 3 the concepts of smart gateway and soft
diversity are presented, followed by a brief description in Section 4 of the technology under
development in the QV-LIFT project. Section 5 discusses the envisaged test set-up used for validating
the technology development and the innovative functionalities. Finally, conclusions are drawn in
Section 6.
Future VHTS systems
2.
In QV-LIFT, Eutelsat has devised a MSS sample scenario which focuses on the provision of data
services for airborne users. Despite trying to be a reasonably realistic reference for the technological
developments in QV-LIFT, the values for the space and ground segments herein provided do not
represent a commercial commitment for Eutelsat, but are meant for research purposes only.
Generally, airborne links are not heavily impaired by the troposphere because the satellite link will
mainly be used at cruising altitude. Resorting to Q/V-band thus provides higher antenna gains at the
same form factor compared to lower frequencies. Future MSS scenarios are considered to provide
data and entertainment for users including telemetry (MSS-TM). In the context of QV-LIFT, the
following assumptions have been made:
• The user and feeder links in mobile satellite services shall be provided in Q/V-band.
1
https://www.qvlift.eu/

• The system shall be capable to provide mobile broadband internet services and telemetry
for airborne users at cruising altitude.
The MSS case focusses primarily on the airborne Q/V user link, inherently assuming the presence of
adequate feeder links.
Figure 2: Assumed MSS scenario
The computed link budget refers to the envisaged system performances:
Envisaged user link performance figures (Q/V-band)
• Satellite G/T toward user = 19.0 dB/K (edge of coverage - EOC)
• Satellite EIRP toward user = 33.2 dBW/MHz
• Satellite aggregated interference between users = 21 dB
• Satellite linearity toward user = 18 dB
Envisaged gateway performances figures (Q/V-band)
• Satellite G/T toward GW = 25.0 dB/K
• Satellite EIRP toward GW = 29.0 dBW/MHz
• Satellite aggregated interference between GWs = 23 dB
• Satellite linearity toward GW site = 21 dB
The computed link budget for MSS scenario takes into account the fact that the user terminal is
mounted on the aircraft and operated at cruising altitude. Hence tropospheric effects reduce to a
minimum. Remaining gas absorptions are considered, which amount to a maximum of 0.1 dB in
accordance with the measurements performed by CNIT-Politecnico di Milano [8].
Moreover, a G/T for the airborne terminal of 15.7 dB/K is envisaged according to calculations in Table
1 based on a 0.45m parabolic reflector antenna. It can be observed that the terminal receiver noise
temperature corresponds to a noise figure of 2.5 dB. This value is considered challenging with the
technology currently available: to mitigate development risks, a noise figure of 3 dB (see Table 5) has
been taken into account.
The link budget in Table 2 shows that on the forward link a data rate of 179 Mbps and on the return
link a data rate of 49 Mbps can be achieved, which corresponds approximately to a reasonable 4:1
forward to return ratio between the two links.

Table 1: Airborne terminal specifications for future MSS scenarios
Table 2: Clear Sky Link Budget – MSS IFEC forward and return links
Antenna Diameter 0.45 m
Efficiency 0.70
Frequency (MHz) 40000.00 MHz
Antenna Gain = η.(π.D/λ)² 44.0 dBi
Radome Losses 1.0 dB
Loss + Mismatch 1.5 dB
Antenna Noise Temperature 94 K
Repeater Noise Temperature 226 K
System Noise Temperature 25.8 dBK
Gain over Noise Temperature 15.7 dB/K
Configurations:
Forward Link Return L ink
Frequency (MHz) 47200.00 MHz 50900.00 MHz
Symbol-Ra te 227.27 Msymb/s 28.00 Ms ymb/s
MODCOD QPSK 2/5 8-PSK 7/1 2
Spectral Efficienc y 0.79 bi ts/symb 1.75 bi ts/symb
0.72 bps /Hz 1.40 bps /Hz
Required Es /No 0.40 dB 7.70 dB
Target Throughput 179.41 Mbit/s 49.00 Mbit/s
Roll -off factor 10.00% 25 .00%
Bandwi dth (MHz) 250.00MHz 35.00 MHz
Uplink EIRP toward satellite 74.1 dBW 55.0 dBW
Upli nk EIRP Densi ty 50.1 dBW/ MHz 39.6 dBW/MHz
IPFD a t satelli te -92.5 dBW/m ² -107.8 dBW/m²
Upli nk Free-Space Loss = 4πD/λ 217.6 dB 218.2 dB
Atmospheric attenuati on 3.9 dB 0.1 dB
Satellite G/T towards Transmit GS 25.0 dB/K 19.0 dB/K
IPFD - G/T -117.5 dBW/m² -126.8 dB W/m²
Upli nk C/N = EIRP - L + G/T - k. - B 22.6 dB 9.8 dB
Upli nk C/Im
30.0 dB
16.0 dB
Upli nk C/I
23.0 dB
21.0 dB
Uplink C/(N+I)
19.4 dB
8.6 dB
Upli nk C/No 106.2 dBHz 84.3 dBHz
Downli nk Range
3828 5 km
3828 5 km
Downli nk Frequency 40000.00 MHz 38000.00 MHz
Receive GS G/T towards Satellite 15.7 dB/K 42.0 dB/K
Downlink EIRP towards GS 60.2 dBW 48.9 dBW
OBO 3.0 dB 4.5 dB
EIRP densi ty 33.2 dBW/MHz 29.0 dBW/MHz
Downli nk Free-Space Loss 216.1 dB 215.7 dB
Atmospheric attenuati on 0.1 dB 4.0 dB
Provi sion (p ointing, l osses, etc) 0.7 dB 0.0 dB
IPFD a t Downli nk GS -105.6 dBW/m ² -122 .2 dBW/m²
Downli nk C/N 1.0 dB 20.9 dB
Downli nk C/Im
18.0 dB
20.0 dB
Downli nk C/J
21.0 dB
23.0 dB
Downlink C/(N+I)
0.8 dB
16.3 dB
Downli nk C/No 84.5 dBHz 95 .3 dBHz
Overall C/(N+I) 0.78 dB 7.93 dB
Overall C/(No+I) 84.5 dBHz 83.9 dBHz
Overall Margin 0.38 dB 0.23 dB
TX Ground Station
RX Groun d St ation
UPLINK
OVERALL LINK
HTS MSS IFEC
QV for both Users and
Feeders
DOWNLINK

