G. Codispoti

Experimental Italian Q/V band satellite network

Broadband technologies are taking a predominant role in the emerging information society. In particular, broadband satellite communication systems, with their global access and broadcasting capabilities, are well suited to answer to the requirements of the information society. This paper focuses on the efforts that are currently spent toward the development of EHF (Extremely High Frequency) satellite communications systems. In particular, Q/V (35–75 GHz) and W (75–110 GHz) bands, represent an almost “free” spectrum resource that could be used to realize the so-called satellite gigabit-connectivity, in order to support innovative broadband applications. This paper presents the most important features of an experimental Q/V band satellite network based on the Alphasat TDP#5 (Technology Demonstration Payload), an ongoing project, funded by the Italian Space Agency, that aims at carrying out communication and propagation experiments over a Q/V band satellite link.

Satellite communication and propagation experiments through the alphasat Q/V band Aldo Paraboni technology demonstration payload

Current high-throughput satellite (HTS) systems for broadband distributed user access are designed following two main concepts: The use of Ka band radio frequency (RF) links both for the forward and for the return link; this choice is due to the congestion of lower frequency bands and to the relatively large bandwidth available in the Ka band. Moreover, the RF technology in the Ka band is mature [1], [2]. The use of multispot coverage: this technique is largely applied to increase the system throughput through frequency reuse and system reconfigurability [2], [3].

Feasibility Study of an Aeronautical-Satellite Broadband Communications Experiment

The development of a technology demonstration payload for experimental broadband communications at Q/V bands has been funded by the Italian Space Agency. This payload will be embarked on the Alphasat satellite for testing fixed broadband ground-satellite communication services. However, the interest in the further experimentation of aeronautical mobile satellite communication services has been recognized. Therefore, in this work the feasibility of an experiment for aeronautical-satellite broadband communications in Q-band is analyzed through the definition of a novel simulation method of an aeronautical satellite multipath channel. Simulation results regarding the performance of DVB-S2 communication links demonstrate the feasibility of the experiment for the provision of broadband communication services.

Q/V-band satellite communication experiments on channel estimation with Alphasat Aldo Paraboni P/L

The Alphasat Aldo Paraboni communication experimental campaign is based on a transparent QIV band transponder hosted as a piggy-back on a GEO satellite. Together with the transparent payload, two beacons having European coverage, one in Ka-band and one in QIV-band, are used to perform propagation experiments. The transparent payload has three spot beams, two over Italy and one over Austria. The University of Rome Tor Vergata-CTIF Italy is the Principal Investigator for the communication experiments and is in charge of operating the payload and the Italian ground stations. The Alphasat Aldo Paraboni experiment is an important step toward the development of future High Throughput Satellite (HTS) systems, able to support hundreds of gigabit/s or terabit/s connectivity. These systems will require: a) use of frequency bands beyond Ka (i.e. Q, V and W bands); b) enhanced frequency reuse; c) use of Propagation Impairments Mitigation Techniques (PIMT). Alphasat Aldo Paraboni payload allows us to perform, for the first time, communication experiments over a Q/V band satellite link with adaptive PIMT, testing: Channel Estimation, Adaptive Coding and Modulation (ACM), up-link power control (ULPC) and space diversity. This paper presents the first results of the communication experiments campaign.

Optimization of ACM algorithms over Q/V-band satellite channels with the Alphasat Aldo Paraboni P/L

Future satellite communication systems providing broadband access to Internet require high throughput connectivity in the order of hundreds of Gbps or Tbps. Radical changes in technologies are needed to support these demanding requirements. One of the most important changes is the use of Q/V band frequencies which offer larger bandwidths with respect to the Ka band. However, Q/V band communication suffers from highly variable propagation losses and the use of Propagation Impairment Mitigation Techniques (PIMTs) is mandatory for an efficient use of radio resources such as power and bandwidth. In this paper we describe the first Q/V band satellite communication experiments that have been performed through the Alphasat “Aldo Paraboni” hosted payload. In particular, experimental results on ACM optimization will be presented.

IKNOW Mission: Payload Design for In Orbit Test of W Band Technology

This paper presents the payload design for an in orbit test of W band technology called IKNOW mission (In orbit Key-test and validatioN Of W band). The increasing demand for frequency bands with large bandwidth availability to satisfy satellite communications applications requirements renders mandatory the need to explore higher and higher frequency ranges. W band (75-110 GHz) could represent the answer to these needs due to the large bandwidth availability, allowing to propose many innovative services that need high-volume transfers. Therefore, the exploitation of W band is foreseen in order to meet the high-quality data transmission for a large number of end users and data-oriented services. The IKNOW mission is a demonstrative experiment foreseen within the phase A2 of the WAVE (W band analysis and verification) project, a study funded by the Italian Space Agency (ASI), which aims at designing and developing W band payloads for telecommunication applications. This paper will be focused on the characterization of the IKNOW mission within the WAVE project devoted to carry out a preliminary channel propagation assessment. Specifically, special attention will be paid to the payload design, particularly critical from the technological point of view at these high frequencies. The basic idea is to develop the receiving/transmitting chain using MMIC devices, in order to fit cost, power and weight constraints, typically limited for a spacecraft. Technological critical items will be highlighted, focusing on the present state of the art and presenting some architectural choices. Moreover, some simulations based on ADS software will be reported in order to simulate the performance of the identified payload configuration.