Smart Gateway and Soft Diversity
3.
A VHTS system must ensure the agreed service levels to the users thus requiring mitigation strategies
to compensate for deep fading events in Q/V-band.
Beyond techniques like adaptive coding and modulation (ACM) and dynamic power control, GW
diversity strategies as briefly discussed in the following need to be taken into account.
In the simplest satellite architecture scenario, each gateway serves a fixed number of beams.
Redundancy is applied by providing a spare GW for each active GW (single site diversity) [6]. Without
further discussion this technique may be regarded as rather costly. Moreover, this strategy exposes all
users in one beam to the service interruption in case the related gateway is affected by strong
atmospheric fading.
Gateway diversity techniques can be employed tackling the detrimental effects of deep fading and
providing redundancy in case of gateway failure or maintenance.
A further concept uses a pool of N interconnected gateways that serve the same user beam and can
exchange the user traffic in order to limit service outages in case of deep fading. This technique is
denoted as smart gateway architecture [6][9]. Two solutions, denoted in the open literature as “N+0”
and “N+P” are further studied and tested in the course of the QV-LIFT project [5]. The naming
convention reflects the use of a network of N gateways without (“+0”) or with P (“+P”) additional
stations for redundancy.
N+0 architecture
N connected gateways provide the minimum number of gateways necessary to appropriately serve all
user beams.
The concept is supposed to provide advantages when outages occur [7].
By providing several carriers per beam it is easy to understand that in case of GW outage only a
fraction of the beam capacity is lost compared to a scenario where a beam is served by a single GW.
Nevertheless, in order to exploit this advantage user terminals either need to be capable to switch
between carriers or transmit and receive via more than one carrier simultaneously. Traffic routing
capabilities must be established appropriately [10].
In Figure 3 the smart gateway architecture is sketched. It may be noticed that every single carrier
generated by 

is transmitted along with the carriers from the other gateways within the same
beam. For simplicity, only four gateways and four beams are here depicted.
Figure 3: Smart gateway architecture

Envisioning a more flexible and dynamic scenario, the size of the carrier in each beam may be varied
according to the user needs or in case of gateway failures. This agility requires the presence of an
appropriate network management system (NMS), on top of a very flexible satellite payload. An
example setup is presented in Figure 4 considering all GWs managed by a central NMS. For sake of
completeness, a clustering of GWs may be considered for practical systems [7][9], but such
considerations remain out of scope for the presented activity.
Figure 4: NMS and gateways network
N+P architecture
The reduction in system capacity in case of GW outages can be mitigated if the ground segment is
capable of forecasting deep fades with enough lead time and precision. It than can issue appropriate
countermeasures including GW switching and migrating traffic to different carriers and so forth.
P additional gateways are considered here as replacements for GWs in outage. Ideally, the switching
and rerouting should be implemented such that the user does not notice any service interruption or
significant degradation. From an operational point of view, it may be convenient to keep nominal and
redundant stations active. Hence, a distributed back-up strategy could be envisaged for the N+P
approach. The gateways are operated at partial load. In case one GW goes in outage as sketched in
Figure 5, its carriers are hosted by utilizing free resources on other GWs [9]. Figure 5 (a) shows an
example of N+P architecture where all gateways, including the spare ones, are full time active and
operational, but not at their full load capabilities. In this way, as depicted in Figure 5 (b), in case of one
gateway failure, its carriers would be assigned to other available gateways.
Figure 5: full active gateways and distributed back-up architecture – (a) All gateways run at partial load,
(b) when GW1 goes in outage its resources are allocated to the available gateways.

Soft diversity
As complementary strategy to the smart gateway technology, soft diversity can be applied. It requires
the terminal to extract the traffic from different carriers transmitted to the beam. With this service
interruption can be reduced when switching carrier of a GW in outage. Nevertheless, the user terminal
must be capable to lock on more than one carrier simultaneously [11].
Key Technology Development in QV-LIFT
4.
During the QV-LIFT project, some key elements of a reference Q/V-band SatCom system are being
designed and developed:
• A Smart Gateway Management System (QV-SGMS) capable to predict in time the
propagation impairments on the feeder link and able to counteract them with soft diversity
techniques.
• An Earth Station (QV-ES) in Q/V-band with Block Up Converters (BUC) based on power
combined GaN MMICs.
• An Airborne Terminal (QV-AT) in Q/V-band with the same RF technology as in QV-ES.
Nomadic station (QV-ES)
This is a nomadic station equipped with a 1.5 m reflector antenna, LNB and BUC operating in Q/V-
band that are also under development. The station targets at offering a portable solution for easy and
quick deployment during the tests, and is being developed by the CNIT-Università della Calabria
(antenna and RF payload) and SkyTech (antenna positioner) (see [12]).
Block Up-Converter
Developed by Erzia, the BUC will satisfy the specifications in Table 3. The adopted technology is a
GaN based power amplifier MMIC to be used in a power combining scheme to achieve high level of
power. The MMIC design will implement itself a power combining architecture even if with a reduced
number of transistor so as to reduce complexity and size of the MMIC and improve efficiency by
reducing combining losses.
Parameter
Value
Input frequency
1.5 GHz
Bandwidth
500 MHz
Output frequency
47.2 – 50.2 GHz
Output
power
15 W (41.7 dBm)
Gain
40 - 60 dB
S11, S22
-10 dB
Interfaces
In: Coax, Out: WR-
19
Table 3: BUC preliminary specifications
Low Noise Block converter
Developed by Erzia, the LNB will satisfy the preliminary specifications in Table 4 and reutilize the
same technology process adopted for the fabrication of the BUC.
Parameter
Value
Input frequency
37.5 – 42.5 GHz
Bandwidth
500 MHz
Output
frequency
1.25 – 1.75 GHz
Input power
-130 dBm

Noise Figure
<3.5 dB
Gain
>50 dB
S11, S22
-10 dB
Interfaces
In: WR-22, Out:
Coax
Table 4: LNB preliminary specifications
Airborne Terminal (QV-AT)
During the project, a complete, functioning (TRL-6) Airborne Terminal (QV-AT) will be developed,
providing a two-way On-The-Move communication link for aircrafts and exploiting Q/V-band via the
geostationary satellite Alphasat. SkyTech, responsible for electromechanical design of the pedestal,
will integrate the BUC and LNB from ERZIA, and the RF payload from CNIT. The design will consider
that such devices can be tail-mounted or fuselage-mounted.
Interactive Satellite Terminal (IST)
Eutelsat will provide an adapted version of the SmartLNB terminal, which is the current
implementation of the interactive satellite terminal (IST), operational and commercially deployed for
machine-to-machine applications, IoT backhauling and other narrowband applications. This IST is a
device originally designed to provide a bidirectional narrowband channel on top of reception of normal
TV channels in Ku-band. It gives the functionalities of an IP satellite modem, with a return link channel
optimized for short transmissions of IP packets. The return link can be in Ka or Ku-band, depending on
the model. For the QV-LIFT project a version of the IST modem providing the signals on the
intermediate L-band interface will be developed, as in Figure 6, so as to guarantee compatibility with
the developed QV-ES and QV-AT.
Figure 6: IST Modem with L-band interfaces
The IST uses the F-SIM waveform [13][14][16]. The F-SIM physical layer is based on a spread
spectrum waveform and an ALOHA protocol which guarantees high robustness to interferences and
asynchronous access for the terminals, at a maximum user data rate of 128 Kbps in a 10 MHz
channel.
STARFISH and SGMS
The Starfish platform provides connectivity to the ISTs and will include the NMS functionalities
described earlier on, required for the QV-SGMS.

A high-level architecture of the current version of the Starfish platform is illustrated in Figure 7, in
which a central hub controls one forward link gateway (FG) serving only one forward link carrier, and
N geographically distributed return link gateways (RGs), managing a subset of L return link carriers.
The forward link makes use of a satellite link using Digital Video Broadcasting – Satellite Version 2
(DVB-S2) [14]. The RLGs are deployed to receive return link signals transmitted by ISTs across the
satellite coverage area. The return link makes use of the F-SIM protocol introduced earlier on, thus
adapting consolidated solutions from terrestrial cellular standards to the satellite scenario, using
asynchronous access and innovative concepts of iterative detection, demodulation and cancellation at
the RLGs, to enable coexistence of a significant number of simultaneous ISTs.
The logical decomposition of the Starfish platform in its components, shown in Figure 7, can be
profitably adapted to the present satellite platform design. Please note that the current architecture
applies irrespectively of the selected frequency ranges, as it can take place in C, Ku, and Ka bands,
and possibly Q/V frequency ranges. Please also note that the production-ready version of the platform
includes a full redundant configuration on both the return and the forward links.
To accomplish the goals of the QV-LIFT project, the Starfish platform is being evolved into a more
flexible and smart system, that takes into account the peculiarities of the Q/V propagation channel.
The first innovation is represented by N multiple gateways that are able to serve a subset of L return
link carriers and a subset of M forward link carriers (and thus, unlike the current version, a gateway will
be able to manage both return and forward links). This represents a significant evolution compared to
the current version of the platform, as it provides an additional degree of freedom: since Q/V carriers
can be significantly impacted by the current weather condition along the satellite link, each gateway
covering a narrow beam is able to use favourable carriers in both the forward and return links.
The second evolution is tied to the introduction of the multi-site time series synthesizer (MTS) tool.
The MTS is a software tool that implements a model of the rainy propagation channel for Q/V feeder
link assessment. Given an N-gateway arrangement (i.e., geographic position of the gateways,
operational frequencies and satellite position) and the statistics of precipitation in each of the N sites,
the MTS produces N time series of rain attenuation across the feeder link. Based on the above
information, the evolved Starfish platform will include a smart gateway management system (SGMS),
which will assess whether an incoming rain fade increases the risk of gateway outage and will take
suitable actions. Based on such models, the SGMS is able to implement the smart gateway and soft
diversity techniques introduced in Section 3.
The above-mentioned techniques can be implemented by letting the SGMS trigger the Starfish
network management system (NMS), that can re-configure the N gateways in real-time, by following
the criteria outlined above. This implies that the evolved Starfish NMS is capable of switching across
different return link and forward link carriers within the same gateway, as well as re-routing ISTs from
one gateway to another one, also controlling the congestion that might occur in the IST population to
be served, and mitigating the impact of the latency introduced during the switch-over procedures.
Figure 7: High level STARFISH Platform architecture