Alphasat TDP5: Lessons learnt from AIT activities on the payload for communication and propagation experiments at Q/V band

An increasing interest is arising on the exploitation of the Q/V bands for telecommunication applications, in order to cope with the greater and greater demand of bandwidth resources. The development of a mission in the Q/V band was preliminarily investigated by Space Engineering in the framework of an Italian Space Agency (ASI) program dedicated to the Q/V-band. Afterwards, the innovative QV-band Payload - Technology Demonstration Payload (identified as TDP#5) - that will fly on the AlphaSat satellite, has been conceived as a very good occasion for the assessment of the advantages and drawbacks of these new frequency bands. TDP#5 payload has been entirely funded by ASI and developed under an ESA contract awarded to Thales Alenia Space Italia (TAS-I) and Space Engineering (SE) as co-prime contractors. At this point in time, the TDP#5 has been fully integrated at Astrium premises (Toulouse) on Alphasat satellite and successfully tested at ambient conditions. After an introduction with a brief description of TDP#5 mission and payload, this paper focuses on the AIT activities, highlighting those aspects - related to the Q/V bands utilization - that from our experience came out to be the most interesting.

TRANSPONDERS: Research and analysis for the development of telecommunication payloads in Q/v bands

Since the 70s Italy has had a pioneering approach to higher frequencies, at first at Ka band (20/30 GHz) with the Sirio experience (launched in 1978), when such a range was still a frontier, and then with Italsat F1 and F2 experiments in the 90s [1], studying Q and V bands in addition to Ka one as well. After those experiences, Italy through the Italian Space Agency (ASI) was one of the first European countries that have made an effort toward the exploitation of Q/V band in telecommunications. In 2004 ASI funded a feasibility study (phase A), called TRANSPONDERS, Italian acronym for “research, analysis and study of Q/V payloads for telecommunications”, aimed at studying and designing a payload to be used to fully characterize the channel at Q/V bands and to test novel adaptive interference/fading mitigation techniques such as ACM (Adaptive Coding and Modulation). Finally, the feasibility and performance of preliminary broadband services in such frequencies can be verified through this study .A new phase has recently started (April 2008), called TRANSPONDERS-2 and leaded by Space Engineering S.p.A., to continue the achievements gained during the first phase. In this scenario, it is mandatory to identify pre-operative experimental missions aiming at fully verifying the feasibility of future Q/V bands satellite telecommunication applications. The experimental goals are mainly to test the effectiveness of Propagation Impairment Mitigation Techniques (PIMTs) [2] in such frequency bands and the minimization of implementation risks for operative system characterized by a series of technological challenges.

Alphasat Aldo Paraboni payload IOT campaign and status after the first year of operation

The Alphasat satellite was launched on 25 July 2013. The Aldo Paraboni technology demonstration payload, funded by ASI under ESAs ARTES Programme, was embarked as an hosted payload on Alphasat. This Technology Demonstration Payload (identified as TDP5 and recently renamed “Aldo Paraboni”) was implemented under an ESA contract awarded in co-contractorship to Space Engineering and Thales Alenia Space Italia (TAS-I) which conceived the experimental mission and industrialised the subsystems. The Aldo mission is composed of two main elements: a Communication Experiment mission, which aims at assessing the performance of communication links at Q/V Bands; and a Scientific Experiment mission implemented through two beacons at Ka and Q Bands, which aims at characterizing propagation phenomena at these frequencies. During the In Orbit Test campaign of the above two mission components, TDP5 demonstrated compliance to the requirements and the nominal conditions of the Payload. The main topics of this paper are the description of the In Orbit Test requirements and the discussion of tests results. The good health of the Payload is demonstrated by the agreement of the results with the predictions that were calculated on the basis of the results of the on ground test campaign. The Commissioning and IOT campaign of Aldo Paraboni was performed over 3 distinct sessions: · Commissioning: 17-18 September 2013 · IOT Part 1: 10-18 October 2013 · IOT Part 2: 4-8 November 2013 This work is only related to the verification of the performance of the space segment, the Q/V-Band Payload, also referred to as the TDP5. TDP5 stands for Technical Demonstrator Payload #5 and it is formally the 5th experimental (i.e. technological demonstrator) hosted payload of the Alphasat programme.

The integration phase of ALPHASAT Technology Demonstration Payload #5 Mission Segment

The paper describes the integration phase of the ALPHASAT Technology Demonstration Payload #5 (TDP#5) Mission Segment that, in conjunction with the TDP#5 payload, embarked in the Alphasat Satellite will allow the execution of communication experiments at Q and V frequency bands, and propagation experiments at Q and Ka bands. The TDP5#5 Mission Segment (TDP#5-MS) major constituents are two Italian Grounds Stations and three different control centres, one for the mission and two dedicated to each of the above mentioned experiments. Furthermore, the TDP#5-MS has been conceived in order to operate also with a third foreign Ground Station located in Austria at the Joannehum Research Institute.