The Alphasat satellite
The Alphasat satellite was launched in summer 2013 hosting the Aldo Paraboni (AP) payload as a
piggyback, build for propagation and communication experiments in Q/V-band [15].
The payload includes an experimental Q/V-band communication payload with a two-channel
transparent transponder with cross-strapping capabilities and with a useful bandwidth of 10 MHz per
channel. It operates with linear vertical polarization on three beams covering respectively North and
South of Italy as well as Austria.
In support to the tests, two Italian ground stations are made available by ASI, one in Spino d’Adda
(ES-Spino) and the other in Tito Scalo (ES-Tito), in the North and South of Italy respectively. Each of
them is equipped with a 4.2 m Q/V-band antenna and basic hub functionalities that are necessary to
perform the desired tests.
The AP system can utilize two 10 MHz Q/V-band channels (linear polarization) in loop-mode or cross-
mode, as depicted in Figure 8 below.
Figure 8: Aldo Paraboni operational modes [15]
Test rationale and architecture
5.
The tests will make use of a mix of existing assets and of new components that will be developed as
part of the project activities.
In Figure 9 below, the components currently under development in QV-LIFT are those highlighted in
yellow.

Q/V
QV-SGMS HUB & MSTS
Alphasat
ES-Tito:
- antenna
- RF front-end
- QV-SGMS Gateway
ES-Spino:
- antenna
- RF front-end
- IST modem
QV-ES:
- antenna
- RF front-end
- QV-SGMS Gateway
Q/V
Q/V
Q/V
QV-AT:
- antenna
- RF front-end
- IST modem
Figure 9: Test environment with existing assets and new developed components
The target of the tests is manifold. On one side, the QV-LIFT project aims at demonstrating the
planned technology developments for the listed LNB, BUC and antennas in Q/V-band (Q/V
communication validation). On the other one, it represents an opportunity to develop and test a set of
hub functionalities (SGMS) that come along with the adoption of Q/V-band for the feeder and/or user
links (Smart Gateways validation).
Q/V communication validation
Two possible antenna reflector diameters for the QV-AT terminal have been considered: 0.45 m and
0.60 m. The respective specifications are presented in Table 5. The 0.45 m terminal specified in Table
5 differs from the one in Table 1 because of a more conservative receiver noise figure of 3 dB. The
0.60 m antenna dish for the terminal leads to an improved G/T so as to reduce development risks
originating from design and production of the MMIC amplifier that will be utilized in the LNB and BUC.
Table 5: 0.45 m and 0.60 m airborne terminal specifications for tests
The link budget calculations for the two terminals are presented in Table 6, considering a
communication among the earth station ES-Tito in Tito Scalo and the QV-AT terminal located in Spino
d’Adda.
The main parameters of the link budget calculations are summarized in Table 7.
Antenna Diameter 0.45 m 0.60 m
Efficiency 0.70 0.70
Frequency (MHz) 37900.00 MHz 37900.00 MHz
Antenna Gain = η.(π.D/λ)² 43.5 dBi 46.0 dBi
Radom Losses 1.0 dB 1.0 dB
Loss + Mismatch 2.0 dB 2.0 dB
Antenna Noise Temperature 121 K 121 K
Repeater Noise Temperature 289 K 289 K
System Noise Temperature 26.7 dBK 26.7 dBK
Gain over Noise Temperature 13.7 dB/K 16.2 dB/K

Table 6: Link budgets towards QV-AT terminal, with 0.45 m and 0.60 m reflectors
ES
-
Tito
–
QV-AT 0.45 m
ES
-
Tito
–
QV-AT 0.60 m
Ground Segment
ES-Tito, 4.2. m ES-Tito, 4.2. m
User Segment
QV-AT Spino, 0.45 m QV-AT Spino, 0.60 m
FWD BW
2 MHz 2 MHz
RTN BW
9.36 MHz 9.36 MHz
FWD C/N
1.66 dB 4 dB
RTN C/N
0.42 dB 2.63 dB
FWD MODCOD/Margins
QPSK 1/3 – 2.2 dB
(0.6 bit/s/Hz)
QPSK 9/20 – 3.08 dB
(0.81 bit/s/Hz)
RTN MODCOD/Margins
CR7680SF16DS1513 – 15.72 dB
(1.38 bit/s/Hz)
CR7680SF16DS1513 – 17.93 dB
(1.38 bit/s/Hz)
Table 7: Summary table of link budgets calculations for QV-AT terminals, with 0.45 m and 0.60 m
reflectors
Configurat ions: ES-Tito -
QV-AT Spino
QV-AT Spino -
ES-Tito
ES-Tito -
QV-AT Spino
QV-AT Spino -
ES-Tito
Forward Link Ret urn Link Forward Link Return L ink
Satellite Longitude 24.8°E 24.8°E 24.8°E 24.8°E
Latitude 40.60° 45.40° 40.60° 45 .40°
Longitude 15.70 ° 9.50° 15.70° 9.50 °
Upli nk elevation to s atelli te
42.1°
35.6°
42.1°
35.6°
Upli nk Range
37628 km
38141 km
37628 km
38141 km
Frequency (MHz) 47900 .00 MHz 48100.00 MHz 479 00.00 MHz 48100.00 MHz
Symbol-Rate 1.82 Msymb/s 7.67 Msymb/s 1.82 Msymb/s 7.67 Msymb/s
MODCOD QPSK 1/3 CR7680SF1 6DS1513 QPSK 9/20 CR7680 SF16DS1513
Spectral Efficiency 0.66 bi ts/symb 0.89 bi ts/symb
0.60 bi ts/Hz 1.38 bits/Hz 0.81 bits/Hz 1.38 bits /Hz
Required Es/No -0.54 dB -15 .3 dB 0.92 dB -15.3 dB
Target Throughput 1.19 Mbi t/s 0.160 Mbi t/s 1.62 Mbi t/s 0.160 Mbi t/s
Roll -off factor 10.00% 22.00% 10.00 % 22.00%
Bandwidth (MHz) 2 .00 MHz 9.36 MHz 2.00 MHz 9 .36 MHz
Uplink EIRP toward satellite 76.3 dBW 56.3 dBW 76.3 dBW 58.8 dBW
Upli nk EIRP Density 73.3 dBW /MHz 46.6 dBW/MHz 73.3 dBW/MHz 49.1 dBW/MHz
IPFD at s atelli te -87 .8 dBW/m² -108.2 dBW/m² -87.8 dBW/m ² -105.7 dBW/m ²
Upli nk Free-Space Loss = 4πD/λ 21 7.6 dB 217.7 dB 217.6 d B 217.7 dB
Atmospheric a ttenuation 1.6 dB 1.9 dB 1.6 dB 1.9 d B
Satellite G/T towards Transmit GS 4.4 dB/K 4.4 dB/K 4.4 dB/K 4.4 dB/K
IPFD - G/T -92.2 d BW/m² - 112.6 dBW/m² -92.2 dBW/m² -110 .1 dBW/m²
Upli nk C/N = EIRP - L + G/T - k. - B 27.5 dB 0.8 dB 27 .5 dB 3 .3 dB
Upli nk C/Im
30.0 dB
16.0 dB
30.0 dB
16.0 dB
Upli nk C/I
23.0 dB
21.0 dB
23.0 dB
21.0 dB
Uplink C/(N+I)
21.1 dB
0.7 dB
21.1 dB
3.0 dB
Upli nk C/No 90.1 dBHz 69.7 dBHz 90.1 dBHz 7 2.2 dBHz
Latitude 45.40° 40.60° 45.40° 40 .60°
Longitude 9.50° 1 5.70° 9 .50° 15.70 °
Downli nk elevation to s atelli te
35.6°
42.1°
35.6°
42.1°
Downli nk Range
38141 km
37628 km
38141 km
37628 km
Downli nk Frequency 37 900.00 MHz 38100.00 MHz 37900.00 MHz 38100 .00 MHz
Receive GS G/T towards Satellite 13.70 dB /K 32.01 dB/K 1 6.20 dB/K 32 .01 dB/K
Downlink EIRP towards GS 39.0 dBW 39.0 dBW 3 9.0 dBW 39.0 dBW
OBO 0.0 dB 0.0 dB 0.0 dB 0 .0 dB
EIRP densi ty 36.0 dBW/ MHz 5 .0 dBW/MHz 36.0 dBW/MHz 5.0 dBW/MHz
Downli nk Free-Space Loss 215.6 dB 215.6 dB 2 15.6 dB 21 5.6 dB
Atmospheric a ttenuation 0.7 dB 0.6 dB 0.7 dB 0.6 d B
Provi sion (poi nting, los ses, etc) 0.5 dB 0 .0 dB 0.5 dB 0 .0 dB
IPFD at Downl ink GS -12 4.3 dBW/m² -12 4.1 dBW/m² -124.3 dBW/m ² -124.1 dBW/m²
Downli nk C/N 1.9 dB 1 4.6 dB 4.4 dB 14 .6 dB
Downli nk C/Im
18.0 dB
20.0 dB
18.0 dB
20.0 dB
Downli nk C/J
21.0 dB
23.0 dB
21.0 dB
23.0 dB
Downlink C/(N+I)
1.7 dB
13.0 dB
4.1 dB
13.0 dB
Downli nk C/No 64.5 dBHz 83.4 dBHz 67 .0 dBHz 83.4 dBHz
Overall C/(N+I) 1.66 dB 0 .42 dB 4.00 dB 2.63 dB
Overall C/(No+I) 64.4 dBHz 69.5 dBHz 66.9 dBHz 71.9 dBHz
Overall Margin 2.2 0 dB 15.72 d B 3.08 dB 17 .93 dB
0.60 m airborne terminal
OVERALL LINK
RX Groun d Station
DOWNLINK
0.45 m airborne terminal
TX Groun d Station
UPLINK

Smart Gateways validation
Soft diversity techniques make use of two system functionalities which are strictly correlated to each
other. In particular, in a simplified scenario, they require first a gateway switching, i.e. the traffic
rerouting from the “impaired” to the available gateway, secondly the terminal shall perform the carrier
switching, as described in Figure 10.
Figure 10: Soft-diversity concept
This refers to the capability of a terminal T1 to switch from the “faded” carrier to the “healthy” carrier,
where for “faded” carrier is intended the carrier generated by a gateway that is operating under
unfavourable weather conditions, conversely the “healthy” carrier is generated by a gateway operating
under good weather conditions. The terminal will thus receive the command from the hub to lock to a
different carrier when requested, namely to switch from the “faded” to the “healthy” carrier so as to not
missing relevant data traffic and keep the service for the user.
The gateway switching will be emulated by employing two earth stations positioned under the same
AP satellite beam, namely the one illuminating South of Italy; the two stations are the existing ES-Tito
in Tito Scalo and the nomadic QV-ES that will be located in Matera, at a distance of around 80 Km
from the first site. Traffic will be routed from ES-Tito to QV-ES and vice-versa to emulate the event of
signal fading that will affect Tito Scalo or Matera alternatively. The ES-Spino acts in this case as the
user terminal. The link budgets are presented in the first 2 columns of Table 8.
The terminal carrier switching capability, as it requires the simultaneous presence of two carriers on
the same user beam, will be tested by employing the ES-Tito and ES-Spino as transmitter and
receiver station respectively. These two earth stations provide indeed a higher EIRP and G/T, thus
providing additional flexibility in the link budget when two carriers are transmitted simultaneously. The
ES-Spino acts as the user terminal and will perform a carrier switch once commanded by the SGMS.
The link budget for 2 simultaneous carriers is presented in the third column of Table 8.
The main parameters of the link budget calculations are summarized in the Table 9.

Table 8: Link budgets for soft diversity tests, transmission of two carriers alternatively and
simultaneously
Transmission of two
carriers alternatively
QV-ES Matera –
ES- Spino
Transmission of two
carriers alternatively
ES-Tito –
ES-Spino
Transmission of two carriers
simultaneously
ES-Tito –
ES-Spino
Ground Segment
QV-ES Matera, 1.5 m ES-Tito, 4.2. m ES-Tito, 4.2. m
User Segment
ES-Spino, 4.2 m ES-Spino, 4.2 m ES-Spino, 4.2 m
FWD BW
10 MHz 10 MHz 2 + 2 MHz
RTN BW
9.36 MHz 9.36 MHz 4.68 + 4.68 MHz
FWD C/N
7.41 dB 10.59 dB 12.78 dB
RTN C/N
7.34 dB 10.41 dB 10.41 dB
FWD MODCOD/Margins
QPSK ¾ – 2.68 dB
(1.35 bit/s/Hz)
QPSK ¾– 5.86 dB
(1.35 bit/s/Hz)
QPSK ¾ – 8.05 dB
(1.35 bit/s/Hz)
RTN MODCOD/Margins
CR7680SF16DS1513 –
22.64 dB
(1.38 bit/s/Hz)
CR7680SF16DS1513 –
25.71 dB
(1.38 bit/s/Hz)
CR3840SF16DS1513 – 25.69
dB
(1.38 bit/s/Hz)
Table 9: Summary table of link budgets calculations for soft diversity tests
Configuratio ns:
QV-ES Matera -
ES-Spino
ES-Spino -
QV-ES Matera
ES-Tito -
ES-Spino
ES-Spino -
ES-Tito
ES-Tito -
ES-Spino
ES-Spino -
ES-Tito
Forward Link Return Link Forward Link Return L ink Forward Link Return Link
Satellite
Longitude 2 4.8°E 24.8°E 24.8°E 24.8°E 24.8°E 24.8°E
Latitude 40.60 ° 45.40° 40.60° 45.40° 40 .60° 45.40°
Longitude 16.70 ° 9.50° 15.70° 9.50 ° 15.70° 9.50°
Uplink el evation to sa tellite
42.3°
35.6°
42.1°
35.6°
42.1°
35.6°
Uplink Ra nge
37614 km
38141 km
37628 km
38141 km
37628 km
38141 km
Frequency (MHz) 4790 0.00 MHz 48100 .00 MHz 47900 .00 MHz 48100.00 MHz 47900.00 MHz 48 100.00 MHz
Symbol-Rate 9 .09 Msymb/s 7.67 Msymb/s 9.09 Ms ymb/s 7.67 Msymb/s 1.82 Msymb/s 3.84 Ms ymb/s
MODCOD QPSK 3/4 CR7680SF16 DS1513 QPSK 3/4 CR7680SF1 6DS1513 QPSK 3/4 CR3840SF1 6DS1513
Spectral Effi ciency 1 .49 bits/s ymb 1.49 bi ts/symb 1.49 bits/symb
1.35 bi ts/Hz 1.38 bi ts/Hz 1 .35 bits/Hz 1 .38 bits/Hz 1.35 bits /Hz 1.38 bits /Hz
Required Es/No 4.73 dB -15.3 dB 4.73 dB -15.3 dB 4.73 d B -15.3 d B
Target Throughput 13.52 Mbi t/s 0 .160 Mbit/s 13.52 Mbit/s 0.160 Mbit/s 2.70 Mbit/s 0.080 Mbi t/s
Roll-o ff factor 10.00% 22.00 % 10.00% 22.00 % 10.00% 22.00%
Bandwidth (MHz) 10.00 MHz 9.36 MHz 10.00 MHz 9.36 MHz 2.00 MHz 4.68 MHz
Uplink EIRP toward satellite 65.8 dBW 76.3 dBW 76.3 dBW 76.3 dBW 73.3 dBW 73.3 dBW
Uplink EI RP Density 55.8 dBW/MHz 66.6 dBW/MHz 66.3 dBW/MHz 66.6 dBW/MHz 70.3 dBW/MHz 66.6 d BW/MHz
IPFD at s atelli te -98.5 dBW/m² -8 8.2 dBW/m² -87 .8 dBW/m² -88.2 dBW/m ² -90.8 dBW/ m² -91.2 dBW/m²
Uplink F ree-Space Loss = 4πD/λ 2 17.6 dB 217.7 dB 217.6 dB 217.7 d B 217.6 dB 217.7 dB
Atmospheric a ttenuation 1.8 dB 1.9 dB 1.6 dB 1 .9 dB 1.6 dB 1.9 dB
Satellite G/T towards Transmit GS 4.4 dB/K 4.4 dB/K 4.4 dB/K 4.4 dB/K 4.4 dB/K 4.4 dB/K
IPFD - G/T -102.9 dBW/m² -92.6 dBW/m² -92.2 dBW/m² -92.6 dBW/m² -9 5.2 dBW/m² -95.6 dBW/m²
Uplink C/N = EIRP - L + G/T - k. - B 9.9 dB 20.8 dB 20.6 dB 2 0.8 dB 24.5 dB 20.8 dB
Uplink C/I m
30.0 dB
16.0 dB
30.0 dB
16.0 dB
30.0 dB
16.0 dB
Uplink C/I
23.0 dB
21.0 dB
23.0 dB
21.0 dB
23.0 dB
21.0 dB
Uplink C/(N+I)
9.6 dB
13.8 dB
18.3 dB
13.8 dB
20.2 dB
13.8 dB
Uplink C/No 79.4 dBHz 89.7 dBHz 90.1 dBHz 89.7 dBHz 87.1 dBHz 86.7 dBHz
Latitude 45.40 ° 40.60° 45.40° 40.60° 45 .40° 40.60°
Longitude 9.50 ° 16.70° 9.50 ° 16.70° 9.5 0° 16.70°
Downlink elevation to s atelli te
35.6°
42.3°
35.6°
42.3°
35.6°
42.3°
Downlink Range
38141 km
37614 km
38141 km
37614 km
38141 km
37614 km
Downlink Frequency 37900 .00 MHz 38100.00 MHz 37900.00 MHz 38 100.00 MHz 37 900.00 MHz 3810 0.00 MHz
Receive GS G/T towards Satellite 31.96 dB/K 26.44 dB/K 31.96 dB/K 32.01 dB/K 31.9 6 dB/K 32.01 dB/K
Downlink EIRP towards GS 39.0 dBW 39.0 dBW 39.0 dBW 39.0 dBW 36.0 dBW 36 .0 dBW
OBO 0.0 dB 0.0 dB 0.0 dB 0 .0 dB 0.0 dB 0.0 dB
EIRP densi ty 29.0 dBW/MHz 5.0 dBW/MHz 29 .0 dBW/MHz 5.0 dBW/MHz 33.0 dBW/MHz 2.0 dBW/MHz
Downlink Free-Space Loss 215.6 dB 215.6 dB 215 .6 dB 21 5.6 dB 215.6 dB 215.6 dB
Atmospheric a ttenuation 0.7 dB 0.7 dB 0.7 dB 0 .6 dB 0.7 dB 0.6 dB
Provis ion (poi nting, los ses, etc) 0.5 dB 0.0 dB 0.5 dB 0.0 d B 0.5 dB 0 .0 dB
IPFD at Downl ink GS -12 4.3 dBW/m² -124.2 dBW/m ² -124.3 dBW/m ² -124.1 dBW/m² -1 27.3 dBW/m² -127.1 dBW/m ²
Downlink C/N 13.1 dB 8.9 dB 13.1 dB 14.6 dB 17.1 dB 14.6 dB
Downlink C/Im
18.0 dB
20.0 dB
18.0 dB
20.0 dB
18.0 dB
20.0 dB
Downlink C/J
21.0 dB
23.0 dB
21.0 dB
23.0 dB
21.0 dB
23.0 dB
Downlink C/(N+I)
11.4 dB
8.4 dB
11.4 dB
13.0 dB
13.6 dB
13.0 dB
Downlink C/No 82.7 dBHz 77.8 dBHz 82.7 dBHz 83.4 d BHz 79 .7 dBHz 80.4 dBHz
Overall C/(N+I) 7 .41 dB 7.34 dB 10.59 dB 10.41 dB 12.78 dB 10.41 dB
Overall C/(No+I) 77.8 dBHz 77.5 dBHz 82.0 dBHz 82.5 dBHz 7 9.0 dBHz 79.5 dBHz
Overall Margin 2.68 dB 22.64 dB 5.86 dB 25.71 dB 8.05 dB 25.69 dB
UPLINK
DOWNLINK
OVERALL LINK
2 Carriers simultaneously
2 Carriers alternative ly2 Carriers alternative ly
2 Carriers alternative ly
TX Ground Station
RX Ground Station

Conclusions
6.
In this paper, we briefly discussed a generic future MSS scenario and some of the functionalities
necessary to tackle deep fades in Q/V-band as investigated in the framework of the QV-LIFT project.
In that context, we introduced the technological developments carried on in the QV-LIFT project
covering the smart gateway management system and the aeronautical terminal including LNB and
BUC. Test setups building upon available ground and space segments of the Italian Space Agency
(Aldo Paraboni payload on Alphasat) are presented. These setups aim at demonstrating the
performance of the gateway and carrier switching. Expected performances have been assessed
through link budget calculations.
Acknowledgements
The authors wish to acknowledge the support of the European Commission in the framework of the
Grant Agreement No. 730104 for the QV-LIFT project under which the presented work was carried
out. Furthermore the authors wish to thank the partners in the project consortium for their good
collaboration and support.
References
[1] http://www.satellitetoday.com/nextspace/2016/09/20/boeing-open-partnerships-leo-
broadband-constellation/
[2] https://www.viasat.com/news/viasat-boeing-complete-preliminary-design-review-
viasat-3-satellites.
[3] L. N. Schiff, “Reducing Service Outages in a Multibeam Satellite System”, US Patent
No. 7,599,657, filed on July 7, 2009.
[4] D. C. Wilkockson, “Soft Diversity satellite Gateway Architecture”, US Patent No.
7,584,297, September 1, 2009.
[5] M. Bergmann, F. Massaro, et al., “Q/V-band feeder links and flexible bandwidth
assignment in future very high throughput satellite (VHTS) communication systems”,
accepted for publication at 23rd Ka and Broadband Communications Conference,
Trieste, Italy, October 16 - 19, 2017.
[6] T. Rossi, F. Maggio, M. De Sanctis, M. Ruggieri, S. Falzini and M. Tosti, "System
analysis of smart gateways techniques applied to Q/V-band high throughput
satellites," 2014 IEEE Aerospace Conference, Big Sky, MT, 2014, pp. 1-10.
[7] Jeannin, N., Castanet, L., Radzik, J., Bousquet, M., Evans, B. and Thompson, P.
(2014), “Smart gateways for terabit/s satellite”. Int. J. Satell. Commun. Network., 32:
93–106.
[8] C.Riva, C.Capsoni, L. Luini, M. Luccini, R. Nebuloni, A. Martellucci, The challenge of
using the W band in satellite communication, Int. J. Satell. Commun. Network.,
2013, 32(3), pp. 187-200.
[9] Riccardo De Gaudenzi, Emiliano Re, and Piero Angeletti. "Smart Gateways
Concepts for High-Capacity Multi-beam Networks", 30th AIAA International
Communications Satellite System Conference (ICSSC).
[10] L. N. Schiff, “Reducing Service Outages in a Multibeam Satellite System”, US Patent
No. 7,599,657, filed on July 7, 2009.
[11] D. C. Wilkockson, “Soft Diversity satellite Gateway Architecture”, US Patent No.
7,584,297, September 1, 2009.

[12] G. Codispoti, G. Amendola, et al., “RF Technologies for the Ground Segment of
future Q/V-band Satellite Systems”, accepted for publication at 23rd Ka and
Broadband Communications Conference, Trieste, Italy, October 16 - 19, 2017.
[13] A. Arcidiacono, et al., “From S-band mobile interactive multimedia to fixed satellite
interactive multimedia: making satellite interactivity affordable at Ku-band and Ka-
band”, Int. J. Satell. Commun. Network., 2016, Vol. 34, Issue 4, pp. 575-601.
[14] ETSI EN 302 307-1 V1.4.1 (2014-11).
[15] F. Di Cola, et al., “Alphasat Aldo Paraboni Payload IOT campaign and Status after
First Year of Operation”, in proc. Aerospace Conference 2016, Big Sky,
Montana(US), Jun. 2016.
[16] Air Interface for Fixed Satellite Interactive Multimedia (F‐SIM): Link Layer and
System Signalling Specification v2.0, R, Confidential, EUTELSAT.